Fuel Injector Cleaning
Contents
1. TECH In time fuel injector s may become restricted due to buildup in the injector passages Restrictions cause an Injector to run lean Driveability symptoms include difficult starts rough operation and possi ble misfire The MIL may illuminate Injector clean ing has three phases dealing with fretting corrosion Injec tor balance test ing and clean ing Here are some of the reasons behind the procedures Typical Multec II Injector Fretting Corrosion Fretting is a microscopic rubbing motion between the terminal pin on the injector and the terminal in the wiring harness usually caused by injector vibration engine vibration and electrical harness movement It is invisible to the naked eye Oxidized debris corrosion the result of fretting can build up in the injector ter minals resulting in high resistance or loss of continuity A fretted connection is unstable and may vary between good high resistance and open depending on the amount of oxide build up The reason to be concerned about fret Injector Cleaning ting Is that it can cause symptoms that mimic a restricted injector The worst case is a total loss of continuity in the connection that results in injector circuit fault or misfire codes being set If the oxides create a high resistance circuit insufficient current will be available to properly open the injector resulting in unstable fuel delivery Step 1 Stable connecti2. spark plugs Ultimately it s time to change spark plugs when fuel is being left unburned in the combustion chamber As spark plugs fire over time they lose their sharp edges as material from the center and ground electrodes slowly erode away With iridium this process takes quite a long time However as the gap between these two points grows the voltage required to bridge the gap increases This strains the ability of the ignition system to supply enough voltage to completely and efficiently burn the fuel Replacing worn out spark plugs effec tively restores this ability Misfires are reduced power is enhanced and engine operation is more efficient ACDelco Sports Report NASCAR Stock IHRA Drag NHRA CITGO Car Racing Racing POWERade BASSMASTER Busch Series Pro Modified Drag Racing Tournament Driver e Series Pro Stock Trail i Ron Hornaday ka ae Driver Series Angler det Car 2 Chevy fixe Harold Martin Driver Jimmy Houston Monte Carlo Richard Childress Racing Ron Hornaday driving the 2 ACDelco car in the NASCAR Busch Series has 13 top 10 fin ishes and one win this season 2004 Driver Standings Points through 27 of 34 races 1 Martin Truex Jr 4139 6 Ron Hornaday 3382 Car Pontiac Grand Am Harold Martin continues his success this season in the 2004 IHRA Drag Racing PM Series 2004 Driver Standings Points through 11 of 12 races 1 Mike Janis 749 2 Harold Martin 584 Kurt
3. Corporation in the mid 1980s for Mercedes Benz it is now mandated to be on all vehicles by model year 2008 with a gradual phase in already in progress What makes CAN different Mostly speed and simplicity which are normally at odds with each other CAN operates between 83 3Kbps and 500Kbps compared to GM The speed of CAN enables shar ing of real time data Vehicle sys tems with these requirements are primarily powertrain and chassis con trollers such as engine transmis sion and brakes Because there is a common com munication proto col it s easier to transter data For example in the Class 2 system all of the ECUs need ed to be continually awake In CAN some ECUs may be communicating while others are sleeping or in a low power state until asked to perform In effect communication between any collection or sub system of ECUs can be started or stopped independently of any other collection Communicating with CAN Similar to the original OBD protocols mandated by the EPA CAN requires spe cial hardware to communicate with the scan tool The hardware interface for the Vetronix MTS3100 Mastertech is avail able today and includes update software for the Multi Function Tester MFT card to allow it to talk to all emissions based CAN controllers All of the OBDII diagnostic test modes as defined by the Society of Automotive Engineers SAE are sup ported by the MTS3100 Mas
4. cycling the fuel pump this can be accomplished by turning the ignition switch on then off for 30 seconds then back on Fuel system pressure must be at the desired specification in the service manu al Fuel pressure must not leak down at a rate of more than 5 kPa in 30 seconds If a concern exists follow diagnostics in the service manual Next connect the scan tool and select Injector Balance Test Select injector 1 The fuel system will prime Record the Initial Pressure reading immediately after the fuel pump shuts off It is normal for the fuel system pressure to rise due to warm fuels vaporizing Pulse the first injector and record the Pressure After Pulse reading immediately after the injector stops pulsing Select and test each remaining injector record ing both the Initial Pressure and Pressure After Pulse readings Once the testing is completed sub tract the Pressure After Pulse reading from the Initial Pressure reading for each cylinder to determine the pressure drop After determining the amount of pres sure drop for each injector compare the results If the difference between the highest richest and lowest leanest injector is less than 20 kPa the injectors are all flowing within an acceptable range If the difference is 20 kPa or more proceed with cleaning An injector that is considerably richer than the rest must be replaced An injec tor that is leaner than the rest may be restricted and ma
