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1. 26 B Unsatisfactory Pattern If the pattern displayed shows a short or no downspike for the disconnected spark plug as illustrated in Figure 8 3 there is a secondary insulation problem Short or No Negative Spike SECONDARY INSULATION TEST Unsatisfactory Pattern BPI FIGURE 8 3 1 If an unsatisfactory pattern exists for all spark plugs cylinders check for a Cracked or carbon tracking of the coil tower b Defective coil wire c Cracked or carbon tracking of the rotor d Cracked or carbon tracking of the center tower of distributor cap If one or more but not all spark plugs cylinders test unsatisfactorily check for a Cracked or carbon tracking of one or more of the distributor cap towers b Defective spark plug wires Refer to step three be low for instructions on testing individual spark plug wires Defective Spark Plug Wire Test If the above test re sults indicate faulty spark plug wires perform the fol lowing procedure to determine which spark plug wires are defective a Select the first wire that produced an unsatisfac tory pattern in the test above and disconnect the wire at the distributor cap Perform the Secondary Insulation Test for this spark plug wire If the pattern for this spark plug is unsatisfactory when tested with the spark plug end discon nected and is satisfactory with distributor cap end disconnected the spark plug wire is defective Repeat ste
2. 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 7 3 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any spark plug wire with boot at the spark plug end except the wire leading to the No 1 spark plug Do not allow this wire to arc to ground The INDUC TIVE PICK UP 8 should be clamped to the No 1 spark plug wire as instructed above in paragraph 7 2 D D Engine On Start vehicle engine E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 7 2 and 7 3 The pattern displayed on the scope screen should match the normal pattern illustrated in Fig ure 7 2 The pattern illustrated is for BPI Oscillation detail on el
3. H Test Remaining Spark Plug Wires Repeat the test procedure with each spark plug wire except the wire lead ing to the first spark plug in the firing order see next step Make a note of which cylinder patterns are normal and which are unsatisfactory Test No 1 Spark Plug Wire To test the No 1 spark plug wire move the INDUCTIVE PICK UP to a spark plug wire that has already been tested satisfactorily Disconnect and test the No 1 spark plug wire 8 20 TEST RESULTS A Normal Pattern The normal basic scope pattern of the spark plug for the Prestolite BID Ignition System has an ex tra waveform in dwell section Refer to Figure 8 14 The downspike of the pattern for the disconnected spark plug should be approximately one third as long as the upward spike of the pattern as illustrated in Figure 8 14 If this pat tern is displayed the secondary insulation is satisfactory 34 Negative _ Spike SECONDARY INSULATION TEST Normal Pattern BID FIGURE 8 14 Short or No Negative Spike SECONDARY INSULATION TEST Unsatisfactory Pattern BID FIGURE 8 15 B Unsatisfactory Pattern If the pattern displayed shows a short or no downspike for the disconnected spark plug as illustrated in Figure 8 15 there is a secondary insulation problem 1 If an unsatisfactory pattern exists for all spark plugs cylinders check for a Cracked or carbon tracking in the coil tower b Defective coil wire c Cracked or ca
4. CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 14 2 HOOK UP PROCEDURE Refer to Figure 14 1 The scope controls and cables are numbered in Figure 14 1 asa reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 14 1 2 CRANKING SPEED Hook Up COIL OUTPUT AT FIGURE 14 1 oo WARNING When making electrical test connections to
5. FIGURE 17 7 CAUTION When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion CAUTION Do not allow PICK UP COIL TEST LEAD clips to touch each other or the vehicle ground C PICK UP COIL TEST LEAD 12 Connections 1 Scope Plug the yellow PICK UP COIL TEST LEAD 12 connector into the yellow socket on the back of the scope 2 Vehicle a Disconnect the three wire connector between the distributor and the electronic module b Connect the PICK UP COIL TEST LEAD clips to the distributor side of the connector as shown in Figure 17 7 D Select Function Rotate FUNCTION SELECTOR 3 to DISTRIBUTOR PATTERN position 57 E Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop F Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH 17 11 TEST PROCEDURE A Select Function Ensure the FUNCTION SELECTOR 3 is set to the DISTRIBUTOR PATTERN position B Crank Engine Ha
6. Ge MANUAL Although the tests in this manual are presented in the most efficient order ee ts cct critical to follow this order Each test contains a complete set of hook DIS CLIC IT E aeto the particular ignition system berg tested This allows the tech Kee Zeie ris thertests or otrer er cescecfcatiors When performing A eee at erences cetween test instructions are often 23 2 ger7eral guide for engine tune up and TEST SELECT ON FOR VEHICLE Ti getem aT 17 tests apply to the specific test vehicle consult ns n e e ier 2 2 v 4 H h 1 5 SAFETY INFORMATION Terr ztratit s tara rformation which is especially critical to personnel E EE aS es rc o nterrupt the text The terms WARNING CAUTION and WARNING 7 77 22s are used to emphasize conditions in the operation of the equipment that could cersomnel CAUTION Caution notices are used to emphasize conditions in the operation of the equipment that couic cause damage to equipment 7 D NOTE Notes call attention to information that is especially significant in understanding or operating this equipment 1 6 GENERAL INFORMATION A Oscilloscope Testing The Model 161 21056 Diagnostic Oscilloscope provides a visual means of ob serving the performance of an automobile ignition system Using the oscilloscope scope and this manua the technician follows hook up and test procedures to test for specific ignitio
7. Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 11 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the DISTRIBUTOR PATTERN position B Adjust Pattern With the PATTERN POSITION CON TROL 5 and PATTERN LENGTH CONTROL 6 adjust the ignition pattern of one cylinder so that it completely fills the screen C Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 11 2 11 3 and 11 4 The pattern displayed on the scope screen should match the normal pattern illustrated in Figure 11 2 D Engine Off Turn vehicle engine off 11 4 TEST RESULTS A Normal Pattern The proper dissipation of energy in both the coil condenser section and the dwell section of the ignition scope pattern appears as several diminishing oscillations Several oscillations that gradually diminish in size COIL CONDENSER TEST Normal Pattern BPI FIGURE 11 2 B Unsatisfactory Pattern An unsatisfactory pattern lacks oscillations in either or both the coil condenser section and the dwell section of the ignition scope pattern 1 If the pattern lacks oscillations in the coil condenser section only check for a leaky condenser Lack of oscillations COIL CONDENSER TEST Unsatisfactory Pattern BPI FIGURE 11 3 2 If the pattern lacks oscillations throughout check for a defective coil This pattern may oc
8. The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive battery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 7 7 ELECTRONIC IGNITION MODULE MAXIMUM COIL OUTPUT TEST Hook Up SSI DS Systems FIGURE 7 7 CAUTION When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion or scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connection
9. except the wire leading to the No 1 spark plug see I below Do not move a loose spark plug wire out of normal operating position but keep it from grounding The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 8 2 D D Engine On Start vehicle engine E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 8 2 and 8 3 The pattern displayed on the scope screen should match the normal pattern illustrated in Figure 8 2 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire H Test Remaining Spark Plug Wires Repeat the test procedure with each spark plug wire except the wire lead ing to the first spark plug in the firing order see next step Make a note of which cylinder patterns are normal and which are unsatisfactory Test No 1 Spark Plug Wire To test the No 1 spark plug wire move the INDUCTIVE PICK UP to a spark plug wire that has already been tested satisfactorily Disconnect and test the No 1 spark plug wire 8 4 TEST RESULTS A Normal Pattern The downspike of the pattern for the disconnected spark plug should be approximately half as long as the upward spike of the pattern as illustrated in Figure 8 2 If this pattern is displayed the secondary insula tion is satisfactory Negative Spike Su N SECONDARY INSULATION TEST Normal Pattern BPI FIGURE 8 2
10. 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 8 11 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any spark plug wire with boot at the spark plug end except the wire leading to the No 1 plug see I below Do not move a loose spark plug wire out of normal operating position but keep it from arcing to ground The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 8 10 D D Engine On Start vehicle engine E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results figures 8 8 and 8 9 The pattern displayed on the scope screen should match the normal pattern illustrated in Fig ure 8 8 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire H Test Remaining Spark Plug Wires Repeat the test procedure with each spark plug wire except the wire lead ing to the No 1 spark plug see next step Make a note of which cylinder patterns are normal and which are unsatisfactory L Test No 1 Spark Plug Wire To test the No 1 spark plug wire move the INDUCTIVE PICK UP to a spark plu
11. 15 1 asa reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 15 1 ROTOR GAP TEST Hook Up FIGURE 15 1 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure the the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp th
12. 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 8 19 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any spark plug wire with boot at the spark plug end except the wire leading to the No 1 spark plug see below Do not move a loose spark plug wire out of normal operating position but keep it from arcing to ground The IN DUCTIVE PICK UP should be clamped to the first in firing order spark plug wire as instructed above in paragraph 8 18 D D Engine On Start vehicle again E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 8 14 and 8 15 the pattern displayed on the scope screen should match the normal pattern illustrated in Figure 8 14 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire
13. Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to DISTRIBUTOR PATTERN F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature i Adjust Engine Speed Adjust engine speed as required to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 Spark plug wire with resistance wire just for this test K Adjust Position Controls
14. Compare the pattern displayed on the scope while the engine is cranking with the patterns il lustrated below in Test Results Figures 17 2 and 17 3 The pattern displayed on the scope screen should match the normal pattern illustrated in Figure 17 2 While the engine is cranking gently wiggle or flex the green and white wires from the pick up coil while observing the scope display The pattern shown in Figure 17 2 should remain constant If there is any sign of erratic operation check the pick up coil wires for insulation nicks cuts or wear and check the ter minals for good connections D Reconnect Remove test leads reconnect all wires and replace the distributor cap 17 4 TEST RESULTS A Normal Pattern MAGNETIC PICK UP COIL TEST Normal Pattern HEI FIGURE 17 2 55a B Unsatisfactory Pattern A line with no vertical ampli tude is an unsatisfactory pattern NO AMPLITUDE ao MAGNETIC PICK UP COIL TEST Unsatisfactory Pattern HEI FIGURE 17 3 If an unsatisfactory pattern exists the magnetic pick up coil is not functioning properly Check the pick up coil with an ohmmeter There should be no reading infinity from either wire to ground and the resistance across the coil should be between 500 1500 ohms SECTION II CHRYSLER Electronic Systems 6 and 8 Cylinder Only 17 5 DESCRIPTION Some electronic ignition systems use a magnetic pickup coil and reluctor assembly in place of co
15. Figure 8 13 The scope controls and cables are numbered in Figure 8 13 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 8 13 2 ELECTRONIC IGNITION MODULE SECONDARY INSULATION TEST Hook Up BID FIGURE 8 13 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow C
16. KV MAXIMUM COIL OUTPUT TEST Unsatisfactory Pattern GM HEI FIGURE 7 6 If an unsatisfactory pattern exists check for a Defective coil b Low battery voltage c Excessive resistance in primary circuit reducing input to ignition coil Defective secondary insulation on ignition wires Defective ignition module Defective rotor and or distributor cap d e f SECTION lil FORD SSI DS SYSTEMS 7 9 DESCRIPTION For any ignition system to function properly the ignition coil must be able to produce a high secondary voltage Failure of the ignition coil to produce adequate voltage may cause the engine to misfire under load or at high speed The maximum secondary voltage produced by an ignition coil can be measured in this test to ensure adequate voltage CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 7 10 HOOK UP PROCEDURE Refer to Figure 7 7 The scope controls and cables are numbered in Figure 7 7 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested
17. Ove tena See teas 15 3 TEST PROCEDURE 22 404 de IS wee eee ES Ree ASA A aaa eee ae 15 4 TEST RESULTS ta o EEN A Normal Panenn cou tices coca pun EA E ORR eS B Unsatisfactory Pattern escorts AA oe dees eee ee ARS Section Il GM HEI and FORD TFI Systems 15 5 DESCRIPTION risa AA eee A panes 15 6 HOOK UP PROCEDURE tt DS A wae eee ee cea ey See Bere a 15 7 TEST PROCEDURE tai dE Mer eer svi in seh eae 15 8 TESTIRESULTOS geet Me ee ea eee ee ae One See eee Reena tony A Normal Patern ar E Reo eae EE B UNS ataco Patern a a rd a and Fea asa a A Rca aan aeons CHAPTER 16 ALTERNATOR TEST 16 1 DESCRIPTION Suar toma cote ahi et ae a pete ant hens E 16 2 HOOK UP PROCEDURE cartero PAG Died dol UGG So ve ak et a ale oes Sey eas eats See 16 3 TEST eer REENEN 16 4 TEST RESULTS mrien tok wnc EE Ri Normal E NEE Bo Unsatisfactory Pattern s0cies plane ae ta Ree eee habe eh Pu old eee RE CHAPTER 17 MAGNETIC PICK UP COIL TEST Section GM HEI System 17 1 DESCRIPTION As hd ned thea as 17 2 HOOK UP PROCEDURE soea dude teen eon aetna OEA 17 3 TEST PROCEDURE tia A eee Gee oe ene ha coma ba eas e ER RE E KEE Ae Normal Patent caia AAA ARA B Unsatisfactory Pattern SA AE AA OS da Section Il Chrysler Electronic Ignition Systems 6 and 8 Cylinder Only 17 5 DESCRIPTION agredir Kk a 17 6 HOOK UP PROCEDURE Sat ea tits vege eae hla a a 17 7 TEST PROCEDURE toda ro ad E Ad a Shine eau A eN 17 8 TEST RESULTS cyte tated E E Ae
18. RESULTS A Normal Pattern Resistance in the secondary circuit is normal when the spark line is tilted downward slightly from the spark voltage line in suppressed ignition systems or nearly level in unsuppressed ignition systems Spark line nearly level for unsuppressed systems and slightly tilted downward from spark voltage for suppressed systems SECONDARY RESISTANCE TEST Normal Pattern BPI FIGURE 13 2 B Unsatisfactory Pattern Excessive resistance appears as a steeply angled spark line Very high angle of spark line SECONDARY RESISTANCE TEST Unsatisfactory Pattern BPI FIGURE 13 3 If an unsatisfactory pattern exists for all cylinders check for a Corroded coil wire terminals b Open coil wire or radio suppressor C Burned carbon button in the distributor cap d Burned distributor cap segments e Burned rotor tip If one or more but not all cylinders test unsatisfac torily check for a High resistance or open spark plug wires Corroded distributor cap towers Burned distributor cap segements Defective spark plugs 1 Cracked porcelain insulator 2 Open internal Resistor Resistor type plugs only b C d CHAPTER 14 COIL OUTPUT AT CRANKING SPEED TEST BREAKER POINT IGNITION SYSTEM 14 1 DESCRIPTION A fault in the primary circuit or a defective coil may cause an engine to be hard to start or fail to start This test determines if these systems are the cause of a starting problem
19. Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 13 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the DISTRIBUTOR PATTERN position B Adjust Pattern With the PATTERN POSITION CON TROL 5 and PATTERN LENGTH CONTROL 6 adjust the ignition pattern of the number one cylinder so that it completely fills the screen C Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results figures 13 2 and 13 3 The pattern displayed on the scope screen should match the normal pattern illustrated in Fig ure 13 2 The pattern illustrated is for BPI Oscillation detail on electronic ignition systems will vary as shown in chapter 5 46 D Parade Pattern Turn the PATTERN POSITION CON TROL 5 counterclockwise and compare the patterns of each cylinder with the patterns illustrated below in Test Results E Engine Off Turn vehicle engine off 13 4 TEST
20. UP 9 or GM HEI PATTERN CA PACITIVE PICK UP 10 Connections 1 CAPACITIVE PICK UP 9 Use the CAPACITIVE PICK UP 9 for all systems with the ignition coil mounted externally Figure 6 1 A 4 B a Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope b Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coll wire 2 HEl PATTERN CAPACITIVE PICK UP 10 Use the HEI PATTERN CAPACITIVE PICK UP 10 for HEI systems with the ignition coil mounted internally in side the distributor cap Figure 6 1C a Scope Plug the yellow HEI PATTERN CAPACI TIVE PICK UP 10 connector into the yellow socket on the back of the scope Vehicle Clip the HE PATTERN CAPACITIVE PICK UP 10 onto the top of the distributor cap D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle a Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope ha
21. a db A ANEMIA e AR RS NAAA B Ursatistact ry Pattern a Rs aa Section V American Motors BID Ignition System 8 17 DESCRIPTION ens AAA ta 8 18 HOOK UP PROCEDURE ocaso aro area ld 8 19 TEST PROCEDURE adria ness ches yo Er AN eed 8 20 RE KEE AS Norma E WEEN LEE ee A EE CHAPTER 9 SPARK VOLTAGE UNDER LOAD TEST Section Breaker Point All Chrysler Electronic Ford Solid State and Dura Spark and Prestolite BID Ignition Systems 9 1 DESCRIPTION sisas aras ta ano bate ms 9 2 HOOK UP PROCEDURE ed NENNEN d RN a bene ex ous 9 3 TEST PROCEDURE oia ied cos od ad o o Gace ia 9 4 TEST RRESULES lt a ate Ea e A eg EIN E WEE ile B Unsatisfactory Pattern Section Il GM HEI and FORD Thick Film ignition Systems 9 5 DESCRIPTION boya ias e 9 6 HOOK UP PROCEDURE 1 toa ri an en sees 9 7 TEST PROCE DURE rd a toate loos OEE a dee etme ein riera 9 8 TESTRESULTS EE A Normal Patern eva a cane EE pd B Unsatistactory PASTO A AS EA ees ARA Pee hee CHAPTER 10 DWELL AND VARIATION IN DWELL TEST BPI and GM HEI Ignition Systems 10 1 Elei a Le WEE 10 2 HOOK UP PROGEDURE sour AEREA EE 10 3 TEST PROCEDURE a A AS ee 10 4 TESTRESUETS cda ads ds A te eee ae pea ok Ay Normal Pattern a a hire eee Mea RES B sUnsatistactory Patern aiii 6 ot Mate dite adore ea ees Wolo es 10 5 AME lie 404 2 O Reacts e da to O CHAPTER 11 COIL CONDENSER TEST Section Breaker Point Ignition System 11 1 DESCRIPTION WEE 11 2 HOOK UP PROCEDURE
22. calibra tion of scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable
23. cause serious burns The jack supplied with the vehicle should be used only for changing wheels Never crawl under car or run en gine while vehicle is on jack When making electrical test connections to the vehicle do not use the carburetor or other fuel system compo nents as a ground connection as a spark could ignite the gasoline vapors and cause a fire or an explosion Do not let test cables rest or fall on or near hot or moving engine parts Use caution when disconnecting ignition cables Pull ca bles carefully at the boot with the proper tool Always turn the scope OFF before disconnecting 7 the battery If within 1 year from the date of purchase this automotive test instrument fails due to a defect in material or workmanship RETURN IT TO NEAREST SEARS STORE IN THE UNITED STATES and Sears will repair or replace it free of charge This warranty gives you specific legal rights and you may also have other rights which vary from state to state SEARS ROEBUCK AND CO e DEPARTMENT 698 731A SEARS TOWER e CHICAGO IL 60684 CHAPTER 1 INTRODUCTION 1 1 INTRODUCTION This owner s manual describes the Sears Craftsman Model 161 21056 Diagnostic Oscilloscope and the tests that it can do Prior to performing any oscilloscope test however it is important thatthe technician understands how to use this manual and how to apply the tests described for the specific venicie being serviced IMPORTANT CONSULT T
24. detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope L9G 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 8 7 ELECTRONIC IGNITION MODULE SECONDARY INSULATION TEST Hook Up EIS FIGURE 8 7 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns C CAPACTIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle a C
25. mechanics is to WARNING READ CAREFULLY Read this Operation Instruction Manual and these Rules for Safe Automotive Testing carefully Failure to follow instructions and safety rules could resultin se rious bodily injury and or damage to the instrument 10 11 12 13 14 15 16 Vds FULL ONEYEAR WARRANTY Never add acid to carefully blow across the top of the battery to remove any hydrogen gas accumulation before connecting or dis connecting battery clips a caver placed in service ocr spatterirg of e ectro yte e S 5 Keep hands hair necktie loose Con g 27798 2215 well away from fan blades fan belt power stes 72 air conditioner belt and other moving engine pants as rious injury could result from entanglement Do not touch hot exhaust manifold radiator or high volt age spark plug and coil terminals Spark voltages are not normally lethal but an involuntary jerk of the hands or arms caused by electrical shock may result in injury Never look directly into carburetor throat while engine is cranking or running A sudden backfire can cause seri ous burns To avoid the possibility of a flash fire do not smoke or permit flame or spark to occur near carburetor fuel line fuel filter fuel pump or other potential sources of spilled gasoline or gasoline vapors Never remove radiator cap while the engine is hot Hot coolant escaping under pressure can
26. plug wires perform the fol lowing procedure to determine which spark plug wires are defective a Replace one spark plug wire at a time with a Known good wire until the defective one s is found b Repeat Secondary Insulation Test SECTION Ill EIS ALL CHRYSLER SYSTEMS 8 9 DESCRIPTION The secondary ignition circuit is the path of voltage from the coil to the gap of each spark plug s electrodes This test checks the secondary ignition circuit for proper insulation A break in the insulation of the sec ondary circuit will cause voltage to arc to ground instead of to the corresponding spark plug and cylinder This re sults in the misfire of the spark plug CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 8 10 HOOK UP PROCEDURE Refer to Figure 8 7 The scope controls and cables are numbered in Figure 8 7 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in
27. proper insulation A break in the insulation of the sec ondary circuit will cause voltage to arc to ground instead of to the corresponding spark plug and cylinder This re sults in the misfire of the spark plug CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 8 2 HOOK UP PROCEDURE Refer to Figure 8 1 The scope controls and cables are numbered in Figure 8 1 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive battery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator
28. spark plug firing condition for one or all of the cylinders too high or too low 25 KV DISTRIBUTOR Pattern Display FIGURE 4 2 C Distributor Pattern Refer to Figure 4 2 This function display is the same as the 50 KV COIL display but is twice the height on the screen When properly adjusted this pat tern provides the technician with an easy to read pattern of any specific cylinder Through measurement and observa tion the technician can determine and locate an abnormal ignition condition within the firing of a specific cylinder This is not a calibrated voltage scale but is provided to illustrate the waveshapes in the Spark Line and oscillation which must be present for a normal system SUPERIMPOSED 25 KV Pattern Display FIGURE 4 3 D 25 KV Superimposed This function displays the pat terns of the spark ignition voltages of all the cylinders at the same time The patterns for all the cylinders appear super imposed upon each other as illustrated in Figure 4 3 When properly adjusted this display provides the technician with as easy to read comparison of all the cylinders and in par ticular dwell variations between cylinders Ll 25 KV SPARK Pattern Display FIGURE 4 4 NYY ALTERNATOR PATTERN DISPLAY FIGURE 4 5 E Alternator Refer to Figure 4 5 This function displays the ripple content of the test vehicle alternator When pro perly adjusted this display provides the technician with a waveform pat
29. until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test 49 K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 15 3 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 25 KV SPARK position Tt CAUTION Selection of spark plug wires to be disconnected is critical on Ford Electronic ignition Systems Unless properly selected damage to the ignition system electronics may result DO NOT DISCONNECT V 8 engines No 1 or No 8 spark plug wire V 6 engines No 1 or No 4 spark plug wire T6 engines No 3 or No 5 spark plug wire 4 Cylinder engines No 1 or No 3 spark plug wire C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any properly selected spark plug wire with boot at the spark plug end except the wire leading to the No 1 spark plug Do not allow this wire to arc to ground The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 15 2 D D Ground Distributor Terminal Insert a metal prod into the open distributor terminal and gro
30. ve hicle do not use the carburetor or other fue system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion CAUTION Do not allow PICK UP COIL TEST LEAD clips to touch each other or the vehicle ground C PICK UP COIL TEST LEAD 12 Connections 1 Scope Plug the yellow PICK UP COIL TEST LEAD 12 connector into the yellow socket on the back of the scope 2 Vehicle a Disconnect the two wire connector between the distributor and the electronic module NOTE Some Chrysler Electronic Ignition Systems use two pick up coils Start and Run Each of these coils may be tested separately using the same procedure b Connect the PICK UP COIL TEST LEAD clips to the distributor side of the connector as shown in Figure 17 4 E Select Function Rotate FUNCTION SELECTOR 3 to DISTRIBUTOR PATTERN position F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH 17 7 TEST PROCEDURE A Select Function Ensure that FUN
31. wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 7 11 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position CAUTION Selection of spark plug wires to be disconnected is critical on Ford Electronic Ignition Systems Unless properly selected damage to the ignition system electronics may result DO NOT DISCONNECT V 8 engines V 6 engines L6 engines 4 Cylinder engines No 1 or No 8 spark plug wire No 1 or No 4 spark plug wire No 3 or No 5 spark plug wire No 1 or No 3 spark plug wire C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any properly selected spark plug wire with boot at the spark plug end except the wire leading to the No 1 spark plug Do not allow this wire to arc to ground The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 7 10 D D Engine On Start vehicle engine E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 7 8 and 7 9 The pattern displ
32. 1 part of INDUCTIVE PICK UP to the positive output stud of the alternator If it is in convenient or dangerous to access the alternator stud connect the alligator clip to the positive terminal of the battery Connecting the alternator LEAD to the battery may result in a pattern smaller in amplitude than when connected to the alternator but of the same shape D Select Function Rotate FUNCTION SELECTOR 3 to the ALT position E Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop F Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizon tal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH G Start Engine Start the engine and allow it to warm to normal operating temperature H Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamp is clean and completely encloses the No 1 spark plug wire 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stab
33. 18 ADDITIONAL SCOPE PATTERNS 18 1 GENERAL Most ignition problems detected with an oscilloscope are represented by easily recognizable display patterns However some unusual patterns are dis played occasionally The following paragraphs illustrate and explain the most common of these non standard pat terns 18 2 TURBULENCE A broken spark line section in the pattern as illustrated in Figure 18 1 indicates high com pression and turbulence This pattern may be normal if dis played when testing a high compression engine but on older cars it indicates excessive carbon deposits or valve malfunction Pattern Indicating Turbulence FIGURE 18 1 18 3 INDUCTION LEAKS If the pattern illustrated in fig ure 18 2 is displayed for one or more but not all cylinders a manifold leak is indicated Air may be entering the com bustion chamber and causing an abnormally lean fuel mix ture condition Pattern Indicating Induction Leaks FIGURE 18 2 18 4 DEFECTIVE COIL A pattern that lacks oscillation throughout as illustrated in Figure 18 3 indicates a defec tive coil For additional information refer to Chapter 11 NOTE This pattern may also occur when the scope is used in conjunction with an automobile analyzer that is set at the DWELL or POINTS RESISTANCE posi tion Disconnect the analyzer to determine if it is the cause of the problem before testing the coil Lack of oscillations Pattern Indicating Defect
34. AFTSMAN Diagnostic Oscilloscope Controls Connections and Accessories FIGURE 2 1 CHAPTER 3 TEST DESCRIPTIONS 3 0 GENERAL The Sears Craftsman Diagnostic Oscillo scope may be used to perform many engine tests The twelve most common tests are outlined below and de scribed in detail in the following chapters CAUTION The scope obtains its power to operate from the 12 volt car battery If you are servicing a vehicle with a 6 volt battery system you must use a 12 volt auxiliary battery for the scope Connect a jumper wire be tween the negative terminal of the auxiliary battery and ground on the vehicle being tested Connect the red power lead clip from the scope to the positive terminal of the auxiliary battery and the black clip to the negative ground of the vehicle under test 3 1 SPARK POLARITY TEST Incorrect polarity in the primary or secondary circuit can result in a 20 40 greater voltage requirement to fire the spark plugs and may cause the engine to misfire under load or at high speed This test checks for correct polarity in the entire ignition circuit Re fer to Chapter 6 3 2 MAXIMUM COIL OUTPUT AVAILABLE VOLTAGE TEST For any ignition system to function properly the ig nition coil must be able to produce high secondary voltage Failure of the ignition coil to produce adequate voltage may cause the engine to misfire under load or at high speed The maximum secondary voltage produce
35. APA CITIVE PICK UP 10 Connections 1 CAPACITIVE PICK UP 9 Use the CAPACITIVE PICK UP 9 for HEI and TFI systems with the ignition coil mounted externally Figure 8 4A a Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope b Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire 2 HE PATTERN CAPACITIVE PICK UP 10 Use the HEI PATTERN CAPACITIVE PICK UP 10 for HEI systems with the ignition coil mounted internally un side the distributor cap Figure 8 4B a Scope Plug the yellow HEl PATTERN CAPACI TIVE PICK UP 10 connector into the yellow socket on the back of the scope b Vehicle Clip the HEl PATTERN CAPACITIVE PICK UP 10 onto the top of the distributor cap D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 07 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for appr
36. APACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP
37. CONTROL 322 to adjust the vertical position of the pattern on the 13506 screen gt PATTERN POSITION CONTROL sed to adjust the horizontal position of the pattern on the ope screen 6 PATTERN LENGTH CONTROL Used to adjust the horizontal length of the pattern on the scope screen 7 POWER LEAD Comnects the scope to the 12 volt battery of the vehicle being tested or an auxiliary 12 volt battery 8 INDUCTIVE PICK UP When clamped over the wire of the first spark plug in the vehicle s firing order the Scope displays patterns in firing order for the cylinders without regard to the engine speed or number of cylinders 9 CAPACITIVE PICK UP When clamped over the high tension ignition coil wire the Scope displays the secondary high voltage pattern 10 HEl PATTERN CAPACITIVE PICK UP Connects to the top of the General Motors HEI integral coil distributor systems and is used in place of the CAPACITIVE PICK UP Item 9 above 11 ALTERNATOR LEAD WITH BLUE CLIP Connects to the Positive terminal of the alternator or battery terminal when alternator is inaccessible Scope displays the voltage pattern 12 PICK UP COIL TEST LEAD Connects to the CAPACITIVE PICK UP socket on the back of the scope and to the magnetic pick up coil of electronic ignition systems Tests the magnetic trigger unit in the distributor on electronic ignition systems 13 FIBER PLIERS Used to remove the spark plug wires IUOIHTEHODI0U CR
