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FUEL SYSTEM (PUMP, CARBURETOR, TANK)

1. 52 Testing the Fuel 50 PART 6 Service Diagnosis Carburetor s q 5 imi REPAIR edm i d 55 SPECIAL TOOLS T109 22 Bending Tool T109 39 1364 Gauge Fast Idle Cam Positioning 109 29 Wire Gauge 020 Secondary Throttle Lever T109 166 1 4 Gauge Vacuum Kick Adjustment T109 31 14 Gauge Choke Unloader Auto Trans T109 31 14 Gauge Fast Idle Cam Positioning T109 173 Main Metering Jet Removal and Installation T109 238 174 Manual Trans 109 213 Tool T109 32 1X4 Gauge Fast Idle Cam Positioning T109 214 Bending Tool 134 Gauge Unloader Adjustment 109 282 14 Gauge Float T109 36 Ve Gauge Vacuum Kick Adjustment T109 2878 Elevating Legs T109 41 Bending Tool Fast Idle and Unloader C 3400 Repair Stand T109 58 Screw Driver Bit 73598 Power Bypass Jet Removal and Installation T109 59 Screw Driver Bit 73605 Bending Tool T109 80 Gauge 38 Unloader 73725 3 2 Gauge Float T109 106 7 amp Gauge Vacuum Kick Adjustment No 47 364 Drill Bowl Vent Valve Manual Trans RENE CARBURETOR ENGINE DISPLACEMENT Cu In q a die muta qua Saa TES CAR MODEL EN
2. PRIMARY THROTTLE VALVES TANG ON SECONDARY 1 THROTTLE LEVER CHOKE VALVE WIDE OPEN SLOWLY OPEN THROTTLE VALVES 64x355 Fig 19 Testing the Secondary Throttle Adjustment lodged by the free flow of fuel as the carburetor is primed Idle Speed Adjustment Curb Idle To make the idle speed adjustment the engine must be thoroughly warmed up A much more reliable idle adjustment can usually be obtained if the car has been driven a minimum of five miles For the best results it is recommended that a tachometer be used in this adjustment Before making the idle speed adjustment observe the following precautions On cars equipped with the automatie transmission loosen the nut in the sliding link of the carburetor to bellerank rod so that the stop in the transmission will not interfere with the free movement of the carburetor throttle lever 1 To make the idle speed adjustment turn the idle speed screw in or out to obtain 500 rpm On cars with air conditioning set the idle speed at 500 SECONDARY SHOE PRIMARY SHOE BEND TO ADJUST WIRE GAUGE 64x356 Fig 20 Measuring Clearance Between Closing Shoes CHOKE VALVE WIDE OPEN FAST IDLE CAM FAST IDLE SPEED ADJUSTING Nc SCREW ON LOWEST STEP OF CAM 64 358 Fig 21 Fast Idle Speed Adjustment On the Engine rpm Be sure the choke valve is fully open and that the fast idle adjusting screw is n
3. w Fig 9 Removing the Secondary Venturi venturi to the main body These venturi are not interchangeable side for side and it is suggested that the pump side venturi be marked for identification Remove the venturi as shown in Figure 9 Discard the gaskets The pump side venturi is numbered 678 The opposite one numbered 679 5 Lift out the velocity valves and counterweights as shown in Figure 10 6 Using Tool T109 58 remove the accelerator pump inlet check ball and cage as shown in Figure 11 7 Remove the idle mixture adjusting screws and springs from the throttle body casting The carburetor now has been disassembled into two units namely the air horn and the main throttle body casting The component parts of each unit have been disassembled as far as necessary for cleaning and inspection Cleaning the Carburetor Parts The recommended solvent for gum d ACCELERATOR PUMP WELL 63x614 Fig 10 Removing the Velocity Valves FUEL AND INDUCTION SYSTEM 14 45 ACCELERATOR PUMP AE 63x615 Fig 11 Removing the Pump Inlet Check Ball Cage natured alcohol which is easily obtainable However there are other commercial solvents such as Metal clene which may be used with satisfactory results IMPORTANT If the commercial solvent or cleaner recommends the use of water as a rinse it should be HOT After rinsing all trace of water must be blown from the various passages with a