5. limit with a maximum of 80 ppm except for small refiner delays California Phase 3 gasoline will have a maximum sulfur content of 15 ppm In the absence of an identified vehicle condition customers can be advised to temporarily change to a premium grade brand of fuel from a major supplier such as Shell Exxon Texaco or Chevron Premium fuels in general have been found to have lower sulfur levels However even these suppliers can be susceptible in areas where base fuels are delivered either by pipeline or from the same refinery service centers should refrain from 7 attempting repairs or replacing catalytic converters for odor complaints unless there is a MIL indicating a part deficiency Damaged Electrical Terminal 2001 04 Buick Century and Regal A combination of the following intermit tent conditions may be present e noperative instrument panel cluster e Inoperative SES TCS and or ABS lights e Inoperative air bag light e Inoperative power windows Inoperative sunroot Inoperative radio Inoperative turn signals e No crank security light on BTSI stuck in Park 2003 04 only DTCs U1000 U1016 B1422 B2957 B2958 and possibly others These may be caused by a damaged ter minal in the Underhood Accessory Wiring Junction Block also sometimes called the Underhood Bussed Electrical Center or UBEC This terminal provides voltage trom the IGN 1 30 amp fuse to nine circuits in the vehicle s interior If the co
6. 02 Electronic Fuel Systems New Top Tier Detergent Gasoline Top Tier Detergent Gasoline a new class of unleaded gasoline with enhanced detergency that minimizes deposits on fuel injectors intake valves and combustion chambers will be appearing at retail stations of some fuel marketers This gasoline meets new voluntary deposit control standards developed by BMW General Motors Honda and Toyota The U S EPA requires all gasoline sold in the U S to contain a detergent additive However the requirement is minimal and in many cases is not suffi cient to keep engines clean A higher level of detergent is needed than what is required by the EPA Top Tier Deter gent Gasoline exceeds the detergent requirements imposed by the EPA The four corporations recognized the benefits to both the vehicle and the consumer Also joining together empha sized that low detergency is an issue of concern to several automotive companies All vehicles will benefit from using Top Tier Detergent Gasoline which will help keep engines cleaner than gasoline containing the lowest additive concen tration set by the EPA Clean engines help provide optimal fuel economy and performance and reduced emissions Those vehicles that have experienced deposit related problems would espe cially benefit from use of Top Tier Detergent Gasoline The Top Tier program begun on May 3 2004 is a voluntary program initiated by the four automotive compani
7. 38 172 kPa and close between 40 46 psi 275 317 kPa Remember to install the seal onto the A C low pressure switch connector when the diagnosis is complete Refer to GM Bulletin 04 01 38 010 for additional details Rotten Egg Exhaust Odor Three conditions are necessary for rot ten egg or hydrogen sulfide odor to be present in exhaust gasses e Hot catalytic converter e Sulfur in the fuel e Rich air fuel ratio at least momentarily Of these three the quantity of sulfur present in the fuel is the most variable and most difficult for a customer to control High amounts of sulfur in fuel can cause not only a rotten egg odor in exhaust gasses but also certain re active sulfurs can corrode silver contacts in the fuel level sender causing erroneous fuel gauge readings At present there is no EPA requirement for the level of sulfur in fuel outside of the state of California and the ASTM American Society for Testing and Materials specification limit is 1000 parts per million PPM To put that number into perspective the current limit for sulfur in California phase 2 gasolines requires an average of less than 30 PPM In 2004 the EPA began limiting the sul fur content in gasoline The EPA limit for the corporate average sulfur content is 120 ppm and no single gasoline can exceed 300 ppm except for small refiner exemptions By 2006 the corporate aver age will be limited to 30 ppm the current California