38. CT 4 cylinder Domestic EIS MMC Chrysler Electronic Ignition System Mitsubisr ELB Chrysler Electronic Lean Burn ESC Chrysler Electronic Spark Control SSI Motorcraft Solid State Ignition SE DS Ford Dura Spark DSH Ford Dura Spark Il DS IH Ford Dura Spark Ill sl Ford Thick Film Integrated Ignition TFI I Ford Thick Film Integrated Ignition TFI IV Ford Thick Film Integrated Ignition IV HEI General Motors Delco Remy High Energy lar BID Prestolite Breakerless Inductive Discharge CHAPTER 6 SPARK POLARITY TEST ALL IGNITION SYSTEMS 6 1 DESCRIPTION Incorrect polarity in the primary or secondary circuit can result in a greater voltage require ment to fire the spark plugs and may cause the engine to misfire under load or at high speed This test checks for correct polarity in the entire ignition circuit CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 6 2 HOOK UP PROCEDURE Refer to Figure 6 1A B or C The scope controls and cables are numbered in Figure 6 14 B or C as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads 27d sockets are color coded and keyed to ensure proper 2okup The scope items are described in detail in Chapter igure 2 1 Table 2 1 Engine Off Do not start the engine before hookup POWER LEAD Connection Make the following conn
39. CTION SELECTOR 3 is set to the DISTRIBUTOR PATTERN position B Crank Engine Have a helper crank the engine C Check Pattern Compare the pattern displayed on the scope while the engine is cranking with the patterns il lustrated below in Test Results Figures 17 5 and 17 6 The pattern displayed on the scope screen should match the normal pattern illustrated in Figure 17 5 While the engine is cranking gently wiggle or flex the pick up coil wires their full length while observing the scope display The pattern shown in Figure 17 5 should remain constant If there is any sign of erratic operation check the pick up coil wires for in sulation nicks cuts or wear and check the terminals for good connections D Reconnect Remove test leads reconnect all wires and connectors 17 8 TEST RESULTS A Normal Pattern dE DEE MAGNETIC PICK UP COIL TEST Normal Pattern Chrysler FIGURE 17 5 B Unsatisfactory Pattern A line with no vertical amplitude is an unsatisfactory pattern If an unsatisfactory pattern exists the magnetic pick up coil is not functioning properly 1 Check the pick up coil with an ohmmeter There should be no reading infinity from either wire to ground and the resistance across the coil should be 150 900 ohms NO AMPLITUDE 7 MAGNETIC PICK UP COIL TEST Unsatisfactory Pattern Chrysler FIGURE 17 6 SECTION Ill FORD SSI DSI DSII Systems 17 9 DESCRIPTION Some electronic ignitio
40. H CONTROL 6 as described in each test to select and locate a waveform pattern on the oscilloscope screen for test measurement observation and interpretation A 50 KV Coil This function displays the complete series of spark ignition voltages for all the cylinders of the test ve hicle as illustrated in Figure 4 1 When properly adjusted the waveform pattern provides the technician with an overall view of all the spark ignitions in their proper firing order By comparison and measurement the technician can determine and locate an abnormal ignition condition in one or all of the cylinders This is a calibrated scale for measuring maximum available high voltage delivered by the ignition coil when one spark plug wire is disconnected WW WS SE WE de hhh EE 50 KV COIL Pattern Display FIGURE 4 1 KV Spark This is a calibrated voltage scale and yoltage required to fire each of the spark plugs e as illustrated in Figure 4 4 When properly asus Caen provides the technician with an overall view of aii tne spark voltages in their proper firing order This pattern appears as four six or eight vertical lines according to the number of cylinders in the test engine The height of these lines represents the peak ema 2 ta U0 Pr ny a v gi ID V ro E o H amp gt 3 EG ee amplitude of the voltage By comparison and measure ment the technician can determine and locate an abnor mal
41. HE VEHICLE SERVICE MANUAL FOR SPECIFIC TUNE UP INFORMATION AND TEST PRO CEDURES ALWAYS FOLLOW THE MANUFACTURER S SPECIFICATIONS AND TEST PROCEDURES FOR ADJUSTING DWELL ANGLE IDLE SPEED AND CHARGING SYSTEM OUTPUT ESPECIALLY VEHI CLES WITH MODERN ELECTRONIC IGNITION AND EMISSION CONTROLS DO NOT ATTEMPT TO SER VICE A VEHICLE WITHOUT THE MANUFACTURER S INSTRUCTIONS AND SPECIFICATIONS 1 2 VEHICLE MANUAL SOURCES FOR SERVICE INFORMATION The following is a list of publishers who have service manuals for your specific vehicle at nominal cost Write to them for availability and prices specifying the make style and model year of your vehicle American Motors Corporation Buick OTHER SOURCES Myriad Tuar Company NONFACTORY 8835 General Drive Post Office Box 354 Plymouth Township Flint Michigan 48501 Domestic and Import Cars Michigan 48170 Oldsmobile Chilton Book Company Chrysler Corporation Lansing Lithographers Chilton Way Dyment Distribution Service Post Office Box 23188 Radnor PA 19089 Service Publication Lansing Michigan 48909 20026 Progress Drive Cordura Publications Strongsville Ohio 44136 Cadillac Chevrolet Pontiac Mitchell Manuals Inc Helm Incorporated Post Office Box 26260 Ford Publication Department Post Office Box 07130 San Diego CA 92126 Helm Incorporated Detroit Michigan 48207 Post Office Box 07150 Motor s Auto Repair Manual Detroit Michigan 48207 Hearst Company 250 W 55th Street New York N Y 10019 3
42. LOAD TEST Hook Up GM HEI NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or in completely closed clamps may cause mistrigger ing and or faulty calibration of scope patterns NOTE In most HEI systems the coil is mounted internally and requires the use of the HEI PATTERN CAPA CITIVE PICK UP 10 for this test The following paragraphs provide hook up instructions for both externally and internally mounted coils Be sure to use the correct pick up for the system being tested C CAPACITIVE PICK UP 9 or GM HEI PATTERN CA PACITIVE PICK UP 10 Connections 1 CAPACITIVE PICK UP 9 Use the CAPACITIVE PICK UP 9 for HEI and TFI systems with the ignition coil mounted externally a Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope b Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire 2 HEI PATTERN CAPACITIVE PICK UP 10 Use the HEI PATTERN CAPACITIVE PICK UP 10 for HEI systems with the ignition coil mounted internally in side the distributor cap a Scope Plug the yellow HEI PATTERN CAPACI TIVE PICK UP 10 connector into the yellow socket on the back of the scope b Vehicle Clip the HEl PATTERN CAPACITIVE PICK UP 10 onto the top of the distributor cap D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK
43. N CAPACITIVE PICK UP 10 connector into the yellow socket on the back of the scope b Vehicle Clip the HEl PATTERN CAPACITIVE PICK UP 10 onto the top of the distributor cap D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to DISTRIBUTOR PATTERN position F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Speed Adjust engine speed as required to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2
44. O A SECTION Il GM HEI FORD TEL TELL TFI IV Systems 7 5 DESCRIPTION For any ignition system to function properly the ignition coil must be able to produce a high secondary voltage Failure of the ignition coil to produce adequate voltage may cause the engine to misfire under load or at high speed The maximum secondary voltage produced by an ignition coil can be measured in this test to ensure adequate voltage CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 7 6 HOOK UP PROCEDURE Refer to Figure 7 4A or B The scope controls and cables are numbered in Figure 7 4 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure prope hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black soc
45. PACITIVE PICK UP 9 connector into the yellow socket on the back of the scope Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire HEI PATTERN CAPACITIVE PICK UP 10 Use the HEI PATTERN CAPACITIVE PICK UP 10 for HEI systems with the ignition coil mounted internally in side the distributor cap Figure 7 4B a Scope Plug the yellow HEI PATTERN CAPACI TIVE PICK UP 10 connector into the yellow socket on the back of the scope b Vehicle Clip the HEl PATTERN CAPACITIVE PICK UP 10 onto the top of the distributor cap D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle a Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON the switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn b scope OFF Reconnect scope cables to the battery as expla
46. SEARS owners A eer 228 manual eeh NO SEARS CRAFTSMAN DIAGNOSTIC OSCILLOSCOPE Caution Read Rules For s OPERATING INSTRUCTIONS Safe Operation and Complete Operating Test Procedures Carefully REPAIR PARTS SEARS ROEBUCK AND CO U S A CHICAGO ILLINOIS 60684 PRINTED IN U S A 2 176202 TABLE OF CONTENTS Title RULES FOR SAFE AUTOMOTIVE TESTING dui ERA AGA RA E WARRANTY rata AR AAA As CHAPTER 1 INTRODUCTION 1 1 INTRODUCTION ona AA eevee ea aeons 1 2 VEHICLE MANUAL ona pears e D AA A ou owe E 1 3 OSCILLOSCOPE MANUAL o 2 sna 55 4 aa tin dea Ee lbs 1 4 TEST SELECTION FOR VEHICLE cias ie Ne e AE da des 1 5 SAFETY INFORMATION lada 1 6 GENERAL INFORMATION conspira iS A Aa A OSciloscope Lesing an OS tai EA B Oscilloscope e CG C Oscilloscope EEN CHAPTER 2 OSCILLOSCOPE CONTROLS CONNECTIONS AND ACCESSORIES 2 1 DESCRIPTION catas ENS nee ees awe SARS TREES ae we ee weet ae CHAPTER 3 TEST DESCRIPTIONS 3 1 SPARK POLARITY TEST o a Mee erate dis 3 2 MAXIMUM COIL OUTPUT AVAILABLE VOLTAGE TEST 0 0 0c co 3 3 SECONDARY INSULATION TES Tia iento bal deg RENA eae RES 3 4 SPARK VOLTAGE UNDER LOAD TEST siria aw tied seed ea 3 5 DWELL amp VARIATION IN DWELL TEST Sia A AA Se 3 6 COIL CONDENSER TEST o dias ri as 3 7 POINT AC TON TEST EE 3 8 SECONDARY RESISTANCE TEST ia AR ASS AS 3 9 COIL OUTPUT AT CRANKING SPEED TEST 3 10 ROTOR GAP TEST ans IE AAN dead 3 11 ALTERNA TOR TEST me
47. TFI TFI I and IV FIGURE 15 4A INTEGRAL COIL GM HEI FIGURE 15 4B ROTOR GAP TEST Hook Up HEI 51 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or in completely closed clamps may cause mistrigger ing and or faulty calibration of scope patterns In some HEI systems the coil is mounted internally and requires the use of the HEI PATTERN CAPA CITIVE PICK UP 10 for this test The following paragraphs provide hook up instructions for both externally and internally mounted coils Be sure to use the correct pick up for the system being tested NOTE C CAPACITIVE PICK UP 9 or GM HEI PATTERN CA PACITIVE PICK UP 10 Connections 1 CAPACITIVE PICK UP 9 Use the CAPACITIVE PICK UP 9 for HEI and TFI systems with the ignition coil mounted externally a Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope b Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire HEI PATTERN CAPACITIVE PICK UP 10 Use the HEI PATTERN CAPACITIVE PICK UP 10 for HEI systems with the ignition coil mounted internally in side the dist
48. The point close signal repre sents the closing of the points and the build up of the magnetic field in the coil primary by the flow of current through the coil This signal displays a series of several diminishing oscillations The components which affect this signal are the ignition points con denser and the coil Abnormal conditions with any of these components will affect the appearance of the oscillations in this section of the pattern Point Open Signal The point open signal represents the opening of the points and the end of the dwell sec tion This signal appears as an abrupt 90 degree up ward angle of the pattern line The components which affect this signal are the coil condenser and the igni tion points Abnormal conditions with these compon ents will affect the abruptness of the upward angle Dwell Section Length The length of the dwell sec tion from the point close signal through the point open signal is affected by the dwell setting CHAPTER 5 TYPES OF IGNITION SYSTEMS 5 1 INTRODUCTION To perform any oscilloscope test the technician must have the ability to select the correct tests for the specific vehicle being tested Prior to the early 1970 s breaker point ignition systems were the automobile in dustry s standard For these systems the oscilloscope hook up procedures test procedures test results and oscillo scope waveform patterns are identical with a few minor ex ceptions In 1973 Chrysler Corp
49. UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 25 KV SPARK POSITION F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Speed Adjust engine speed as required to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark pl
50. aa co teat ec eile A A ai 11 3 TEST PROCEDURE a Cor a aia eos Se a BE eee ea tbe eM ents 11 4 TEST RESULTS lt td hae a ASS Bee ea ewe eins A A lt Normal Pavey eran RI A ANS AAA Sate aes B WASAUSTACIOlY Pattern ico sa a LOPS CHAPTER 12 POINT ACTION TEST BPI 12 1 DESCRIPTION o A RA OEE one he WANG Satan oh ee 12 2 HOOK UP PROCEDURE vastas AA ARA Rae 12 3 TEST PROCEDURE unitaria da ee ewes a 12 4 TEST RESULTS SS SS tere ae Re A TNO Mal Pattern iaa aa edie a Deen ooo iad aa tua EE E stinsatisiaGtory Pater uri ad ns oa tie Aneel a ladies CHAPTER 13 SECONDARY RESISTANCE TEST ALL IGNITION SYSTEMS 13 1 DESCRIPTION ias dt iS Bere bee cea ate ASA ITA Poa ee eas 13 2 HOOK UP PROCEDURE 2 dais la E 13 3 TES PROCEDURE Ee ee A AS A ts 13 4 RH ET EE AE A Red TO ARA de OE A RS IES As Normal En tica Ed a A beens Ao EE B Unsatistactory Pattern sl A eg Ek een A CHAPTER 14 COIL OUTPUT AT CRANKING SPEED TEST Section 1 Breaker Point BPI Ignition Systems 14 1 DESCRIPTION EEN 14 2 HOOK UP ee E EE 14 3 TEST PROCEDURE cui aa a il dd des 14 4 MEST RESULTS iia cee orca E E pis ees A NA A Normal E EE tes A B Unsatisfactory Pattern Gene E ge ta Aa e e enee e CHAPTER 15 ROTOR GAP TEST Section Breaker Point All Chrylser Electronic Ford Solid State and Dura Spark and Prestolite BID Ignition Systems 15 1 DESCRIPTION ad nated A hate Sete maw a ee ml ae 15 2 HOOK UP PROCEDURE cscs ee data aaa IR oh
51. able 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 9 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the 25 KV SPARK VOLTAGE POSITION B Accelerate Engine Snap accelerate the engine by quickly depressing the accelerator pedal and then releas ing it Allow the engine to return to idle between accelera tions Do not hold the accelerator pedal down A snap ac celeration is a very rapid push release of the accelerator pedal C Check Pattern During snap acceleration compare the voltage pattern displayed on the scope with the patterns il lustrated below in Test Results Figures 9 2 and 9 3 D Engine Off Turn vehicle engine off 9 4 TEST RESULTS A Normal Pattern All spark voltages should be fairly uniform and increase slightly 1 2 KV during snap accelera tion Engines designed to operate with a large rot
52. al alternator pattern will display consistent smooth oscillations as shown in Figure 16 2 Evenly spaced ignition spikes which may appear throughout the pattern should be disregarded B Unsatisfactory Patterns te ALTERNATOR TEST Unsatisfactory Pattern FIGURE 16 3 1 Open field or defective regulator Fig 16 3 ALTERNATOR TEST Unsatisfactory Pattern FIGURE 16 4 2 Shorted diode Fig 16 4 ALTERNATOR TEST Unsatisfactory Pattern FIGURE 16 5 3 Open diode Fig 16 5 ALTERNATOR TEST Unsatisfactory Pattern FIGURE 16 6 4 Shorted winding Fig 16 6 ALTERNATOR TEST Unsatisfactory Pattern FIGURE 16 7 5 Open winding or two open diodes one phase Fig 16 7 ALTERNATOR TEST Unsatistactory Pattern FIGURE 16 8 6 One shorted diode and one open diode opposite polarity Fig 16 8 Li ALTERNATOR TEST Unsatistactory Pattern FIGURE 16 9 7 One shorted diode and one open diode same polarity Fig 16 9 Abnormal Pattern Any pattern obtained other than that shown in Figure 16 2 should be considered abnormal Fur ther diagnosis on the charging system should be done in ac cordance with your vehicle service manual CHAPTER 17 MAGNETIC PICK UP COIL TEST SECTION I GM HEI System 17 1 DESCRIPTION Some electronic ignition systems use a magnetic pickup coil and reluctor assembly in place of contact points Faults in operation of this assembly may be determined by this test Thi