4. 12 Remove the two bolts that attach the left hand by pass pipe to the lower chamber i 13 Remove the two bolts that attach the left hand exhaust manifold elbow to the lower chamber Discard the gaskets 14 Remove the four bolts that attach the intake manifold to the right bank cylinder head Remove the exhaust passage crossover cover 15 Lift the intake manifold and carburetor from the engine as an assembly 16 Remove the nuts that attach the carburetor to the intake manifold Remove the carburetor 17 Remove the eight attaching bolts that hold the right fender shield access plate to the fender shield then slide plate out of engine compartment 18 Remove the two bolts that attach the right hand exhaust by pass pipe to the lower chamber 19 Remove the two bolts that attach the right hand exhaust manifold elbow to the lower chamber Discard the gaskets 20 Remove the four bolts that attach the intake manifold to the left bank cylinder head Remove the exhaust passage crossover cover 21 Lift the manifold and carburetor from the engine as an assembly 22 Remove the nuts that attach the carburetor to the intake manifold then disconnect the automatic choke rod from the lever Remove the carburetor Installation When installing the intake manifolds be sure and use new gaskets and be sure all mating surfaces are smooth and clean To install the left hand intake manifold refer to Figure 2 then proceed
5. The carburetors are equipped with a rubber tipped fuel inlet needle The rubber tip is flexible enough to make a good seal on the needle seat and to give in creased resistance to flooding The use of the rubber tipped needle requires a new procedure in adjusting the float setting Care should be taken to perform this operation accurately in order to secure the best performance and fuel economy 1 To correctly set the float height when the car buretor is being overhauled install the floats with the fulcrum pin and pin retainer in the main body 2 Install the rubber tipped needle seat and gas ket in the body and tighten securely 3 Invert the main body so that the weight of the float only is forcing the needle against the seat Hold finger against the retainer to fully seat the fulerum pin 4 Using Tool T109 282 or a T scale measure the float as shown in Figure 8 There should be 4 inch from the surface of the fuel bowl to the crown of each float at the center If an adjustment is necessary hold the floats on the bottom of the bowl and bend the float lip toward or away from the needle Recheck the 14 inch setting again and repeat the lip bending operation as re quired CAUTION When bending the float lip do not allow the lip to push against the needle as the rubber tip can be compressed sufficiently to cause a false setting which will affect correct level of fuel in the bowl BBD CARBURETOR 14 19 NOTE Af
6. The five conventional systems are two float sys tems two low speed systems primary side only two high speed systems one accelerator pump sys tem and one automatic choke control system SERVICE PROCEDURES 1 SERVICING THE CARBURETOR Dirt dust water and gummy deposits are some of the main causes for poor carburetor operation How ever proper cleaning and the installation of new parts where required will return the carburetor to its originally designed performance When overhauling the AFB carburetor several items of importance should be observed to assure a good job The carburetor should be carefully disassembled and all parts except the choke diaphragm assembly should be cleaned in a suitable solvent and inspected for wear or damage Air pressure only should be used to clean the various orifices and channels Replace questionable parts with new ones 2 DISASSEMBLING THE CARBURETOR Fig 1 1 Place the carburetor assembly on repair stand Tool C 3400 or T 109 287S elevating legs 2 Remove the hairpin clip that attaches the fast idle connector rod to the choke lever Disengage rod from lever then swing rod at an arc until it can be disengaged from the fast idle cam 3 Remove the retainer and spring that holds the throttle connector rod in the center hole of the accel erator pump arm Remove the hairpin clip that at taches the lower end of rod in the primary throttle shaft lever Disengage rod from