8. 534 Buying a Business Grade Computer Promote the goods and services your service center has to offer Get a Deal on a Dell By participa ting In the ACDelco Total Service Support TSS program independent service centers realize a number of benefits that grow their busi ness and help it succeed But being a TSS ser vice center also has many bene fits for the service center s employees Fos Cook Fie Mighall Cime One of those benefits is a discount on Dell computer equipment TSS service center employees are eligible to buy Dell personal computer equipment through Dell s Employee Purchase Program The Dell systems available for pur chase are not intended for use with WISE Through the program you ll receive e 5 10 off Dell s list prices on Dimension desktop PCs and Inspiron notebook computers as well as electronics and accessories printers digital cameras and more The discount is 5 on computer sys tems with a 1 2 year warranty and 10 on comput er systems with a 3 4 year warranty Plus special employee discounts listed on the employee pur chase program web site may be applicable e Access to the 24 7 Dell Technical Service amp Support Line for the life of your computer e Available Dell purchase plans through Dell Financial Services for qualified buyers For additional information or to order online from Dell s Employee Purchase Program web site visit www dell com eppbuy
9. Johnson Car Chevy Cavalier Kurt Johnson and reigning Pro Stock champion Greg Anderson continue their duel for points 2004 Driver Standings Points through 20 of 23 races 1 Greg Anderson 2069 4 Kurt Johnson 1152 Professional Angler Jimmy Houston holds more than 130 top 50 finishes in his career including two top 50 finishes this year 2004 Angler of the Year Standings Points 1 Gerald Swindle 1326 105 Jimmy Houston 623 The following technical tips provide repair information about specific conditions on a variety of vehicles If you have a tough or unusual service repair the TSS Technical Assistance Hot Line can help Call 1 800 825 5886 prompt 2 to speak with a technical expert with the latest OEM information A C Low Pressure Switch Diagnosis 1999 2005 Chevrolet Silverado and GMC Sierra Trucks and 2003 05 Hummer H2 The A C low pressure switch open close pressure switch point cannot be accurately determined by measuring pressure at the low side service port Because the evaporator is between the low side service port and the A C low pressure switch pressures measured at the port may not be the same as those at the switch This difference can cause mis diagnosis of switch operation A new A C diagnostic tool GE 47742 is available from SPX Kent Moore Here are the highlights GE 47742 allows the actual pressures at which the switch opens and closes in the vehicle s refrigerant system to be moni tore
10. The TSS participant D is GS142116812 If you would like assistance in configuring or ordering a Dell computer system call a Dell representative at 1 800 695 8133 e Not assembled with same internal com ponents through product build lifecycle Having the correct PC has become as impor e Built using same components for e Designed for home networking tant to the service center s efficiency and pro generally three to six months configurations ductivity as having the right tools in the toolbox e Ease of serviceability of internal l l When upgrading and adding computer components Preloaded with Internet ready configu equipment to your service center business e Preloaded with business software rations designed for the home user grade or commercial PCs are recommend e Network manageability utilizing For TSS service centers that utilize ed Unlike a consumer grade PC a business grade PC is specifically configured for use in i and maintenance a business network environment PCs in this industry standards to manage setup ACDelco s WISE System there are specific computer hardware requirements which are needed in order to fully take advantage of all class have components designed and sup ported for use in a network environment Additionally they have greater life cycle stability due to designed in serviceability Characteristics of Business Grade PCs e Extended product availability cycles Characteristics of Consumer Gr
11. ade PCs e Designed with multi media hardware features used for gaming video and music e Preloaded with multi media software designed for entertainment 4 of the features of the system Because of continuous advancements in personal com puter hardware as well as enhancements to the WISE System please contact your Regional eBusiness Coordinator to discuss your computer needs The Mastertech CAN A decade has now passed since the first OBDII compliant vehicles rolled off the assembly line When looking back at that period of auto motive history and reflecting on what impact the changes In technology had in the repair process a few things come to mind immediately First service cen ters had to either upgrade their scan tools or replace them to communicate with the four new EPA leg islated OBD protocols Second additional training was required to learn not only how the systems worked but how they were diagnosed and repaired when they rolled into the shop Third OBDII overall was very good for the repair industry It pro vided better diagnostic information on more vehicles than ever before and the do it yourself crowd has diminished cre ating a larger customer base for profes sional service centers Controller Area Network What now The EPA has added a new OBDII protocol to the lineup that started in model year 2003 called CAN or Controller Area Network Developed orig inally by the Robert Bosch