53. and close properly for each spark plug firing This test checks for proper action of the breaker points Refer to Chapter 12 10 3 8 SECONDARY RESISTANCE TEST A limited amount of resistance is built into the secondary circuit to extend the spark plug electrode life and to minimize interference with radio and television reception Excessive resistance dissipates the energy otherwise needed to maintain good ignition during high speed operation This test checks for excessive secondary resistance Refer to Chapter 13 3 9 COIL OUTPUT AT CRANKING SPEED TEST A fault in the primary circuit or a defective coil may cause an en gine to be hard to start or fail to start This test determines if these systems are the cause of a starting problem Refer to Chapter 14 3 10 ROTOR GAP TEST Adequate voltage is required to properly arc the gap between the rotor and the distribu tor cap terminals This test measures the voltage of the arc to determine possible faults in this circuit Refer to Chapter 15 3 11 ALTERNATOR TEST Fauits in alternator operation may be determined by analysis of the scope patterns pro duced in this test Refer to Chapter 16 3 12 MAGNETIC PICK UP COIL TEST Some electronic ignition systems use a magnetic pickup in place of contact points Faults in operation of the magnetic pickup may be determined by this test Refer to Chapter 17 CHAPTER 4 BASIC SCOPE PATTERNS 4 1 INTRODUCTION A The ignition system
54. ary gap spark plugs 2 If all voltages are uniform but low check for a Closely gapped spark plugs b Advanced ignition timing SPARK VOLTAGE UNDER LOAD TEST c Overall low compression Normal Pattern HEI and TFI d Rich fuel mixture FIGURE 9 5 3 Ifone or more voltages are high check for a Worn or widely gapped spark plug B Unsatisfactory Pattern A fault exists if the spark volt b Open spark plug cable ages are not uniform or if the voltage increase is either too c Cocked or worn distributor cap small or too great d Unbalanced fuel mixture 2 or 4 barrel carburetor only 4 Ifone or more voltages are low check for a Fouled or closely gapped spark plug b Shorted spark plug cable or cracked insulator c Low compression cylinder d Unbalanced fuel mixture 2 or 4 barrel carburetor only Spark voltage high spark voltage low SPARK PLUG VOLTAGE TEST Unsatisfactory Pattern HE and TFI FIGURE 9 6 CHAPTER 10 DWELL AND VARIATION IN DWELL TEST BPI GM HEI 10 1 DESCRIPTION FOR BPI For GM HEI see 10 5 Dwell is the period of time that the distributor points are clos ed during each cylinder ignition firing cycle This test measures the variation of dwell among all the cylinders to determine specific faults in the distributor Refer to Chapter 10 CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 10 2 HOOK UP PROCEDURE Refer to Figure 10 1 The
55. ayed on the scope screen should match the normal pattern illustrated in Fig ure 7 8 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire 7 12 TEST RESULTS A Normal Pattern The secondary voltage available for the disconnected spark plug should be greater than 24 KV for the SSI system or 28 KV for the DS systems as read on the 50 Kilovolt scale If a satisfactory pattern exists both the primary and secondary circuits are operating normally 24 KV for SSI or 28 KV for DS systems minimum MAXIMUM COIL OUTPUT TEST Normal Pattern SSI DS Systems FIGURE 7 8 B Unsatisfactory Pattern An unsatisfactory pattern shows a maximum available voltage of less than 24 KV on the SSI System or 28 KV on the DS Systems as displayed on the 50 Kilovolt scale Less than 24 KV for SSI or 28 KV for DS systems MAXIMUM COIL OUTPUT TEST Unsatisfactory Pattern SSI DS Systems FIGURE 7 9 If an unsatisfactory pattern exists check for a b Defective coil wire C d Excessive resistance in primary circuit reducing e f Defective coil Low battery voltage input to ignition coil Defective secondary insulation Defective ignition module CHAPTER 8 SECONDARY INSULATION TEST SECTION I BPI System 8 1 DESCRIPTION The secondary ignition circuit is the path of voltage from the coil to the gap of the spark plugs electrodes This test checks the secondary ignition circuit for
56. bracket as shown in Figure 8 1 SECONDARY INSULATION TEST Hook Up BPI FIGURE 8 1 CAUTION When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICk UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns 25 C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket n the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After th
57. c ondary circuit will cause voltage to arc to ground instead of to the corresponding spark plug and cylinder This re sults in the misfire of the spark plug CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 8 14 HOOK UP PROCEDURE Refer to figure 8 10 The scope controls and cables are numbered in figure 8 10 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 figure 2 1 table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connection Make the following connections 31 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive battery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Fi
58. calibra tion of scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 25 KV SPARK POSITION F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unst
59. car to run with a plug not firing overheating will result 7 2 HOOK UP PROCEDURE Refer to figure 7 1 The scope controls and cables are numbered in figure 7 1 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 figure 2 1 table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive battery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 7 1 F MAXIMUM COIL OUTPUT TEST Hook Up BPI EIS EIS MMC EIS HALL BID FIGURE 7 1 19 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty
60. circuit and the igni tion coil are functioning properly the coil output voltage will extend at least 20 KV above the zero line Use your engine analyzer and vehicle service manual to trouble shoot these areas Qa oOo a Normal Voltage at least 20 KV ZO COIL OUTPUT AT CRANKING SPEED TEST Normal Pattern FIGURE 14 2 B Unsatisfctory Pattern When the coil output voltage is less than 20 KV above the zero line the pattern is unsat isfactory Abnormal Voltage below 20 KV o COIL OUTPUT AT CRANKING SPEED TEST Unsatisfactory Pattern FIGURE 14 3 48 CHAPTER 15 ROTOR GAP TEST SECTION I BPI ALL CHRYSLER ELECTRONIC FORD SSI DS SYSTEMS PRESTOLITE BID SYSTEMS 15 1 DESCRIPTION Adequate voltage is required to properly arc the gap between the rotor and the distributor cap terminals This test measures the voltage of the arc to determine possible faults in this circuit CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 15 2 HOOK UP PROCEDURE Refer to Figure 15 1 The scope controls and cables are numbered in Figure
61. clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 15 7 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 25 KV SPARK POSITION CAUTION On HEI systems do not disconnect spark plug wires at the distributor during testing CAUTION Selection of spark plug wires to be disconnected is critical on Ford Electronic Ignition Systems Unless properly selected damage to the ignition system electronics may result DO NOT DISCONNECT V 8 engines No 1 or No 8 spark plug wire V 6 engines No 1 or No 4 spark plug wire l 6 engines No 3 or No 5 spark plug wire 4 Cylinder engines No 1 or No 3 spark plug wire C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any properly selected spark plug wire with boot at the spark plug end except the wire leading to t
62. connections or leaks occurring in vacuum lines and vacuum operated accessories Loose manifold bolts Broken or damaged intake manifold or carburetor gaskets Crack in manifold Warped or damaged manifold contacting surface Incorrect ignition timing Spark plug malfunction Ignition wires open or leaking to ground Defective PCV system Defective ignition condenser Spark advanced too far Defective ignition switch Defective valves LACK OF POWER or HIGH SPEED PERFORMANCE Insufficient or unequal engine cylinder compression Improper ignition timing Inoperative manifold heater valve valve held in closed position Improper carburetion Restricted carburetor air inlet resulting from Dirty air cleaner Choke valve not completely opening Throttle linkage not properly adjusted and carburetor throttle valve not completely opening Carburetor accelerating pump not functioning properly Improper fuel pump operation Partially restricted or clogged exhaust pipe muffler or tail pipe Excessive engine temperatures Preignition Excessive engine friction resulting from Inadequate internal clearances bearings and pistons Use of extreme pressure piston rings Clutch slippage Excessive rolling resistance resulting from Dragging brakes Tight wheel pinion differential or transmission bearings Misalignment in power transmitting units Misalignment of rear axle Underinflated tires Incor
63. connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion POINT ACTION TEST Hook Up BPI FIGURE 12 1 NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns 43 C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to DISTRIBUTOR PATTERN position F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horiz
64. ctions 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 16 1 2 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns 53 ae ALTERNAT OR TEST Hook Up FIGURE 16 1 C INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle a Clamp the INDUCTIVE PICK UP 8 onto the No 1 spark plug wire Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires WARNING The positive stud of the alternator is live use care when making this connection so that you do not cre ate a spark which could cause an explosion b Clip the blue alligator clip of the ALTERNATOR LEAD 1
65. ctor into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 25 KV superimposed F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Speed Adjust engine speed as required to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Slide the capacitive pick up 9 along the c
66. cur when the scope is used in conjunction with some automobile analyzers Disconnect the Analyzer to see if the pat tern returns to normal before replacing the coil Lack of oscillations COIL CONDENSER TEST Unsatisfactory Pattern BP FIGURE 11 4 42 CHAPTER 12 POINT ACTION TEST BPI 12 1 DESCRIPTION It is important that the points open and close properly for each spark plug firing This test checks for proper action of the breaker points CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 12 2 HOOK UP PROCEDURE Refer to Figure 12 1 The scope controls and cables are numbered in Figure 12 1 asa reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 12 1 2 WARNING When making electrical test
67. d by an ignition coil can be measured in this test to ensure ade quate voltage Refer to Chapter 7 3 3 SECONDARY INSULATION TEST The secondary ignition circuit is the path for voltage from the coil to the gap of the spark plugs electrodes This test checks the sec ondary ignition circuit for proper insulation A break in the insulation of the secondary circuit will cause voltage to arc to ground instead of to the corresponding spark plug and cylinder This results in the misfire of the spark plug Refer to Chapter 8 3 4 SPARK VOLTAGE UNDER LOAD TEST The spark voltage of all cylinders should be fairly uniform and rise slightly when the engine is snap accelerated This test measures and compares the voltage requirements of each cylinder in an engine under load to determine if any faults are present Refer to Chapter 9 3 5 DWELL AND VARIATION IN DWELL TEST Dwell is the period that the distributor points are closed during each cylinder ignition firing cycle This test measures the varia tion of dwell among all the cylinders to determine specific faults in the distributor Refer to Chapter 10 3 6 COIL CONDENSER TEST Energy remaining in the coil after the spark plug has fired must be dissipated prop erly to protect the points This test measures the dissipa tion of the voltage and determines if there is a fault in the coil or the condenser Refer to Chapter 11 3 7 POINT ACTION TEST It is important that the points open
68. e CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 25 KV SPARK position F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Speed Adjust engine speed as required to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor
69. e Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen D Som edie A NOTE A break with the battery will turn scope OFF Recon nect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 8 3 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any spark plug wire with boot at the spark plug end
70. e disconnected is critical on Ford Electronic Ignition Systems Unless properly selected damage to the ignition system electronics may result DO NOT DISCONNECT No 1 or No 8 spark plug wire No 1 or No 4 spark plug wire No 3 or No 5 spark plug wire V 8 engines V 6 engines I 6 engines 4 Cylinder engines No 1 or No 3 spark plug wire C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any properly selected spark plug wire with boot at the spark plug end except the wire leading to the No 1 spark plug Do not allow this wire to arc to ground The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 8 6 D D Engine On Start vehicle engine E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results figures 8 5 and 8 6 The pattern displayed on the scope screen should match the normal pattern illustrated in Fig ure 8 5 The pattern illustrated is the GM HEI system Oscillation detail on the TFI system may be different Refer to chapter 5 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire H Test Remaining Spark Plug Wires Repeat the test procedure with each spark plug wire except the wire lead ing to the No 1 spark plug See next step Remember not to disconnect wires indicated after Step 8 7B Make a note of which cylinder patterns are normal and whic
71. e ground C PICK UP COIL TEST LEAD 12 Connections 1 Scope Plug the yellow PICK UP COIL TEST LEAD 12 connector into the yellow socket on the back of the scope 2 Vehicle a Remove distributor cap and rotor If necessary for clearance on V 6 and V 8 engines also remove distributor BAT lead and module connector at the distributor cap To avoid damage to the rotor and high tension output contact in the cap pull the cap straight up at least one inch before tipping to remove b Disconnect the white and the green wires from the pick up coil side of the electronic module and connect the PICK UP COIL TEST LEAD clips to the wires as shown in Figure 17 1 D Select Function Rotate FUNCTION SELECTOR 3 to DISTRIBUTOR PATTERN position E Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop F Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH 17 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the DISTRIBUTOR PATTERN position B Crank Engine Have a helper crank the engine C Check Pattern
72. ections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 6 1 A B or C J ie WARNING hen making electrical test connections to the ve cle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion 7 NORICAL COIL SYSTEMS FIGURE 6 1A SPARK POLARITY TEST Hook Up XQ TA a E CORE COIL SYSTEMS GM HEI FORD TFI TEL and IV FIGURE 6 1B INTEGRAL COIL GM HEI FIGURE 6 1C SPARK POLARITY TEST Hook Up NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns NOTE In most HEI systems the coil is mounted inside the distributor and requires the use of the HEI PATTERN CAPACITIVE PICK UP 10 for this test The following paragraphs provide hook up instructions for both ex ternally and internally mounted coils Be sure to use the correct pick up for the system being tested C CAPACITIVE PICK
73. ectronic ignition systems will vary as shown in Chap ter 5 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire 7 4 TEST RESULTS A Normal Pattern The secondary voltage available for the disconnected spark plug should be greater than 20 KV for Breaker Point Systems or approximately 24 26 KV for Electronic Ignition Systems as read on the 50 Kilovolt scale If a satisfactory pattern exists both the primary and secon dary circuits are operating normally B Unsatisfactory Pattern An unsatisfactory pattern shows a maximum available voltage of less than 20 KV on the Breaker Point System or approximately 24 26 KV on the electronic systems as displayed on the Kilovolt Scale 20KV for BPI or 24 26KV for electronic systems minimum MAXIMUM COIL OUTPUT TEST Normal Pattern BPI FIGURE 7 2 Less than 20KV for BPI or less than 24 26 KV for electronic systems MAXIMUM COIL OUTPUT TEST Unsatisfactory Pattern BPI FIGURE 7 3 If an unsatisfactory pattern exists check for a Defective coil b Defective coil wire c Low battery voltage d Dwell much lower than specified Does not apply to electronic ignition systems Excessive resistance in primary circuit reducing input to ignition coil Defective secondary insulation on ignition wires Defective condenser Defective rotor and or distributor cap Defective ignition module Electronic ignition systems only O T