7. 7 THESE SURFACES MUST BE PARALLEL FUEL BAFFLE lt FUEL BAFFLE 64x343 MINIMUM CLEARANCE WITHOUT BINDING Fig 9 Measuring the Float Alignment NOTE Be sure the marked float is installed on the pump side of the air horn 6 After the floats have been installed test the float alignment level and drop settings as follows Float Alignment Setting 1 Sight down the side of each float shell to de termine if the side of the float is parallel to the outer edge of the air horn casting as shown in Figure 9 2 If the sides of the float are not in alignment with the edge of casting bend the float lever by applying pressure to the end of the float shell with the fingers while supporting the float lever with the thumb NOTE To avoid damage to the float apply only enough pressure to bend the float lever 3 The arms of the float lever should be parallel to the inner surfaces of the lugs or the casting Float Level Setting 1 With the air horn inverted the air horn gasket FLOAT GASKET IN PLACE Fig 10 Measuring the Float Height GASKET IN PLACE EACH FLOAT 64x345 Fig 11 Measuring the Float Drop in place and the float needle seated slide the float gauge Tool T109 106 74 between the top of the float at outer end and the air horn gasket as shown in Figure 10 2 Measure the other float in the same manner If an adjustment is necessary bend the float arm using Too
8. Bowl Vent Valve Setting Fast Idle Speed and Cam Position Adjustment The fast idle engine speed adjustment should be made on the vehicle as described in the Fast Idle Speed Adjustment On the vehicle paragraph of this group however the Fast Idle Cam Position Ad justment can be made on the bench as follows 1 With the fast idle speed adjusting screw con tacting the lowest step on the fast idle cam as shown in Figure 17 move the choke valve toward the closed position with light pressure Insert a 1 4 inch drill or gauge Auto Trans 1 inch Manual Trans be tween the choke valve and the wall of the air horn 2 An adjustment will be necessary if a slight drag is not obtained as the drill or gauge is being removed 3 an adjustment is necessary bend the fast idle rod at the upper angle using Tool T109 213 until the correct valve opening has been obtained Vacuum Kick Adjustment This test can be made ON or OFF the vehicle To make the vacuum kick adjustment the vacuum diaphragm must be energized either a distributor testing machine with a vacuum source or vacuum supplied by another vehicle To make this adjust ment proceed as follows 1 With the engine Not running open the throttle valves far enough to allow the choke valve to be moved to the closed position 2 Disconnect the vacuum hose from the dia phragm and connect the hose from the vacuum supply as shown in Figure 18 A minimum of 10
9. GAUGE OR DRILL AT WIDEST CHOKE OPENING LIGHT CLOSING PRESSURE AGAINST FAST IDLE VALVE CAM a p 74 ADJUSTING hy FAST IDLE ROD SCREW ON a BEND AT LOWEST STEP THIS POINT AND AGAINST FACE OF NEXT FAST IDLE CAM STEP N ADJUSTING SCREW SCREW 64x233 Fig 17 Fast Idle Speed Cam Position Adjustment WWC3 CARBURETOR 14 11 LIGHT CLOSING PRESSURE GAUGE OR DRILL APPLIED TO CHOKE SHAFT AT WIDEST CHOKE OPENING TO VACUUM SOURCE MINIMUM OF 10 INCHES OF VACUUM REQUIRED ON DIAPHRAGM CHOKE OPERATING LINK DIAPHRAGM STEM PLUNGER RETRACTED 64x234 Fig 18 Measuring the Choke Vacuum Kick Setting inches of mercury HG will be required 3 Insert a inch drill or gauge Manual Trans mission or an 1144 inch Automatic Transmission between the choke valve and the wall of the air horn Refer to Fig 18 Apply a slight closing pressure to the choke shaft to hold the drill or gauge in position 4 An adjustment will be necessary if a slight drag is not obtained as the drill or gauge is being removed The adjustment of this opening will require the removal of the choke operating link CAUTION DAMAGE TO THE DIAPHRAGM AND THE CHOKE LEVER SLOT CAN RESULT IF THE LINK IS NOT REMOVED FOR THE BENDING OP ERATION 5 Remove the clip and disengage the choke opera ting link from the choke lever then disengage the link from the dia