12. cause scan tool operation is nearly identical to previous systems except for better more complete diagnostics DTCs data lists and monitor tests For more information on CAN for the MTS3100 Mastertech and a com plete list of all CAN compliant vehicles contact Vetronix customer support at 1 800 321 4889 ext 4 or visit Vetronix on the web at www vetronix com THE PORTA KEA i MEDEAULO Class 2 at 10 4Kbps and HYHTEN THT MEM does so relatively seamless ly This design allows the intra vehicle network of electronic control units ECU to communicate and share information lightning fast while increasing the net work s ability to self diag nose That s having your cake and eating It too HITIMLIGING THE JEO Ll PTXTERFALE gt Cnt EBE EVAR DZS IGATLOR HRTRD dat gt RECORD wil Ta Le deya lh Supp FUEL talust Adu Uinta me Hestod Cat Simp l i Hiatal nt Idy HEVDE Gus Supp l JKH Fug ina PLEASE WAIT ee CETINE T GRICE a LT a oe Pal COAT IAG 160 IS 765 1 SHA Kbpw 11 bil FRESS EHTER The MTS3100 Mastertech can be used to view the ECU data parameters transferred over a CAN What is Iridium And Other Questions about Spark Plugs ACDelco introduced iridium spark plugs in 2002 Today they are installed as Original Equipment on a vari ety of new vehicle models and are available in many aftermarket applications The spark plug market has changed drastically over t
13. charger e Digital Exhaust Gas Recirculation EGR e Fast heating glow plugs e Closed crankcase ventilating system e Revised fuel system Changes to the turbocharger for exam ple contribute to the power gain of the LLY version of the Duramax 6600 diesel engine An efficient turbocharger spins up fast to produce boost pressure early but does not create excessive exhaust backpressure at the engine s upper operating range The variable nozzle turbocharger fea tures a group of nine adjustable vanes in place of the wastegate used in the LB7 engine The vanes are opened to mini mize flow at the turbine and exhaust backpressure at low engine speeds To increase turbine speed the vanes are closed increasing the velocity of the exhaust gases The variable nozzle turbocharger allows for a quicker acting turbocharger at low power levers while significantly reducing turbine induced exhaust backpressure at high power and rpm levels To learn more about the features of the Duramax 6600 diesel engine contact your WD to find out when the Duramax 6600 Diesel Engine seminar will be held in your area For a more in depth study of the Duramax 6600 diesel engine enroll in the two day Duramax 6600 training course FCD 11 You can review the current ACDelco training schedule and enroll in courses online by clicking on the Training link at acdelcotechconnect com 2 Sete ACDelco CHa L muy FOIN a DENEK ACDelco TechCon
14. d The tool is a three way I fitting With the switch removed from the accu mulator the switch installs into the GE 47742 tool The tool installs in place of the switch in the accumulator Finally the low side gauge of the A C refrigerant recovery and recycling unit such as the ACR2000 connects to the service port on the tool GE 47742 installation A GE 47742 B Connection to accumulator C Low pressure switch D A C unit low side gauge hose Before plugging in the switch wire har ness temporarily remove the seal from the connector The plunger effect of plug ging the sealed connector into the switch induces a 5 10 psi 35 69 kPa pressure on the back side of the switch This pressure will skew the opening closing characteris tics of the switch as much as 5 10 psi 35 69 kPa until the pressure bleeds off which can take 20 minutes or longer Operate the A C system under the following conditions e Engine On e 1500 RPM e A C On e Blower Low e Aux Blower Low e Temperature Full Cold e Aux Temp Full Cold e Inside air Re circ e No sun load in the shade Use a scan tool to determine the low pressure switch status and the A C refrig erant recovery and recycling unit to deter mine low side pressure The scan tool should display the switch status such as with a message of Normal for Closed and Low Pressure for Open A properly operating switch should open between 20 25 psi 1
15. es e Check all vehicle lights including headlights turn signals and brake lights for proper operation Belts and Hoses ACDelco recommends checking a vehicle s belts and hoses regularly about every six months Check belts for signs of wear such as cracking splitting and slipping or squealing Worn belts should be replaced Also check belt tension and tighten or replace belts with excessive play Check for degradation of hoses by using your fingers and thumb not your whole hand to check for hose weakness Most hose failures occur near the clamps or connectors Make sure the engine Is cool before checking a coolant hose ACDelco belts are constructed using only high grade materials to ensure long service life and reduce tension loss Plus ACDelco coolant hoses are manufactured with specially blended materials to resist electrochemical degradation which is the leading cause of hose failure Batteries A slow cranking engine during the sum mer could indicate the battery is growing weaker Extremes in temperature during the winter months as well as battery age and cranking power all affect the ability of the battery to start the vehicle Also check for corrosion around the terminals and make sure cables are securely fastened ACDelco s Professional Battery and 60 Series Car and Truck Battery offer long lasting maintenance free performance Tires Encourage your cus tomers to make it a habit of chec