74. ee The following nine illustrations show this secondary oscilla tion detail clearly Pick the illustration which matches your vehicles s ignition system and study it carefully It is a good representation of what your scope should show you in this portion of the pattern when the ignition system is function ing properly The illustrations shown are most accurate with the engine running between 900 1400 RPM PRESTOLITE BID Breakerless Inductive Discharge FIGURE 5 1 VW CHRYSLER EIS Electronic Ignition System FIGURE 5 2 CHRYSLER ELB amp ESC Electronic Lean Burn 4 Electronic Spark Control FIGURE 5 3 l CHRYSLER EIS HALL Electronic Ignition System amp Electronic Spark Control FIGURE 5 4 CHRYSLER EIS MMC Electronic Ignition System Mitsubishi Motor Corporation FIGURE 5 5 FORD SSI DSII amp DS il Solid State Ignition Dura Spark I amp 111 FIGURE 5 6 FORD DS DURA SPARK California Only FIGURE 5 7 FORD TFI TFI I TFI IV Thick Film Integrated Ignition FIGURE 5 8 DELCO REMY GM HEI High Energy Ignition FIGURE 5 9 5 4 Ignition System Abbreviations Please note that the following abbreviations regarding ig nition systems will be used extensively throughout this manual 1 BPI Breaker Point Ignition System 2 EIS Chrysler Electronic Ignition System Domestic 8 cylinder engines 3 EIS HALL Chrysler Electronic Ignition System and Electre Spark Control HALL EFFE
75. een C Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results figures 10 2 and 10 3 Read the variation in dwell on the appropriate 4 6 or 8 cylinder scale of POINT DWELL IN DEGREES D Repeat steps B and C at 1500 RPM E Return the engine to idle F Engine Off Turn vehicle engine off 10 4 TEST RESULTS A Normal Pattern The variation in dwell among all the cylinders as seen on the superimposed pattern display should be no greater than three degrees on the appropriate 4 6 or 8 cylinder scale DWELL AND VARIATION IN DWELL TEST Normal Pattern BPI FIGURE 10 2 B Unsatisfactory Pattern If the variation in dwell among all the cylinders is greater than three degrees a fault in the distributor may exist 40 l 1 SET LINE sl VARIATION IN DWELL 1 4 CYLINDER 8 CYLINDER 30 15 35 30 25 20 6 CYLINDER POINT DWEL IN DEGREES DWELL AND VARIATION IN DWELL TEST Unsatisfactory Pattern BPI FIGURE 10 3 If variation in dwell is greater than three degrees on the appropriate cylinder scale then check for a Worn lobes in the distributor cam b Bent distributor shaft c Worn distributor shaft bushings 10 5 GM HEI No specific readings are given by GM for their HEI system however it is normal for dwell to vary with engine speed on this system A HOOK UP PROCEDURE Use the same hook up and scope co
76. een tested satisfactorily Disconnect and test the No 1 spark plug wire 8 16 TEST RESULTS A Normal Pattern The downspike of the pattern for the disconnected spark plug should be approximately one third as long as the upward spike of the pattern as illustrated in Figure 8 11 If this pattern is displayed the secondary insula tion is satisfactory Negative _ Spike SECONDARY INSULATION TEST Normal Pattern SSI DS Systems FIGURE 8 11 B Unsatistactory Pattern If the pattern displayed shows a short or no donwspike for the disconnected spark plug as illustrated in Figure 8 12 there is a secondary insulation problem Short or No Negative Spike SECONDARY INSULATION TEST Unsatisfactory Pattem SSI DS FIGURE 8 12 1 If an unsatisfactory pattern exists for all spark plugs cylinders check for a Cracked or carbon tracking in the coil tower b Defective coil wire c Cracked or carbon tracking in the rotor d Cracked or carbon tracking in the center tower of distributor cap If one or more but not all spark plugs cylinders test unsatisfactorily check for a Cracked or carbon tracking in the distributor cap towers b Defective spark plug wires Refer to step three be low for instructions on testing individual spark plug wires Defective Spark Plug Wire Test If the above test re sults indicate faulty spark plug wires perform the fol lowing procedure to determine which spark plug wi
77. er hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 11 1 2 COIL CONDENSER TEST Hook Up BPI FIGURE 11 1 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns E K C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle
78. es not require a separate battery adapter and shunt resistor for alternator testing The alternator signal is sensed at the alternator output ter minal or at the positive battery post The most outstanding features of this scope are the simplicity of the front panel controls and the ease of testing provided by the test procedures 8 CHAPTER 2 OSCILLOSCOPE CONTROLS CONNECTIONS AND ACCESSORIES DESCRIPTION The Model 21056 Oscilloscope has clearly ce on the right as shown in Figure 2 1 The screen gt 242 2 7 ear sharp contrast display of patterns with a vertical 2 staeon the left and horizontal dwell scale for 4 6 and 8 oer clesacrossthe bottom The connector sockets on the 12 20 or coded and keyed to their corresponding connector 2 Tirrols connections and accessories are illustrated in ro and described in Table 2 1 Table 2 1 Oscilloscope Controls Connections and Accessories 7 ER ON SWITCH 1 ectarily pressed to turn the oscilloscope ON after the ead has been connected to 12 volts The POWER dl ICH illuminates to indicate power on OWER OFF SWITCH 2 entarily pressed to turn the oscilloscope OFF before scocomnecting power lead from 12 volts If a power supply 22 s accidentally disconnected the scope must be turned Z again after the lead has been reconnected INCTION SELECTOR 5823 to select the proper ignition or alternator pattern re gt 72d for each test ERTICAL POSITION
79. essive engine temperature APPENDIX B REPLACEMENT PARTS podido FIGURE 19 1 REPLACEMENT PARTS DIAGNOSTIC OSCILLOSCOPE MODEL 161 21056 Description 1 450 143 Function Selector Knob w skirt 2 450 142 Control Knob 3 38 827 Cable Magnetic Pick up Coil Test 4 38 830 Capacitive Pick up HEI 5 38 829 Capacitive Pick up External Coil 6 38 828 Inductive Clamp Alternator Cable 7 38 826 Cable Power 8 450 141 Plier Insulated Fiber 9 2 176202 Manual Owners Not illustrated 10 1000 1153 Cable Kit contains key no s 3 8 inclusive TABLE 19 1 REPLACEMENT PARTS LIST All parts listed may be ordered from any Sears Roebuck and Company store or service center WHEN ORDERING REPAIR PARTS ALWAYS GIVE THE FOLLOWING INFORMATION 1 PART NUMBER 3 PART DESCRIPTION 2 MODEL NUMBER 161 21056 4 NAME OF ITEM DIAGNOSTIC OSCILLOSCOPE If the parts you need are not stocked locally your order will be electronically transmitted to a Sears Repair Parts Distribution Center for expedited handling 63 SEARS SEARS CRAFTSMAN owners manual DIAGNOSTIC OSCILLOSCOPE Now that you have purchased your Diagnostic Oscilloscope with Induc tive Pickup should a need ever exist for repair parts or service simply MODEL NO contact any Sears Service Center and most Sears Roebuck and Co stores Be sure to provide all pert
80. g wire 30 that has already been tested satisfactorily Disconnect and test the No 1 spark plug wire 8 12 TEST RESULTS A Normal Pattern The normal basic scope pattern of the spark plugs for the Chrysler Electronic Ignition System 6 and 8 cylinder domestic only does not have a coil con denser action section Refer to Figure 8 8 Refer to Chapter 5 for oscillation detail on all remaining Chrysler Systems Under the secondary insulation test the downspike of the pattern for the disconnected spark plug should be approx imately one third as long as the upward spike of the pattern as illustrated in Figure 8 8 If this pattern is displayed the secondary insulation is satisfactory PA Negative E Spike SECONDARY INSULATION TEST Normal Pattern ElS l FIGURE 8 8 B Unsatisfactory Pattern If the pattern displayed shows a short or no downspike for the disconnected spark plug as illustrated in Figure 8 9 there is a secondary insulation problem Short or No Negative Spike SECONDARY INSULATION TEST Unsatisfactory Pattern EIS FIGURE 8 9 1 If an unsatisfactory pattern exists for all spark plugs cylinders check for a Cracked or carbon tracking of the coil tower b Defective coil wire c Cracked or carbon tracking of the rotor d Cracked center tower or carbon tracking of the distributor cap If one or more but not all spark plugs cylinders test unsatisfactorily check for a Cracked or carb
81. ge of the arc to determine possible faults in this circuit CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily F cl CAUTION On cars equipped with a catalytic converter recor nect spark plug wire as quickly as possible to avc c damage to converter Do not allow car to rur oi plug not firing overheating will result A a 15 6 HOOK UP PROCEDURE Refer to Figures 15 4A and B The scope controls and cables are numbered in Figures 15 4A and B as a reference for hookup This procedure ex plains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure pro per hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as show in Figure 15 4 A or B 2 E CORE COIL SYSTEMS GM HEI FORD
82. gnition BPI Breaker Point Ignition BPI 6 s amp V 8 s only 4 s BPI 6 s amp V 8 s only All except 2 8 L V 6 2 8 LV 6 1973 1983 1978 1984 Electronic Ignition System EIS Electronic Ignition System EIS HALL Electronic Spark Control System 6 s amp V 8 s only Hall effect distributor domestic 4 cyl 1981 1984 Electronic Ignition System Mitsubishi EIS MMC 376 1978 Electronic Lean Burn System ELB gt En tae Electronic Spark Control System ESC 1981 1984 Electronic Fuel Control System EFCS 2 6 L 4cyl only Selected 6 s and V 8 s only 6 s 8 V 8 s only 6 s amp V B s orty 13 Table 5 1 Ignition System Identification continued Manufacturer Year Ignition System Qualification FORD MOTOR COMPANY Thru 1974 1974 1976 Breaker Point Ignition BPI Motorcraft Solid State Ignition SSI 1977 1984 Dura Spark II DS II 1980 1984 1982 1984 Dura Spark Ill DS III Thick Film Ignition TFI l Most Calif only Check Vehicle Service Manual Check Vehicle Service Manual Check Vehicle Service Manual 1983 1984 Thick Film Ignition IV TFI IV Check Vehicle Service Manual GENERAL MOTORS Thru 1974 Breaker Point Ignition BPI Most 1974 1984 Delco Remy High Energy Ignition HE Two versions 1 Integral coil system all V 8 s and most V 6 s so
83. gure 8 10 ELECTRONIC IGNITION MODULE SECONDARY INSULATION TEST Hook Up SSI amp DS Systems FIGURE 8 10 CAUTION When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will il
84. h are unsatisfactory Test No 1 Spark Plug Wire To test the No 1 spark plug wire move the INDUCTIVE PICK UP to a spark plug wire that has already been tested satisfactorily Disconnect and test the No 1 spark plug wire when allowable 8 8 TEST RESULTS A Normal Pattern The downspike of the pattern for the disconnected spark plug should be approximately one quarter as long as the upward spike of the pattern as il lustrated in Figure 8 5 If this pattern is displayed the secondary insulation is satisfactory eee Negative Spike ma SECONDARY INSULATION TEST Normal Pattern GM HEI FIGURE 8 5 B Unsatisfactory Pattern If the pattern displayed shows a short or no downspike for the disconnected spark plug as illustrated in Figure 8 6 there is a secondary insulation problem Short or No Negative Spike ied bd SECONDARY INSULATION TEST Unsatisfactory Pattern GM HEI FIGURE 8 6 28 1 If an unsatisfactory pattern exists for all spark plugs cylinders check for a Cracked or carbon tracking of the rotor b Coil Tower Brush Integral Coil HEI lf one or more but not all spark plugs cylinders test unsatisfactorily check for a Cracked or carbon tracking of the distributor cap towers b Defective spark plug wires Refer to step three be low for instructions on testing individual spark plug wires Defective Spark Plug Wire Test If the above test re sults indicate faulty spark
85. he No 1 spark plug Do not allow this wire to arc to ground The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 15 6 D D Ground Spark Plug Wire Ground the disconnected spark plug wire to the engine block with a jumper wire E Engine On Start vehicle engine Operate at 900 1200 RPM F Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 15 5 and 15 6 Read the pattern on the 25 KV scale G Engine Off Turn vehicle engine off H Reconnect Reconnect spark plug wire 15 8 TEST RESULTS A Normal Pattern The spark voltage of the grounded distributor terminal should be approximately 8 KV Spark voltage for grounded cap tower should be approximately 8 KV 20 Required voltage 0 ROTOR GAP TEST Normal Pattern HEI TFI FIGURE 15 5 B Unsatisfactory Pattern If the spark voltage of the grounded distributor terminal is significantly lower or higher than 8 KV then the pattern is unsatisfactory ROTOR GAP TEST Unsatisfactory Pattern HEI TFI FIGURE 15 6 1 If voltage reading remains high check for a Wrong rotor tip too short b Corroded rotor tip c Defective distributor cap 2 If voltage reading remains low check for a Wrong rotor tip too long b Defective distributor cap CHAPTER 16 ALTERNATOR TEST All Ignition Systems 16 1 DESCRIPTION Faults in alternator
86. ilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test J Adjust Position Controls 1 Set the pattern to the center of the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 16 3 TEST PROCEDURE A Load Charging System Turn on the test vehicle head lights and HI fan to load the charging system This will also increase the height of the pattern B Adjust Pattern Turn the PATTERN POSITION CON TROL 5 to obtain an easily viewable pattern Adjust the PATTERN LENGTH CONTROL 6 so that the pattern com pletely fills the screen Turn the VERTICAL POSITION CON TROL 4 to move the pattern to a viewable position C Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 16 2 through 16 9 Although the basic alternator pattern may vary in vertical size and shape depending on the engine speed and alternator output the pattern dis played on the scope screen should appear similar to the normal pattern illustrated in Figure 16 2 D Accessories off Turn headlights and fan off E Engine Off Turn vehicle engine off 16 4 TEST RESULTS AAAAAAAAAAAAAAAAAAN ALTERNATOR TEST Normal Pattern FIGURE 16 2 A Normal Pattern The norm
87. ined above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 7 7 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position CAUTION Selection of spark plug wires to be disconnected is critical on Ford Electronic Ignition Systems Unless properly selected damage to the ignition system electronics may result DO NOT DISCONNECT V 8 engines V 6 engines 1 6 engines 4 Cylinder engines No 1 or No 8 spark plug wire No 1 or No 4 spark plug wire No 3
88. inent facts when you call or visit 1 6 1 D 1 O 5 6 The model number of your Diagnostic Oscilloscope with Inductive Pickup can be found on the nameplate WHEN ORDERING REPAIR PARTS ALWAYS GIVE THE FOLLOWING INFORMATION PART NUMBER PART DESCRIPTION MODEL NUMBER NAME OF ITEM All parts listed may ve orcerec rc ar Sears Service Center and most HOW TO ORDER Sears stores REPAIR PARTS If the parts you need are not stocked locally your order wi de elec tronically transmitted to a Sears Repair Parts Distribution Center or handling SEARS ROEBUCK AND CO U S A CHICAGO ILLINOIS 60684
89. is one of the most important sys tems of a gasoline engine It delivers the spark to fire the right cylinder at precisely the right time while compensat ing for the engine speed and load Proper functioning of this system and each of its many components is critical to the efficient operation of the engine B The oscilloscope is a precision instrument used to di agnose problems in the ignition system while the engine is running By representing the voltage circuits of the ignition system as waveform patterns on a monitor a technician can diagnose the condition of each component in the sys tem This manual graphically depicts normal and unsatis factory patterns for each test facilitating easy diagnosis of the ignition system To utilize the oscilloscope fully the technician should familiarize himself with the various func tion displays of the oscilloscope the basic pattern of each display the basic sections of specific patterns and the terms used in this manual 4 2 FUNCTION DISPLAYS The Diagnostic Oscilloscope Model No 161 21056 provides five functions Each function creates a different display on the oscilloscope screen These functions and displays are selected with the FUNCTION SELECTOR 3 Figure 2 1 where they are labeled 50 KV COIL 25 KV SPARK DISTRIBUTOR PATTERN 25 KV SUPERIMPOSED and ALT alternator The displays are adjusted with the VER TICAL POSITION CONTROL 4 the PATTERN POSITION CONTROL 5 and the PATTERN LENGT