10. Tighten clamps securely 14 Reconnect the throttle linkage at both retor and bell crank to accelerator shaft 15 Reinstall the high tension coil wire _ 16 Reconnect the vacuum line between the car buretor and distributor 17 Reconnect the fuel line between the left and right hand carburetors RIGHT BANK CARBURETOR ROD CHOKE CABLE r ADJUSTING LINK D LOCKING BOLT AND NUT cue o ACCELERATOR SHAFT THROTTLE SHAFT LEVER ot ADJUSTING LINK rere Q LOCKING BOLT MS NOUO T lt SY ACCELERATOR SHAFT AND BRACKET ADJUSTING LINK TZ BELLCRANK TO TRANSMISSION ROD cue 7 gf TRANSMISSION THROTTLE CONTROL LEVER ACCELERATOR LEFT BANK SHAFT TO NP KICK DOWN POSITION CARBURETOR ROD ieee Lu WIDE OPEN THROTTLE POSITION ADJUSTING LINK 519 15 SPRING 2 A IDLE POSITION CHOKE CABLE 1 CLIP BELLCRANK ACCELERATOR SHAFT TO THROTTLE SHAFT LEVER ROD ACCELERATOR SHAFT TO BELLCRANK ROD A LockiING NUT ADJUSTING LINK GROMMET LOCKING NUT ACCELERATOR PEDAL TO SHAFT ROD INSTRUMENT PANEL a o dia B LOCKING NUT _ INSTRUMENT PANEL ACCELERATOR SHAFT BRACKET ACCELERATOR PEDAL TO SHAFT ROD ACCELERATOR PEDAL Tio je SIDE VIEW 63x569 Fig 3 Throttle Linkage Schematic 18 Reconnect the fuel line between the fuel pump and the left hand carburetor 19 Reinstall the right and left carburetor
11. crossover passage cover over the passage then install the manifold attaching bolts finger tight 8 Slide a new gasket between the right hand ex haust manifold elbow and the lower chamber of the intake manifold Install attaching bolts finger tight 9 Slide a new gasket between the right hand ex haust by pass pipe and the lower chamber Install attaching bolts and tighten to 10 foot pounds Tighten the elbow attaching bolts to 10 foot pounds and the intake manifold bolts to 50 foot pounds 10 Slide the right hand fender shield access plate into position against fender shield Install bolts and tighten AIR CLEANER ASSY ee WING NUT c AIR CLEANER STUD VACUUM CONTROL CARBURETOR ASSEMBLY ES INTAKE MANIFOLD LEFT EXHAUST CROSSOVER COVER N EXHAUST MANIFOLD HEAT INLET ELBOW 60x166 Fig 2 Fire Power Manifold Disassembled 14 40 FUEL AND INDUCTION SYSTEM 11 Place the air conditioning compressor and brackets in position if so equipped and install attach ing bolts Tighten securely Refer to the Air Condi tioning Group 24 for method of recharging the sys tem 12 Reconnect the Power Steering hoses to the pump if so equipped Refer to Power Steering Group 19 for method of bleeding air out of the system 13 Slide the equalizer tube clamps and couplings over the manifold tubes Slide either coupling outward far enough to firmly engage the manifold
12. off in the shaft Remove staking with a file 2 Slide the new valve or valves down into the bore and through the slot in the shaft Install new serews but do not tighten 3 Hold the valves in place with the fingers pressing on the high side of valves Tap the valves lightly with a screwdriver to seat in the throttle bores 4 Holding the valves in this position tighten the screws securely and stake by squeezing with pliers 5 Install the two idle mixture adjusting screws and springs in the throttle body The tapered portion of the screws must be straight and smooth If the tapered portion is grooved or ridged new idle mixture screws should be installed to insure having correct idle mixture control DO NOT USE A SCREW DRIVER The adjustment should be made with the fingers Turn the screws lightly against their seats then back off one full turn for approximate setting 6 Install the velocity valves and counterweights Refer to Fig 10 i 63x617 Fig 13 Installing the Pump Discharge Check Needle NO FUEL SHOULD PASS THE DISCHARGE CHECK NEEDLE ACCELERATOR PUMP PLUNGER SHOULD EMIT HE FROM INLET PASSAGE 63x618 Fig 14 Testing the Accelerater Pump Check Ball and Discharge Needle 7 Place new secondary venturi gaskets in position then install the secondary venturi Refer to Fig 9 Install screws and tighten securely Be sure each is located in its original