16. es Some fuel marketers have already joined although not all fuel marketers will offer Top Tier Detergent Gasoline Once fuel marketers make public announcements a list of all fuel mar keters meeting Top Tier standards will be made available Here s a list of gaso line brands that currently meet Top Tier standards e Chevron Chevron has markets in 29 states in the West Southwest and South e QuikTrip QuikTrip not to be con fused with Kwik Trip operates con venience stores and travel centers in nine states in the South and Midwest Make an Impact with Customers On Hold The phone rings in your service center What are the odds that you ll have to place the customer calling in on hold According to AT amp T seven out of 10 business calls are placed on hold But if you place the customer on hold how can you sell yourself to those on the other end of the phone line in order to avoid a hang up After all studies show that almost 60 of callers will hang up after being placed on hold It s Important that you take care of the customers you re working with in your service center However that doesn t mean you can t get your message across quickly and professionally to potential cus tomers who are on hold ACDelco has teamed up with American Impact Media Corp to offer Total Service Support TSS participants on hold messages that help sell your business while customers wait on hold An on hold message IS an aud
17. he past several years moving from the conven tional spark plugs that were used for decades to the precious metal plugs of platinum and iridium Fir PANE ey Here are a few questions your customers might have about the newest high per formance spark plugs What is iridium Iridium is a precious silver white metal that is one of the densest materials in the world The natural properties of iridi um with a melting point approximately 700 degrees Celsius higher than plat inum enables the plug to spark with exceptional efficiency Many scientists believe that iridium which is found in the clay boundary layer of the Earth is the result of an asteroid that hit Mexico s Yucatan Peninsula approximately 50 million years ago The dust cloud that followed which was bad news for the dinosaurs had a global distribution of impact material that provid ed the basis for the deposits of iridium rich clay Iridium is found all over the world in this clay layer However its use in prod ucts is still being developed In addition to spark plugs iridium is used in cellular phones and sunglasses Wha s different about iridium spark plug design The small size design of the center and ground electrodes of ACDelco s iridium spark plug reduces voltage requirements and provides enhanced flame spread which increases combustion efficiency ignition system life and durability Due to its dense composition the iridi um tipped cen
18. io recording that mixes licensed music with pro fessionally recorded messages that play continuously while your callers are on hold Having a message on hold system reduces call abandonment by almost 90 and increases customers hold time by over 500 There are many benefits with on hold messages e Tell your customers you care about them and appreciate their business Introduce new products while promoting a professional image Discourage hang ups when callers are put on hold When customers are put on hold make the wait worthwhile The customized on hold messages are produced by American Impact which provides telecommunications and advertising ser vices to businesses worldwide They offer custom copywriting of multiple messages so each on hold message is tailored for your business Messages may provide important information about your service such as your location or years in business You may also want to promote the variety of services you offer or advertise specific products Each message will be produced with American Impact s state of the art digital message equipment using professional voice talent and their extensive library of background music Several examples of on hold messages are available on American Impact s web site For more information about how to develop and enhance the image of your service center with on hold messaging visit www americanimpact com or call Fred Spieler at American Impact at 1 800 664 6