90. ive Coil FIGURE 18 3 18 5 DEFECTIVE CONDENSER A pattern that lacks os cillation at the beginning but has normal oscillation follow ing the point close signal as illustrated in Figure 18 4 in dicates a defective condenser Refer to Chapter 11 Lack of oscillations Existence of oscillations at point close Pattern indicating Defective Condenser FIGURE 18 4 18 6 FAULTY SPARK PLUGS Shorted spark plugs and wide plug gaps can be detected by close examination of the spark line displayed in the pattern refer to Figure 18 5 A short high spark line indicates a wide plug gap A long low spark line indicates a shorted plug Pattern Indicating Faulty Spark Plugs FIGURE 18 5 59 18 7 AUXILIARY GAP SPARK PLUGS Auxiliary gap spark plugs produce a jagged spike at the end of the spark line and cause the tail of the first oscillation to appear al ternately short and long Refer to Figure 18 6 A No 1 engine section e RA Rotary Engine Pattern FIGURE 18 8 Auxiliary Gap Spark Plugs Pattern FIGURE 18 6 18 8 MAGNETO SYSTEM A magneto system pattern alternates polarity with each spark plug firing as illustrated in Figure 18 7 Do not use the 25 KV SPARK Voltage posi tion on the scope when testing a magneto system as it responds to one polarity only Use either the DISTRIBUTOR pattern or 50 KV positions to view these waveforms Magneto System Pattern FIGURE 18 7 18 9 ROTARY ENGINE A Ma
91. ket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive battery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 7 4 2 E CORE COIL SYSTEMS GM HEI FORD TFI TEL and IV FIGURE A 7 44 INTEGRAL COIL GM HEI FIGURE 7 4B MAXIMUM COIL OUTPUT TEST Hook Up GM HEI TFI WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark 710 ignite the gasoline vapors and cause a fire or 217 osion NOTE ACITIVE and INDUCTIVE PICK ely enclose ignition wires and are 2 Dirty or incompletely enclosed striggering and or faulty calibra 0 Ka ro 21 NOTE In some HEI systems the coil is mounted in the distributor and requires the use of the HEI PATTERN CAPACITIVE PICK UP 10 for this test The following paragraphs provide hook up instructions for both ex ternally and internally mounted coils Be sure to use the correct pick up for the system being tested C CAPACITIVE PICK UP 9 or GM HEI PATTERN CA PACITIVE PICK UP 10 Connections 1 CAPACITIVE PICK UP 9 Use the CAPACITIVE PICK UP 9 for HEI and TFI systems with the ignition coil mounted externally Figure 7 4A a Scope Plug the yellow CA
92. lamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test 2 K Adjust Position Controls
93. ld match the normal pattern illustrated in Figure 6 2 The firing lines of the spark plug patterns should extend upward C Engine Off Turn vehicle engine off 6 4 TEST RESULTS A Normal Pattern The firing lines of the spark plug pat terns extend upward SPARK POLARITY TEST Normal Pattern FIGURE 6 2 B Unsatisfactory Pattern The firing lines of the spark plug patterns extend downward SPARK POLARITY TEST Unsatisfactory Pattern FIGURE 6 3 If an unsatisfactory pattern exists check for a Reversed coil connections b Incorrect or defective coil c Reversed battery connections CHAPTER 7 MAXIMUM COIL OUTPUT TEST AVAILABLE VOLTAGE SECTION 1 BPI EIS EIS MMC EIS HALL and BID Systems 7 1 DESCRIPTION For any ignition system to function properly the ignition coil must be able to produce a high secondary voltage Failure of the ignition coil to produce adequate voltage may cause the engine to misfire under load or at high speed The maximum secondary voltage produced by an ignition coil can be measured in this test to ensure adequate voltage CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow
94. ltage requirements of each cylinder in an engine under load to determine if any faults are present CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 9 6 HOOK UP PROCEDURE Refer to Figure 9 4 A or B The scope controls and cables are numbered in Figure 9 4 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figures 9 4A and B WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion EXTERNAL COIL GM HEI AND FORD TFI FIGURE 9 4A SPARK VOLTAGE UNDER LOAD TEST Hook Up GM HE INTEGRAL COIL GM HEI FIGURE 9 4B SPARK VOLTAGE UNDER
95. luminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and Slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 8 15 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position CAUTION Selection of spark plug wires to be disconnected is critical on Ford Electronic Ignition Systems Unle
96. me in line 6 s and 4 s 2 Externally mounted coil system some in line and V 6 s 8 Ae The vast majority of these vehicles are breaker point some High Performance models may use some form of elec tronic ignition See your vehicle service manual for specifications 14 Table 5 2 Oscilloscope Tests kE o o Cc O D a O C Cc O gt 5 S AE O mn 5 x a c o a SS DI o TAE 2 EIS Si 15 8 S ei 3 el sl O A po gt lS Sio 316 ol S A Nae S SE lt 1 Ole cie E J213 5552 22 nin gt o AIO NJOI I gt ce lolz z era em Poca im E a SC tee Ens I lt ENE EEN ENE cic O O OIO 9101010 OIO IGNITION SYSTEM Delco Remy HEI x x ES Chrysler Electronic Ignition EIS EIS MMC Mitsubishi Motor Corporation EIS Domestic 4 cyl Hall Effect Motor Craft Solid State Ignition SSI en eeh a PEER ee E Thick Film Ignition Thick Film Ignition IV TFI IV Prestolite Breakerless xIx X Inductive Discharge BID X indicates applicable Chapter 15 5 3 Waveshape Identification Extensive use of illustra tions has been made throughout this manual Many of these are actual photographs of the waveshapes and pat terns you will be observing Due to the size reduction of many of the illustrations used some waveshape detail has been reduced to the point where it is difficult to s
97. n problems He compares the test patterns displayed on the scope with the patterns illustrated in this manual patterns generated by ar ignition system that is functioning properly Differences and variations in patterns indicate defective com ponents which cause the system to operate improperly By performing the tests and comparing scope pat terns defective components can be located and repaired or replaced B Oscilloscope Patterns The unique test procedures and methods included in this manual place attention on individual portions of a scope pattern in a logical sequence This sequence assures the technician that every portion of the waveform will be analyzed accurately and makes locating problems almost automatic This diagnostic sequence allows complete engine ignition system testing to be performed even without a full understanding of the scope pattern C Oscilloscope Features The Diagnostic Oscilloscope has several features that make scope testing clear and simple The spark voltage pattern yields a sharp uncluttered picture of the spark voltage peaks allowing the technician to analyze problems easily The clamp on INDUCTIVE PICK UP and CAPACITIVE PICK UP provide more stable patterns and eliminate the need to disconnect ignition wires during hook up A large 9 inch screen rotary function selector automatic focusing and brightly illuminated pattern display are among the other highlights of this scope It should be noted that this scope do
98. n systems use a magnetic pickup coil and reluctor assembly in place of contact points Faults in operation of this assembly may be determined by this test This test is indicated when no start hard start or vehicle bucking when driving condition is encountered CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTIGN Do not attempt to test Hall effect ignition systems us ing this test procedure The Hall effect switch could be destroyed 17 10 HOOK UP PROCEDURE Refer to Figure 17 7 The scope controls and cables are numbered in Figure 17 7 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the engine block as shown in Figure 17 7 ATTACH CLIPS AS SHOWN TO ELECTRONIC MODULE ae MAGNETIC PICK UP COIL TEST Hook Up Ford Systems
99. ne if any faults are present CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 9 2 HOOK UP PROCEDURE Refer to Figure 9 1 The scope controls and cables are numbered in Figure 9 1 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 9 1 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion SPARK VOLTAGE UNDER LOAD TEST Hook UP FIGURE 9 1 Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty
100. ntact points Faults in operation of this assembly may be determined by this test This test is indicated when no start hard start or vehicle bucking when driving condition is encountered CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Do not attempt to test Hall effect ignition systems us ing this test procedure The Hall effect switch could be destroyed 17 6 HOOK UP PROCEDURE Refer to Figure 17 4 The scope controls and cables are numbered in Figure 17 4 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the engine block as shown in Figure 17 4 56 IGNITION Msl ICK UP COIL LEADS MAGNETIC PICK UP COIL TEST Hook Up EIS FIGURE 17 4 WARNING When making electrical test connections to the
101. ntrol adjustment procedures described previously in this section Be sure to use the proper capacitive pick up 9 or 10 as required by your particular system integral or external coil See Figure 9 4A or B B TEST PROCEDURE 1 Start and warm up the vehicle engine 2 While observing the scope pattern slowly accelerate from curb idle to about 2500 RPM and de celerate smoothly back to curb idle C RESULTS Dwell should increase smoothly as engine speed in creases and decrease smoothly as engine speed de creases Any sign of jumping or erratic indication dur z this test may indicate a defective electronic zz Check for corroded or loose connections throug 7 ignition system however before replacing the moc CHAPTER 11 COIL CONDENSER TEST BREAKER POINT IGNITION SYSTEM 11 1 DESCRIPTION Energy remaining in the coil after the spark plug has fired must be dissipated properly to pro tect the points This test measures the dissipation of the voltage and determines if there is a fault in the coil or the condenser CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 11 2 HOOK UP PROCEDURE Refer to Figure 11 1 The scope controls and cables are numbered in Figure 11 1 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure prop
102. nts will affect the height of the firing line displayed on the scope 2 Spark Line The spark line represents the voltage which is required to maintain a spark at the spark plug gap to burn the fuel mixture in the cylinder This 12 section of the pattern displays a nearly horizontal line extending to the right of the vertical firing line but should show some random ripple due to the burning air fuel mixture The components which affect this section are the spark plug the plug wire and the coil wire as well as air fuel mixture cylinder condition and compression Abnormal conditions with any of these components will affect the angle and continuity of the spark line B Coil Condenser Section The coil condenser section of the Spark Plug Ignition Pattern represents the dissipa tion of energy remaining in the coil and condenser after the spark plug has finished firing In the waveform this section displays a line of several oscillations which extend to the right from the spark line and diminish in size The compo nents which affect this section are the coil the condenser coil wire or in the case of electronic ignition possibly the module Abnormal conditions with any of these com ponents will affect the appearance of the oscillations in this section of the pattern C Dwell Section The dwell section of the Spark Plug Igni tion Pattern is composed of the point close signal and the point open signal 1 Point Close Signal
103. oil tower wire between the coil tower and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 10 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the 25 KV SUPERIMPOSED position NOTE Many Chrysler and Ford Breaker Point Systems use an offset breaker plate in the distributor Under normal operating conditions dwell variation of about 6 is typical This variation is due to the action of the vacuum advance diaphragm on the distributor For this test disconnect and plug any vacuum lines going to this diaphragm With hoses disconnected the dwell variation should be as indicated below Be sure to reconnect the hoses after the test is finished B Adjust Pattern With the VERTICAL POSITION CON TROL 4 the PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 adjust the superimpos ed ignition pattern to be the same width as the POINT DWELL IN DEGREES scale Align the right edge of the pat tern with the SET LINE on the right side of the screen and the left edge of the pattern with the left edge of the scr
104. on tracking of the distributor cap towers Defective spark plug wires Refer to step three be low for instructions on testing individual spark plug wires b 3 Defective Spark Plug Wire Test lf the above test results indicate faulty spark plug wires perform the following procedure to determine which spark plug wires are defective CAUTION Most Chrysler domestic 4 cylinder engines use a positive locking terminal electrode spark plug wire that can be removed only from the INSIDE of the distributor cap Damage may result to the com ponents if other means of removal are attempted Refer to your service manual a Select the first wire that produced an unsatisfac tory pattern in the test above and disconnect the wire at the distributor cap b Perform the Secondary Insulation Test for this spark plug wire c If the pattern for this spark plug is unsatisfactory when tested with the spark plug end discon nected and is satisfactory with distributor cap end disconnected the spark plug wire is defective d Repeat steps a through c for each spark plug wire that tested unsatisfactorily in the Secondary Insu lation Test with the plug end disconnected SECTION IV FORD SSI DS SYSTEMS 8 13 DESCRIPTION The secondary ignition circuit is the path of voltage from the coil to the gap of each spark plug s electrodes This test checks the secondary ignition circuit for proper insulation A break in the insulation of the se
105. ontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature i Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the first spark plug firing cycle pattern fills the entire screen 12 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the DISTRIBUTOR PATTERN position B Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results figures 12 2 and 12 3 The pattern displayed on the scope screen should match the no
106. operation can be determined by analysis of the scope patterns produced in this test WARNING The gases generated by a charging battery are highly explosive Do not smoke or permit flame or spark to occur near a battery at any time particularly when it is charging Any room or compartment containing charging batteries should be well ventilated to pre vent accumulation of explosive gases To avoid sparks do not disturb the battery charger connec tions while battery is charging and always turn charger off before disconnecting the battery clips When removing or reconnecting battery cables make sure ignition switch and all accessories are turned off It is advisable to blow across the top of the battery before making or breaking connections to it This will disperse any explosive gases which may have accumulated on it CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 16 2 HOOK UP PROCEDURE Refer to Figure 16 1 The scope controls and cables are numbered in Figure 16 1 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following conne
107. or No 5 spark plug wire No 1 or No 3 spark plug wire C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any properly selected spark plug wire with boot at the spark plug end except the wire leading to the No 1 spark plug Do not allow this wire to arc to ground The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 7 6 D D Engine On Start vehicle engine E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 7 5 and 7 6 The pattern displayed on the scope screen should match the normal pattern illustrated in Fig ure 7 5 The pattern illustrated is for the GM HEI system Oscillation detail on the TFI system may be different refer to chapter 5 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire 7 8 TEST RESULTS A Normal Pattern The secondary voltage available for the disconnected spark plug should be greater than 35 KV on GM HEI and 40 KV on Ford TF systems as read on the 50 Kilovolt scale If a satisfactory pattern exists both the primary and secondary circuits are operating normally aes awe 35 to 40 KV seen LH MAXIMUM COIL OUTPUT TEST Normal Pattern GM HEI FIGURE 7 5 B Unsatisfactory Pattern An unsatisfactory pattern shows a maximum available voltage of significantly less than 35 KV on the Kilovolt scale Less than 35