13. air Examine all choke parts for wear or damage Worn or danraged parts must be replaced with new in order to insure proper choke operation When instaling the well type choke unit make certain that the coil housing does not contact the 14 36 AFB CARBURETOR sides of the wall in the intake manifold Any contact at this point will affect operation 6 CLOSED CRANKCASE VENT SYSTEM The closed crankcase ventilator valve is located in the crankcase vent tube cap and is connected to the carburetor throttle body via a rubber tube See Fig 22 The function of the valve is to regulate the flow of unburned hydrocarbons from the crankcase and return them to the intake manifold From here they enter the combustion chamber and then exit via the exhaust system as completely burned exhaust prod ucts For servicing procedures of this system refer to the Engine section Group 9 7 THROTTLE LINKAGE To adjust the throttle linkage refer to Figure 23 for the complete instructions 3 ASSEMBLE TRANSMISSION CONTROL LINKAGE PARTS IN PLACE BUT DO 7 NOT ASSEMBLE TRANSMISSION ROD BALL SOCKET 5 TO BALL END APPLY A THIN FILM OF MS 3701 LUBRICANT TO THE ACCELERATOR SHAFT T WHERE IT TURNS IN THE BRACKET DISCONNECT CHOKE 2 AT CARBURETOR OR BLOCK CHOKE VALVE IN FULL OPEN POSITION OPEN THROTTLE SLIGHTLY TO RELEASE FAST IDLE CAM THEN RETURN CARBURETOR TO CURB IDLE 8 HOLD THE TRANSMISSION LEVER 8 FORWARD AGAINST ITS STOP A
14. and intake manifold a Correct b Replace since this problem ean be corrected by use of proper choke assembly e Correct or replace d Correct a Replace or correct 14 58 DIAGNOSIS FUEL SYSTEM Condition us Possible Cause Correction EXCESSIVE STALLS AFTER COLD START Choke System Lean a Check items under Poor a Refer to page 56 for correction Starting Choke Valve Fails to Close b Choke vaeuum dia b Adjust to Specification phragm adjustment lean Engine Output Low a Fast idle speed low a Adjust to specification b Fast idle cam position b Adjust to specifieation adjustment incorrect c Engine lubrication oil of e Recommend 5W 20 incorrect viscosity Carburetor Lean Curb idle set very lean a Adjust b Air leak bypassing the b Repair carburetor
15. arm and lever then remove from carburetor 4 Remove the vacuum hose between the carburet or body and the vacuum diaphragm 5 Remove the clip from the choke operating link and disengage the link from the diaphragm plunger stem and the choke lever Refer to Fig 1 6 Remove the vacuum diaphragm and bracket as sembly and place to one side to be cleaned as a separate item liquid cleaner may damage the dia phragm material 7 Remove the screws attaching the step up piston and rod cover plates NOTE Hold cover down with a finger to prevent the piston and rods from flying out STEP UP PISTON PISTON ROD STEP UP PISTON SPRING qi SCREW i COVER PLATE PISTON Fig 2 Removing Step up Pistons and Rods SS SPRING 64x34 8 Lift off the plates and slide the step up pistons and rods out of the air horn as shown in Figure 2 Remove the step up piston springs 9 Remove the ten screws that attach the air horn to the main body 1 scr w in hole in air horn Lift air horn straight up and away from the main body NOTE When removing air horn use care so as not to bend or damage the floats 10 Remove the accelerator pump plunger lower spring from the pump cylinder Disassembling the Air Horn Place the air horn in an inverted position on the bench to protect the floats 1 Using a suitable tool remove the float fulcrum pins left and right and lift the floats up and out of bosses on