19. k Plug Questions 6 Sports Report asas aae ee 6 Tech Tips oannaana na n 7 Getting Ready for the Cold 8 Ceramic Brake Pad Friction Material Data Online 8 New Duramax 6600 Diesel Engine Seminar Available A new ACDelco seminar on the Duramax 6600 diesel engine is now being conducted at Warehouse Distributors WD Duramax 6600 Diesel Engine SS FD 1 01 covers the unique fea tures such as the common rail fuel system of the two Duramax 6 6 liter diesel engines Regular Production Option RPO LB7 introduced in 2001 and RPO LLY introduced in 2004 The four hour seminar has been designed for experienced diesel engine technicians RPO LB7 Engine Features The RPO LB7 Duramax 6600 diesel engine was produced between the 2001 and early part of 2004 model years The LB7 diesel engine produces 300 horse power at 3100 rom and 520 lb ft of torque at 1800 rom and features a Robert Bosch direct injection fuel system that can produce fuel pressures up to a maximum of 23 000 psi The first part of the seminar reviews the following major systems of the Duramax 6600 diesel engine RPO LB7 Mechanical Lubrication Cooling Air induction and turbocharger Glow plug Crankcase ventilation Fuel e Engine management Duramax features that are highlighted include the direct injection common rail fuel system which provides an exact air fuel ratio for every combustion stroke for maximum power alo
20. king the air pressure of their tires Since air is a gas it expands when heat ed and contracts as it cools So as ambi ent temperatures drop tire pressure goes down which makes fall and winter an especially important time for checking tire pressure A good rule of thumb is that for every 10 degrees Fahrenheit in temperature change tire pressure changes about 1 osi higher as temperatures rise lower as they fall Check the tires for tread wear or any damage The tread wear should be even across the tire treads Uneven tread wear may be an indication of improper wheel alignment or worn steering or suspension components A complete under car inspection including the shocks and struts and the exhaust system can identify any compo nents that may be showing signs of wear and need to be replaced before winter s temperature extremes and poor driving conditions New Ceramic Brake Pad Friction Material Data Available Online The DuraStop ceramic brake pad friction material data for a variety of vehicle applications is now available online at acdelcotechconnect com This information also will be included in the latest 2004 ACDelco Catalog Click on the What s New tab to access a link to the friction material data which is available in a PDF format that can be downloaded printed and saved for quick and easy reference ii ig AEE JAANE This supplemental information should be used as a reference until you recei
21. ndition is intermittent and nor mal diagnosis does not lead to a conclu sive failure mode perform these steps Remove the Underhood Accessory Wiring Junction Block from the bracket at the right strut tower Loosen the bolt in the center of connector C2 and pull the connec tor loose Check terminal D2 for damage Location of damaged terminal in connector C2 If the terminal is damaged obtain a replacement p n 12110844 from tray 4 of the J 38125 Terminal Repair Kit Damaged terminal Typical good terminal Getting Ready for the Cold Talk To Your Customers about Fall and Winter Car Care As the weather turns colder now is a good time to remind your customers to prepare their car for the long winter ahead Many instances that leave motorists stranded are the result of poor mainte nance such as dead batteries or worn belts and hoses Recent vehicle mainte nance programs have shown that more than 70 of the vehicles that were inspected had a component that needed maintenance or repair Here are just a few maintenance items that you may want to discuss with your customers before winter sets In e Check all fluids including engine coolant antifreeze and windshield washer fluid and fill to the recom mended levels e Check for wear on all belts and hoses e Check the battery for a proper charge and the battery cable connections for corrosion e Check the tires for wear or damage e Replace the wiper blad
22. nect is published bi monthly for retail technicians to provide timely service information increase knowledge and improve the performance of the service center Publisher amp Editor Greg Baker ACDelco E mail lt gt greg baker gm com Technical Editors Mark Spencer E mail lt mark spencer sandycorp com Jim Horner E mail lt jim horner sandycorp com Desktop Publishing Greg Szpaichler MediaWurks E mail lt greg mediawurks com Write to D lt ACDelco TechConnect P O Box 500 Troy MI 48007 0500 On the Web L acdelcotechconnect com ACDelco service tips are intended for use by professional technicians not a do it yourselfer They are written to inform those technicians of condi tions that may occur on some vehi cles or to provide information that could assist in the proper service of a vehicle Properly trained technicians have the equipment tools safety instructions and know how to do a job properly and safely If a condition is described it cannot be assumed that the information applies to all vehicles or that all vehicles will have that condition All materials and programs described in this magazine are subject to change Submission of materials implies the right to edit and publish Inclusion in the publication is not necessarily an endorsement of the individual or the company TechConnect is published for ACDelco by Sandy Corporation Troy MI 2004 ACDelco All right