108. or gap will display less pronounced variations in the patterns SPARK VOLTAGE UNDER LOAD TEST Normal Pattern FIGURE 9 2 B Unsatisfactory Pattern A fault exists if the spark volt ages are not uniform or if the voltage increase is either too small or too great Spark voltage high spark voltage low SPARK PLUG VOLTAGE TEST Unsatisfactory Pattern FIGURE 9 3 1 If all voltages are uniform but high check for a Worn or widely gapped spark plugs Open high tension coil wire Large rotor gap Defective distributor cap Retarded ignition timing Overall lean fuel mixture g Auxiliary gap spark plugs 2 If all voltages are uniform but low check for a Closely gapped spark plugs b Advanced ignition timing c Overall low compression d Rich fuel mixture 3 If one or more voltges are high check for a Worn or widely gapped spark plug b Open spark plug cable c Cocked or worn distributor cap 0 Oo FT d Unbalanced fuel mixture 2 or 4 barrel carburetor only 4 If one or more voltages are low check for a Fouled or closely gapped spark plug b Shorted spark plug cable or cracked insulator c Low compression cylinder d Unbalanced fuel mixture 2 or 4 barrel carburetor only SECTION Il GM HEI AND FORD TFI SYSTEMS 9 5 DESCRIPTION The spark voltage of all cylinders should be fairly uniform and rise slightly when the engine is snap accelerated This test measures and compares the vo
109. oration introduced the Elec tronic Ignition System as standard equipment on its entire passenger car line This system replaced the breaker points with a magnetic pickup and transistor switching circuit Each major automobile manufacturer has since designed devel oped or adapted a variety of electronic improvements of the breaker points ignition system The result of these im provements has affected oscilloscope testing in a variety of ways Each system has a distinctively unique oscilloscope waveform pattern and falls into a variety of groupings for hook up procedures test procedures and test results For this reason it is essential that the technician know which ig nition system is used in the test vehicle in order to select the appropriate oscilloscope tests as described in this manual A Identify Ignition System Refer to Table 5 1 to identify the test vehicle s ignition system Refer to the vehicle manufac turer s service manual to verify this identification B Select Tests Refer to Table 5 2 to select the appropriate oscilloscope tests Table 5 1 Ignition System Identification Manufacturer Ignition System Qualification Year AMERICAN MOTORS Thru 1974 1975 1977 1977 1984 Ignition SSI 1980 1983 Ignition HEI Motorcraft SSI CHRYSLER CORPORATION Thru 1972 Prestolite Breakerless Inductive Discharge BID Motorcraft Solid State Delco Remy High Energy Delco Remy HEI Breaker Point I
110. ound on the vehicle such as the alternator bracket as shown in Figure 13 1A B or C 2 CYLINDRICAL COIL SYSTEMS FIGURE 13 1A SECONDARY RESISTANCE TEST Hook Up WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion E CORE COIL SYSTEMS GM HEI FORD TFI TFI l and IV FIGURE 13 1B INTEGRAL COIL GM HEI FIGURE 13 1C SECONDARY RESISTANCE TEST Hook Up NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns 45 C CAPACITIVE PICK UP 9 or GM HEI PATTERN CA PACITIVE PICK UP 10 Connections 1 CAPACITIVE PICK UP 9 Use the CAPACITIVE PICK UP 9 for HEI and TFI systems with the ignition coil mounted externally Refer to Figure 13 1 B a Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope b Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire HEI PATTERN CAPACITIVE PICK UP 10 Use the HEI PATTERN CAPACITIVE PICK UP 10 for HEI systems with the ignition coil mounted internally in side the distributor cap Refer to Figure 13 1C a Scope Plug the yellow HEI PATTER
111. oximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and the No 1 spark plug wire being tested with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 8 7 TEST PROCEDURE A Engine Off Turn vehicle engine off B Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position CAUTION Do not disconnect spark plug wires at the distributor during testing on the HEI systems CAUTION Selection of spark plug wires to b
112. pattern exists at the point open signal check for a Dirty Points b Burned points c Pitted points d Faulty condenser D Oo OD D 44 CHAPTER 13 SECONDARY RESISTANCE TEST ALL IGNITION SYSTEMS 13 1 DESCRIPTION A limited amount of resistance is built into the secondary circuit to extend the spark plug electrode life and to minimize interference with radio and television reception Excessive resistance dissipates the energy needed to maintain good ignition during high speed operation This test checks for excessive secondary resis tance CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 31 2 HOOK UP PROCEDURE Refer to Figure 13 1 A B or C The scope controls and cables are numbered in Figure 13 1 as a reference for hookup This procedure ex plains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connec tions leads and sockets are color coded and keyed to en sure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative gr
113. ps a through c for each spark plug wire that tested unsatisfactorily in the Secondary Insu lation Test with the plug end disconnected SECTION II GM HEI Ford TFI TELL TFI IV Systems 8 5 DESCRIPTION The secondary ignition circuit is the path of voltage from the coil to the gap of the spark plugs electrodes This test checks the secondary ignition circuit for proper insulation A break in the insulation of the sec ondary circuit will cause voltage to arc to ground instead of to the corresponding spark plug and cylinder This re sults in the misfire of the spark plug CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION or cars equipped with a catalytic converter recon ect spark plug wire as quickly as possible to avoid zamage to converter Do not allow car to run with a 2 ug not firing overheating will result 8 6 HOOK UP PROCEDURE Refer to Figure 8 4 A or B e scope controls and cables are numbered in Figure 8 4 lt and B as a reference for hookup This procedure explains ere to hook up each cable on the back of the scope and 7 the vehicle being tested The scope connections leads d sockets are color coded and keyed to ensure proper cokup The scope items are described in detail in Chapter Figure 2 1 Table 2 1 Engine Off Do not star
114. rbon tracking in the rotor d Cracked or carbon tracking in the center tower of the distributor cap lf one or more but not all spark plugs cylinders test unsatisfactorily check for a Cracked or carbon tracking in the distributor cap towers b Defective spark plug wires Refer to step three be low for instructions on testing individual spark plug wires Defective Spark Plug Wire Test If the above test re sults indicate faulty spark plug wires perform the fol lowing procedure to determine which spark plug wires are defective a Select the first wire that produced an unsatisfac tory pattern in the test above and disconnect the wire at the distributor cap Perform the Secondary Insulation Test for this spark plug wire If the pattern for this spark plug is unsatisfactory when tested with the spark plug end discon nected and is satisfactory with distributor cap end disconnected the spark plug wire is defective Repeat steps a through c for each spark plug wire that tested unsatisfactorily in the Secondary Insu lation Test with the plug end disconnected CHAPTER 9 SPARK VOLTAGE UNDER LOAD TEST SECTIONI BPI ALL CHRYSLER FORD SSI 8 DS AND PRESTOLITE BID SYSTEMS 9 1 DESCRIPTION The spark voltage of all cylinders should be fairly uniform and rise slightly when the engine is snap accelerated This test measures and compares the voltage requirements of each cylinder in an engine under load to determi
115. reae ta eae beans yaad Eet ew Ee a ee ESA 7 6 HOOK UP PROCEDURE aducir uan a Be eae dt nc hee Ms 7 7 TEST PROCEDURE ma Gerea aa a a a a a aa EEN 7 8 TESTRESULIS SS ES A RA A A be A ANORMAL Patern tt tapo AE IA AA RA B Unsatisfactory Pana Io EE Section III Ford Solid State and Dura Spark Ignition Systems 7 9 DESCRIPTION ri AA E Ares 7 10 HOOK UP PROCEDURE EE EE 7 11 TESTPROGEDURE ada A daa 7 12 TESTRESULES e at PEST ek AS Gah Cah ideada A Normal Paternidad teed eho Bhs Ita Aik lien endo ad eat B Unsatisfactory PAUSINI A na CHAPTER 8 SECONDARY INSULATION TEST Section Breaker Point Ignition System 8 1 Se lan DEE 8 2 HOOK UP PROCEDURE eet eg ds ii 6 iw eae re 8 3 RSR ele RE Ee 8 4 TEST RESULTS aras asas A Normal Pattern ara a AS E at B Unsatisfact ry Patern as TEO AOS AA ARAS AT Section Il GM HEI and FORD TFI Systems 8 5 DESCRIPTION a Rea 8 6 HOOKUP PROCEDURE cita do tada 8 7 REENEN a ee 8 8 RRE Be INOUE NEEN Br SUNSAUSIECION Pattern issa wrasse tae vice Ghee A fed wee ea ee ea eho aie Section Ill Chrysler Electronic Ignition Systems 8 9 DESCRIPTION parties dd A eee Outen da eta dicos 8 10 HOOK UP PROCEDURE verda a nica AS ox dated baked wits 8 17 RAN PROC EE 8 2 TEST RESULTS rca tado ata ra Aere Nee dios E EE A e ed O E A O ER Section IV Ford Solid State and Dura Spark Ignition Systems 8 13 DESCRIPTION spero et EE da MES 8 14 Ee Ee 8 15 EE BOTAR Pu cr Oy kek a AA as 8 16 ESTAS rt A is
116. rect valve timing Worn lobes on camshaft Defective spark plugs Defective ignition points Faulty ignition coil 62 SPARK KNOCK DETONATION Spark knock detonation causes a metallic ringing sound often described as a ping and is usually encountered when the engine is laboring accel erating rapidly or overheating Carbon deposits in combustion chamber Ignition timed too early Faulty distributor advance governor weak springs Spark plugs Incorrect type of plug using a plug which is too hot Porcelains or electrodes carbonized or burned Lean fuel mixtures Excessive engine temperatures Poor grade of fuel Inoperative manifold heater valve valve held in closed position Inoperative EGR valve ENGINE BACKFIRING THROUGH CARBURETOR Improper ignition timing Improperly seating valves especially intake Incorrect valve timing Worn lobes on camshaft Excessively lean carburetor mixture Intake manifold air leaks Defective cylinder head gasket especially between cylinders Poor quality of fuel Secondary wires improperly installed crossed in distributor cap Distributor centrifugal weights sticking Engine cold and choke too lean No accelerator pump action ENGINE CONTINUES TO RUN AFTER IGNITION IS TURNED OFF DIESELING Idle speed set too high Improper engine timing Too high a heat range on spark plugs Defective idle stop solenoid Inoperative emission controls Exc
117. res are defective a Select the first wire that produced an unsatisfac tory pattern in the test above and disconnect the wire at the distributor cap Perform the Secondary Insulation Test for this spark plug wire If the pattern for this spark plug is unsatisfactory when tested with the spark plug end discon nected and is satisfactory with distributor cap end disconnected the spark plug wire is defective Repeat steps a through c for each spark plug wire that tested unsatisfactorily in the Secondary Insu lation Test with the plug end disconnected SECTION V BID System 8 17 DESCRIPTION The secondary ignition circuit is the path of voltage from the coil to the gap of each spark plug s electrodes This test checks the secondary ignition circuit for proper insulation A break in the insulation of the sec ondary circuit will cause voltage to arc to ground instead of to the corresponding spark plug and cylinder This re sults in the misfire of the spark plug CAUTION Do not let test cables rest or fall on or near hot or moving engine parts CAUTION Use caution when disconnecting and connecting spark plug and high tension wires as they can be damaged easily CAUTION On cars equipped with a catalytic converter recon nect spark plug wire as quickly as possible to avoid damage to converter Do not allow car to run with a plug not firing overheating will result 8 18 HOOK UP PROCEDURE Refer to
118. ributor cap a Scope Plug the yellow HEI PATTERN CAPACI TIVE PICK UP 10 connector into the yellow socket on the back of the scope b Vehicle Clip the HEl PATTERN CAPACITIVE PICK UP 10 onto the top of the distributor cap D INDUCTIVE PICK UP 8 Connections 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto the spark plug wire of the No 1 spark plug Connect the pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 25 KV SPARK position F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Speed Adjust engine speed as required to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up
119. rmal pattern illustrated in Fig ure 12 2 C Using the PATTERN POSITION CONTROL parade the spark plug firing cycles through from left to right one at a time pausing and observing each spark plug s pattern as described in step 12 3 B D Engine Off Turn vehicle engine off 12 4 TEST RESULTS A Normal Pattern Proper point action is most obvious in the dwell section of the ignition scope pattern The point close signal is composed of a downward line followed by several diminishing oscillations The point open signal is represented by an abrupt 90 degree angle upward Downward line followed by several oscillations Abrupt 90 degree angle POINT ACTION TEST Normal Pattern BPI FIGURE 12 2 B Unsatisfactory Pattern When the point close signal lacks oscillations or the point open signal appears unusual the pattern is unsatisfactory and represents faults in the breaker point action Point close signal lacks oscillations Unusual point open signal POINT ACTION TEST Unsatisfactory Pattern BPI FIGURE 12 2 1 If an unsatisfactory pattern exists at the point close signal check for Dirty Points Burned points Point misalignment Point bounce Weak point spring tension NOTE New points may produce a pattern with few or in termittent oscillations at point close This is not ab normal and should correct itself after the points have become properly seated 2 If an unsatisfactory
120. rmal operating temperature NOTE If vehicle is equipped with a non resistor coil wire replace the high tension coil wire with resistance wire just for this test Adjust Position Controls 1 Set the trace to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 With the PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 adjust the trace so that it fills the screen 14 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position B Disconnect High Tension Coil Wire Remove the high tension coil wire from the distributor cap Keep the ex posed end of high tension wire from grounding C Crank Engine With ignition switch on crank vehicle 1 If the voltage reading is under 20 KV check for engine and observe the pattern a Low battery D Check Pattern Compare the pattern displayed on the b Failure of ballast resistor bypass circuit scope with the patterns illustrated below in Test Results c Defective coil Shorted turns carbon tracking Figures 14 2 and 14 3 The pattern displayed on the scope cracked screen should match the normal pattern illustrated in Figure Defecti 14 2 Observe the coil output voltage on the 50 KV scale eee ner Defective coil wire Excessive distributor resistance Inoperative contact points E Reconnect Reconnect the high tension coil wire 14 4 TEST RESULTS A Normal Pattern When the primary
121. s 1 Scope Plug the blue INDUCTIVE PICK UP 8 con nector into the blue socket on the back of the scope 2 Vehicle Clamp the INDUCTIVE PICK UP 8 onto th spark plug wire of the No 1 spark plug Connect th e e 23 pick up as close as possible to the distributor to minimize interference from adjacent wires E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controis 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Idle Speed Adjust engine speed as re quired to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes 3 If vehicle is equipped with non resistor spark plug
122. s test is indicated when no start hard start or vehicle bucking when driving condition is encountered CAUTION Do not let test cables rest or fall on or near hot or moving engine parts 17 2 HOOK UP PROCEDURE Refer to Figure 17 1 The scope controls and cables are numbered in Figure 17 1 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the engine block as shown in Figure 17 1 MAGNETIC PICK UP COIL TEST Hook Up HEI FIGURE 17 1 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion CAUTION Do not allow PICK UP COIL TEST LEAD clips to touch each other or the vehicl
123. s warmed up for approximately 30 seconds a horizontal trace will appear on the screen b NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start Engine Start the engine and allow it to warm to normal operating temperature Adjust Engine Speed Adjust engine speed as required to provide a stable pattern typically 900 1200 RPM J Adjust Scope Pattern If the scope pattern blinks or is unstable 1 Ensure that pick up clamps are clean and com pletely enclose ignition wires 2 Turn the INDUCTIVE PICK UP 8 clamp over and slide it along the spark plug wire between the spark plug and the distributor until pattern stabilizes If vehicle is equipped with non resistor spark plug wires replace the ignition coil wire and No 1 spark plug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 6 3 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the 50 KV COIL position B Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results 18 Figures 6 2 and 6 3 The pattern displayed on the scope screen shou
124. scope controls and cables are numbered in Figure 10 1 as a reference for hookup This procedure explains where to hook up each cable on the back of the scope and on the vehicle being tested The scope connections leads and sockets are color coded and keyed to ensure proper hookup The scope items are described in detail in Chapter 2 Figure 2 1 Table 2 1 A Engine Off Do not start the engine before hookup B POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive bat tery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 10 1 2 WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion DWELL AND VARIATION IN DWELL TEST Hook Up BPI FIGURE 10 1 39 NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 conne
125. ss properly selected damage to the ignition system electronics may result DO NOT DISCONNECT V 8 engines V 6 engines I 6 engines 4 Cylinder engines No 1 or No 8 spark plug wire No 1 or No 4 spark plug wire No 3 or No 5 spark plug wire No 1 or No 3 spark plug wire C Spark Plug Wire Disconnect With the fiber pliers pro vided disconnect any properly selected spark plug wire with boot at the spark plug end except the wire leading to the No 1 spark plug Do not allow this wire to arc to ground The INDUCTIVE PICK UP should be clamped to the No 1 spark plug wire as instructed above in paragraph 8 14 D D Engine On Start vehicle engine E Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results figures 8 11 and 8 12 The pattern displayed on the scope screen should match the normal pattern illustrated in figure 8 11 32 F Engine Off Turn vehicle engine off G Reconnect Reconnect spark plug wire H Test Remaining Spark Plug Wires Repeat the test procedure with each spark plug wire except the wire lead ing to the first spark plug in the firing order see next step Make a note of which cylinder patterns are normal and which are unsatisfactory Test No 1 Spark Plug Wire To test the No 1 spark plug wire where permissible according to the chart above move the INDUCTIVE PICKUP to a spark plug wire that has already b
126. t Frayed or broken wire lead from coil to distributor Corroded dirty or loose connections Defective condenser Defective distributor points Open ballast resistor Defective coil Secondary Circuit Corroded ignition cable terminals Coil tower cable not properly seated in distributor Open coil tower cable Cracked insulation on ignition cables Weak or defective coil 61 components Cracked distributor cap Damaged or defective spark plugs Damaged or defective rotor Ignition Switch Loose contacts Corroded or defective contacts Ballast bypass circuit defective Starter Motor Defective starter solenoid Open or shorted windings Starter pinion damaged or stuck in fly wheel gear Slipping clutch in drive pinion Faulty neutral safety switch on cars with automatic transmission 3 Poor Engine Compression resulting from Loose cylinder head bolts Loose spark plugs Damaged or leaking cylinder head gasket Damaged or burned valve seats Weak or broken valve springs Improper valve clearance or warped or gummed valve stems Worn broken weak or stuck piston rings Scored cylinder walls Cracked cylinder block Excessive internal engine friction SPARK PLUG PROBLEMS Cracked exterior porcelain Improperly spaced gap Fouled plugs Incorrect ignition coil polarity ENGINE MISFIRES WHEN IDLING NORMAL ENGINE TEMPERATURE Air leaks in intake manifold or carburetor resulting from Loose manifold
127. t the engine before hookup POWER LEAD Connections Make the following connections 1 Scope Plug the black POWER LEAD 7 connector into the black socket on the back of the scope 2 Vehicle Connect the POWER LEADS 7 to the bat tery as follows the RED clip to the Positive battery terminal and the BLACK clip to Negative ground on the vehicle such as the alternator bracket as shown in Figure 8 4 Di 1 pu U Ie Tee E CORE COIL SYSTEMS GM HEI FORD TFI TFI l and IV FIGURE 8 4A SECONDARY INSULATION TEST Hook Up GM HEI Ford TFI WARNING When making electrical test connections to the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion INTEGRAL COIL HE FIGURE 8 4B NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns NOTE In some HEI systems the coil is mounted inside the distributor and requires the use of the HEI PAT TERN CAPACITIVE PICK UP 10 for this test The following paragraphs provide hook up instructions for both externally and internally mounted coils Be sure to use the correct pick up for the system being tested C CAPACITIVE PICK UP 9 or GM HEI PATTERN C
128. tNormal paterni ee aun Oaa hada dle duty PE Bs Wnsatisfactory Fater anos A AA tee Bee ar atada Section Ill Ford SSI DSI DSII Ignition Systems 7 9 DES ORI ON ai tres Wace Babak Boda wae ate annie odin CEYDA we hale ESA eee lakes ok hea ene ROOK UP PROCEDURE adria rosadas aes NS A A EE Whee TES RESULTS a o Grae Sa A Norma ert B Unsa sfactory Pattern CHAPTER 18 ADDITIONAL SCOPE PATTERNS 18 1 GENERA_ UE iE rh fra O north hes DEFECTIVE COIL id inven ene irate TA ES het Mies Aa APPENDIX A TUNE UP HIR erg geg Een EE APPENDIX EE EE Eege Ee A C 56 56 57 57 57 57 57 57 58 58 58 59 59 59 59 59 59 60 60 m 61 63 RULES FOR SAFE AUTOMOTIVE TESTING 1 Before starting the engine set the parking brake and place the gear selector in NEUTRAL on standard trans missions and PARK on automatic transmissions The carbon monoxide in exhaust gas is highly toxic To avoid asphyxiation always operate vehicle in a well ventilated area If vehicle is in an enclosed area exhaust should be routed directly to the outside via leak proof ex haust hose To avoid explosion due to spark when operating any test instrument from an auxiliary battery connect a jumper wire between the negative terminal of the auxiliary bat tery and chassis ground on the vehicle under test for negative ground systems For positive ground systems connect the jumper wire to the positive terminal of the au
129. tern for comparison and measurement to determine and locate an abnormal alternator output condi tion Open and shorted diodes and windings rotors and stators can be found easily by waveform comparisons FIRING LINE SPARK LINE POINT OPEN FOR NEXT CYLINDER POINT CLOSE kanana Zeg DWELL ANGLE SPARK COIL CON DENSER SECTION SPARK PLUG IGNITION PATTERN FIGURE 4 6 4 3 SPARK PLUG IGNITION PATTERN Breaker Point Ig nition The Spark Plug Ignition Pattern represents the voltage of the spark plug and distributor through a single spark plug firing sequence The various phases of this voltage sequence can be identified easily as three distinct sections of the waveform pattern These sections are the fir ing section the coil condenser section and the dwell sec tion Figure 4 6 illustrates the normal scope pattern for the firing of one cylinder in a typical Breaker Point Ignition System A Firing Section The firing section of the Spark Plug lg nition Pattern is composed of the firing line and the spark line 1 Firing Line The firing line represents the initial volt age required to arc the rotor and spark plug gaps This section displays a sharp vertical line extending upward The components which affect this section are the spark plug the plug wire the rotor the rotor gap the distributor cap the coil wire the fuel mixture and the cylinder compression Abnormal conditions with any of these compone
130. the ve hicle do not use the carburetor or other fuel system components as a ground connection as a spark could ignite the gasoline vapors and cause a fire or explosion NOTE Ensure that the CAPACITIVE and INDUCTIVE PICK UP clamps completely enclose ignition wires and are free of dirt and grease Dirty or incompletely closed clamps may cause mistriggering and or faulty calibra tion of scope patterns C CAPACITIVE PICK UP 9 Connections 1 Scope Plug the yellow CAPACITIVE PICK UP 9 connector into the yellow socket on the back of the scope 2 Vehicle Clamp the CAPACITIVE PICK UP 9 onto the high tension coil wire D INDUCTIVE PICK UP 8 Connections 1 Scope Do not connect for COIL OUTPUT AT CRANKING SPEED TEST 2 Vehicle Do not connect for COIL OUTPUT AT CRANKING SPEED TEST E Select Function Rotate FUNCTION SELECTOR 3 to 50 KV COIL F Pattern Controls 1 Turn PATTERN POSITION CONTROL 5 clockwise to stop 2 Turn PATTERN LENGTH CONTROL 6 counter clockwise to stop G Turn Scope On Press the POWER ON SWITCH 1 to turn scope ON The switch will illuminate After the Scope has warmed up for approximately 30 seconds a horizontal trace will appear on the screen NOTE A momentary disconnection to the battery will turn scope OFF Reconnect scope cables to the battery as explained above and press POWER ON SWITCH H Start engine Start the engine and allow it to warm to no
131. tres a be AA 3 12 MAGNETIC PICK UP COIL TEST aia Ai RRA CHAPTER 4 BASIC SCOPE PATTERNS 4 1 INTRODUCTION ostor EE 4 2 FUNCTION DISPLAYS Wes Hana aan das Da EN Sl AA O wed eee ann Med teeta lee ead E Be 2S RWSRARIS atan ata da he ne Aert nara Sem RN C DISTRIBUTOR PAT TERN eege EE A ses D 25 KV SUPERIMPOSED EE Es ALTERNATOR estos SS A ARES 4 3 SPARK PLUG IGNITION PATTERN tte sg EN REN lada ENEE Ao FM SECCION e cds a as eebe Se tee tod Ae gr Br Coil Condenser Section OE AE EE EEN C Dwell SOCOM aaa ri Ur daa CHAPTER 5 TYPES OF IGNITION SYSTEMS 5 1 INTRODUCTION cuido aaa ir a OS Fe 5 2 APPLICABLE TESTS FOR EACH IGNITION SYSTEM sica es ds 5 3 WAVESHAPEIDEN TIFICATION ae AA E IA AA ASAS akd 5 4 IGNITION SYSTEM ABBREVIATIONS oct wets go a ec CHAPTER 6 SPARK POLARITY TEST ALL SYSTEMS 6 1 DESCRIPTION rs a A howtos yeas 6 2 HOOK UP PROCEDURE EE 6 3 TEST PROCEDURE det di 6 4 TEST RESULTS ege breet A Ae a Belt uerge eege eech ados A N rmal Pattern EE 5 Unsatistactory Patern aia odo rc sd rd se IRS 00 00 00 ON NNN CHAPTER 7 MAXIMUM COIL OUTPUT AVAILABLE VOLTAGE TEST Section 1 BPI EIS EIS MMC EIS HALL AND BID Systems 7 1 DESCRIPTION dr a e e e 7 2 HOOK UP PROCEDURE aa A Ii eens 7 3 TEST PROCEDURE 220 fect ie awa E AAA AAA ad 7 4 BR Me ET EE Acs Normal Pattern da AS A Ee e A AA B U satist ctory Pattern anidar ri Al es Section Il GM HEI FORD Thick Film Ignition Systems 7 5 DESCRIPTION reses eene
132. ug wire with resistance wire just for this test K Adjust Position Controls 1 Set the pattern to zero line on the scope screen with the VERTICAL POSITION CONTROL 4 2 Adjust PATTERN POSITION CONTROL 5 and PATTERN LENGTH CONTROL 6 so that the pattern fills the entire screen 9 7 TEST PROCEDURE A Select Function Ensure that FUNCTION SELECTOR 3 is set to the 25 KV SPARK VOLTAGE POSITION B Accelerate Engine Snap accelerate the engine by quickly depressing the accelerator pedal and then releas ing it Allow the engine to return to idle between accelera tions Do not hold the accelerator pedal down A snap ac celeration is a very rapid push release of the accelerator pedal C Check Pattern During snap acceleration compare the voltage pattern displayed on the scope with the patterns il lustrated below in Test Results Figures 9 5 and 9 6 D Engine Off Turn vehicle engine off 9 8 TEST RESULTS A Normal Pattern All spark voltages should be fairly uni form and increase slightly 1 2 KV during snap acceleration Engines designed to operate with a large rotor gap will display less pronounced variations in the patterns 37 1 If all voltages are uniform but high check for a Worn or widely gapped spark plugs b Open high tension coil wire externally mounted coil only c Large rotor gap d Defective distributor cap e Retarded ignition timing f Overall lean fuel mixture g Auxili
133. und it by connecting a jumper wire from the metal prod to the engine block E Engine On Start vehicle engine Operate at 900 1200 RPM F Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 15 2 and 15 3 Read the pattern on the 25 KV scale G Engine Off Turn vehicle engine off H Reconnect Reconnect spark plug wire 15 4 TEST RESULTS A Normal Pattern The spark voltage of the grounded distributor terminal should be approximately 3 5 KV BPI only Many of the newer electronic ignitions operate with a significantly higher rotor gap approximately 8 KV Spark voltage for grounded cap tower should be approximately 3 5 KV 20 p Required voltage 0 ROTOR GAP TEST Normal Pattern BPI FIGURE 15 2 50 B Unsatisfactory Pattern If the spark voltage of the grounded distributor terminal is less than 3 KV BPI then the pattern is unsatisfactory LOW ROTOR GAP TEST Unsatisfactory Pattern BPI FIGURE 15 3 1 If voltage reading remains high check for a Wrong rotor tip too short b Corroded rotor tip c Defective distributor cap If voltage reading is excessively low check for a Wrong rotor tip too long b Defective distributor cap SECTION II GM HEI FORD TFI SYSTEMS 15 5 DESCRIPTION Adequate voltage is required to properly arc the gap between the rotor and the distributor cap terminals This test measures the volta
134. ve a helper crank the engine C Check Pattern Compare the pattern displayed on the scope with the patterns illustrated below in Test Results Figures 17 8 and 17 9 The pattern displayed on the scope screen should match the normal pattern illustrated in Figure 17 8 While the engine is cranking gently wiggle or flex the pick up coil wires their full length while observing the scope display The pattern shown in Figure 17 8 should remain constant If there is any sign of erratic operation check the pick up coil wires for insulation nicks cuts or wear and check the terminals for good connections D Reconnect Remove test leads reconnect all wires and connectors 17 12 TEST RESULTS A Normal Pattern AMPLITUDE MAGNETIC PICK UP COIL TEST Normal Pattern Ford Systems FIGURE 17 8 D Unsatisfactory Pattern A line with no vertical amplitude is an unsatisfactory pattern If an unsatisfactory pattern exists the magnetic pick up coil is not functioning properly Check the pick up coil with an ohmmeter using the following table as a guide Table 17 1 Magnetic Pick Up Coil Resistance Values Purple to Orange Purple or Orange to Ground SSI 1974 1976 400 800 greater than 70 000 DS 1 DSII 400 1000 greater than 70 000 DS ll ESCORT LYNX 650 greater than 70 000 1300 58 NO AMPLITUDE __ lt MAGNETIC PICK UP COIL TEST Unsatisfactory Pattern Ford Systems FIGURE 17 9 CHAPTER
135. xiliary battery and chassis ground on the vehicle When working in a garage or other enclosed area aux iliary battery should be located at least 18 inches above the floor to minimize the possibility of sparks igniting gas oline vapors and causing an explosion An automobile battery is capable of producing very high currents Therefore exercise reasonable care when working near the battery to avoid electrical connections through tools wristwatch etc Avoid contact with battery electrolyte Electrolyte can burn holes in clothing burn skin and cause permanent damage to eyes Always wear splash proof safety gog gles when working around the battery If battery electro lyte is splashed in the eyes or on skin immediately flush the affected area for 15 minutes with large quantities of clean water In case of eye contact seek medical aid im mediately The gases generated by a charging battery are highly explosive Do not smoke or permit flame or spark to oc cur near a battery at any time particularly when it is charging Any room or compartment containing charging batteries should be well ventilated to prevent accumu lation of explosive gases To avoid sparks do not disturb the battery charger connections while battery is charg ing and always turn charger off before disconnecting the battery clips When removing or reconnecting battery cables make sure ignition switch and all accessories are turned off A technique used by many
136. zda two section rotary engine produces two spark patterns one for each engine section These patterns represent the action of either the leading or the trailing ignition depending on which ignition system leading or trailing is being tested The normal pat tern for one engine section is the same as the normal pattern for one cylinder of a piston engine APPENDIX A TUNE UP TIPS ENGINE STARTS HARD or WILL NOT START 1 Carburetor Trouble Due to Excessive moisture on ignition system Faulty choke operation Engine flooded with gasoline Restriction in carburetor passages Defective fuel pump Insufficient supply of gasoline to carbu retor due to Clogged fuel filter Clogged or restricted gas line Leaking carburetor gaskets Damaged or restricted carburetor float Air leaks at carburetor or intake manifold due to Loose manifold or carburetor nuts or Screws Leaking carburetor or manifold gaskets Vacuum line leaks at intake manifold connections or cracked vacuum hoses Leaks in vacuum operated accessories Warped mounting surfaces on carbu retor or manifold Cracked intake manifold Frozen fuel line in cold weather Fuel tank filler cap vent clogged or restricted 2 Electrical Difficulties Battery Low charge or discharged Loose or corroded terminals Poor ground connection Frayed or corroded cables Battery of insufficient capacity Defective alternator or regulator Ignition Primary Circui

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