23. ng with the effi ciency of the four overhead valves per cylinder design and the fuel pulse shap ing strategy The common rail fuel system consists of a high pressure pump assembly a fuel filter assembly two common fuel rails each rail supplies fuel to four injectors hence the name common rail a high pressure junction block with a pressure limiting valve and a fuel pressure sensor and a Fuel Injection Control Module FIC The common rail fuel system has sev eral advantages over more traditional fuel systems such as fuel injection pressure that is independent of engine speed and load as well as lower noise and less emissions due to pilot fuel injection pres sure Pilot injection uses a small amount of fuel that is injected at engine speeds below 2 500 rom followed immediately by normal injection RPO LLY Engine Features The second part of the seminar covers the Duramax 6600 diesel engine RPO LLY which began production in January 2004 The LLY diesel engine produces more power than the RPO LB7 engine and is also used In medium duty truck applica tions It generates 310 horsepower at 3100 rom and 590 lb ft of torque at 1600 rom In addition to more power this engine has a nearly 90 reduction in exhaust emissions for Hydrocarbons Oxides of Nitrogen and particulates The important changes made to the Duramax 6600 diesel engine RPO LLY that are covered in the seminar include e Variable nozzle turbo
24. on Step 2 Progression of fretting corrosion Step 3 Formation of oxide layer Step 4 Unstable connection Disconnecting and reconnecting the injector connector will temporarily scrape the oxides off creating a good connec tion This explains why replacing a sus pected faulty injector with a new injector appears to repair the condition But if the conditions still exist for fretting to occur it will eventually come back To ensure that fretting is not an issue apply dielectric grease to both cavities of each injector connector This provides a lubricant for the terminals as well as an oxygen barrier to guard against oxide formation The GM part number for dielectric grease in the U S is 12377900 In Canada the GM part number is 10953529 To apply the lubricant gather a small amount about the size of a BB on the end of your finger Press it into the end of the disconnected female connector making sure to cover both cavities Reconnecting the harness connection onto the injector will wipe the lubricant onto the male terminal pins Applying lubricant continued on page 3 IN THIS I Fuel Injector Cleaning 1 Duramax 6600 Diesel Engine Seminar 2 Top Tier Detergent Gasoline 3 Making an Impact with Customers On Hold 20 4 Get a Deal on a Dell 4 Buying a Business Grade Computer 4 The Mastertech CAN 5 Iridium Spar
25. s reserved Fuel Injector Cleaning from page 1 Properly applied lubricant Injector Balance Testing An important reason for balance test ing Is that It quickly and graphically indi cates the flow of each injector and per mits comparing the performance of each injector with the others The balance test determines the condi tion of the injectors on the vehicle by comparing injector pressure drops An ini tial fuel system pressure is achieved for each injector Each injector is individually pulsed with the same number of pulses for the same time duration By using two constants starting fuel system pressure and pulse width duration the differences in injector can be compared based on the fuel pressure dropped by each injector as it is pulsed The balance test procedure calls for attaching a pressure gauge to the fuel rail The gauge must be in good operating condition and capable of reading in kilo pascals kPa The reason for reading kPa instead of psi is that kPa is a much small er measuring increment which permits a much more precise measurement It takes a difference of only 20 kPa between injectors to cause a misfire 20 kPa is equivalent to 3 psi Most psi gauges do not have enough resolution to accurately represent such small changes To perform the test connect the pres sure gauge to the fuel rail pressure con nection Purge air from the gauge by opening the valve on the side of the gauge and
26. tending to do on the road Also check the brightness of the lights A dim light or slow flashing turn signal could be a sign of a weak alternator ACDelco offers over 70 000 different parts including all types of lighting and headlamps ape ben a GOGH IARSR ETE ADV PU 0025 04
27. ter electrode is 50 percent the size of a platinum electrode and 20 percent the size of a conventional nickel electrode Comparing electrodes Iridium spark plug left and a conventional spark plug The specially designed ground elec trode increases the electric field strength at the spark plug gap which also helps reduce the voltage required for sparking to begin This also aids cold starting capa bility and quick acceleration response How does iridium enhance spark plug life ACDelco iridium spark plugs improve the combustion process by requiring less voltage to spark due to its small size and the hard wearing characteristics of iridi um delivering an optimal firing perfor mance This enhances the operating efficiency of the engine for maximum performance over the life of the plug In addition the secondary micro discharge of the center electrode burns off carbon deposits as they form for superior antifouling performance This limits carbon and other foreign sub stances from coating the firing tip and impeding efficient performance A coated firing tip makes it easier for voltage to fol low along the insulator nose and leach back down into the metal shell and ground out rather than bridge the spark plug gap and fire normally What is the performance life of iridium spark plugs ACDelco iridium spark plugs are backed with a 100 000 mile limited warranty That being said there is no set rule for changing
28. tertech e Automatically determines the communication protocol e Displays OBDII system readiness test status e Displays emission related current diagnostic data e Displays freeze frame data saved by the OBDII controller e Displays Diagnostic Trouble Codes DTC stored by the OBDII controller e Clears emissions related diagnostic information e Displays oxygen sensor monitoring test results e Displays manufacturer specific test results for systems and components e Displays pending DTCs e Enables off board device to control a component of an on board system e Displays vehicle specific information In addition to basic OBDII functionality the MTS3100 Mastertech identities when multiple OBDII controllers such as engine and transmission ECUs are reporting different data for the same diagnostic data parameters and offers a variety of ways to display and store the data Multiple freeze frames of Freeze Frame data is supported for example rather than just one frame The Selectable Parameter list allows only the data selected to be displayed at the data update rate that is needed to aid diagno sis and in the preferred display format list bar chart line graph or LED If your current scan tool cannot com municate with CAN all new MTS3100 Mastertech kits come standard with the CAN Vehicle Interface Module making it the only 100 OBDI I compliant scan tool on the market today Training is minimal with CAN be
29. ve the new ACDelco Catalog When replacing brake pads keep in mind that DuraStop ceramic brake pads should be used for original equipment applications that require non metallic brake pad friction materials Gale Sola l E IES 5 E E A I PA RIE AES Gl AT l ma a Ha Bil T eed enal amt EAr eee are ck Alene ed e a ER EG ed ed bea on balir aba f EE aL a E ui tE a oe i E edip d aE i i yey i J FIE s d ni jae d PETOT T EEL m m zE 1 i meas ened i fa a oa a HERR p ali Wipers Windshield wiper blade maintenance is critical to good visibility in inclement weather Check windshield wipers for cracks or splits as well as the wiper arms and frames for damage which can be caused by automatic car washes wot Signs that wiper blades should be replaced include streaking a chattering or skipping blade a rounding of the wiping edge of the blade and split rubber ACDelco s enhanced line of wiper blades includes all season blades winter blades and heavy duty blades for all makes and models anne ier teary Vehicle Lighting During poor weather being seen on the road is as critical as seeing what s down the road Check that headlights are aimed cor rectly to enable drivers to see the road well Check that tail lights turn signals and brake lights are operating so drivers know what other vehicles are doing or in
30. y benefit from clean ing Research indicates that an injector running lean could lead to a driveability condition Injector Cleaning GM Top Engine Cleaner is an effective cleaner that won t cause damage to plas tic or metal components in the fuel injec tion system when used as Instructed The GM part number for GM Top Engine Cleaner in the U S is 12346535 It s packaged in pre measured 0 812 oz 24 ml bottles In Canada the part num ber is 992872 and It s packaged In a15 oz 443 6 ml bottle Typically the injector cleaning process is run twice to ensure thorough cleaning of the injectors For each batch of cleaning agent add two 24 ml bottles US or measure 1 6 oz 48 ml Canada into the J 35800 injector cleaning tool and top off with unleaded gasoline This will result in a 10 mixture Research shows that con centrations greater than 10 do not improve effectiveness J 35300 Fuel Injector Cleaner Follow the tool instructions when hook ing up the injector cleaner equipment It s Important to use the appropriate special tools to block the fuel feed and return lines The reason is to isolate the cleaning agent to the fuel rail only and to prevent getting it into the fuel tank which could damage the fuel pump check ball For more information about how to test and clean Multec Il injectors refer to GM bulletin 03 06 04 030A To learn more about fuel systems check out ACDelco training course FC 2
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