16. as follows 1 Place the carburetor in position on the mount ing pad of the intake manifold and engage the choke control Install the carburetor mounting nuts and tighten 2 Place the intake manifold assembly in position on the right hand bank cylinder head Place the ex haust crossover passage cover over the passage then install the manifold attaching bolts finger tight 3 Slide a new gasket between the left hand ex haust manifold elbow and the lower chamber of the intake manifold Install attaching bolts finger tight 4 Slide a new gasket between the left hand ex haust by pass pipe and the manifold lower chamber Install the attaching bolts and tighten to 10 foot pounds Tighten the elbow attaching bolts to 10 foot pounds and the intake manifolds bolts to 50 foot pounds CLAMP COUPLING CLAMP EQUALIZER TUBE EXHAUST CROSSOVER COVER GASKET REINFORCEMENT GASKET SEALER AS REQUIRED ec V FUEL AND INDUCTION SYSTEM 14 39 5 Slide the left hand fender shield access plate into position against fender shield Install bolts and tighten If both intake manifolds were removed continue to install the right hand manifold as follows 6 Place the carburetor in position on the mount ing pad of the intake manifold and connect the choke control Install the carburetor mounting nuts and tighten 7 Place the intake manifold assembly in position on the left hand bank cylinder head Place the exhaust
17. idle connector rod with the fast idle cam then swing in an arc to lock in eam Slide other end of rod into the choke shaft lever and secure with hairpin clip Installing the Vacuum Diaphragm 1 Install the vacuum diaphragm assembly on the main body and tighten the attaching screws securely 2 Install the choke operating link in position be tween the diaphragm plunger stem and the choke lever Install the clip to secure 14 32 AFB CARBURETOR 8 Inspect the vacuum diaphragm fitting and re move any dirt or foreign material which could clog the passage Inspect the rubber hose for cracks before placing it on the eorrect throttle pony fitting Refer to Fig 1 Do not connect the vacuum hose to the diaphragm fitting until after the vacuum kick adjustment has been made See Carburetor Adjustments 4 CARBURETOR ADJUSTMENTS The adjustments are made with the carburetor on the bench for ease of working and should be made in the following order Fast Idle Speed and Cam Position Adjustment The fast idle engine speed adjustment should be made on the engine as described in the Fast Idle Speed Adjustment On the engine paragraph of this group however the Fast Idle Cam Position Adjust ment can be made on the bench 1 Open the throttle valves far enough to allow the fast idle speed adjusting screw to clear the fast idle cam 2 Insert a 549 inch drill or gauge between the choke valve and the air horn wall as shown
18. idle mixture control NOTE Do not use a screw driver The adjustment should be made with the fingers Turn the idle mixture adjusting screws lightly against their seats and back off one full turn for an approxi mate adjustment 4 Place the new secondary venturi gaskets in position bleed hole in top toward the center of the carburetor install the secondary venturi pump and choke side by lowering straight down on the gaskets Install the attaching screws and tighten securely NOTE Be sure all the metering holes and vent tubes are clean in both the primary and secondary venturi 5 Place new primary venturi gaskets in position then install the primary venturi pump and choke side by lowering straight down on the gaskets See Fig 5 Install attaching screws and tighten securely 6 Install the primary and secondary main meter ing jets using Tool T109 58 See Fig 4 cns jets securely 7 Install the accelerator pump intake check ball assembly in position in the carburetor bowl Tighten securely using Tool 109 59 Accelerator Pump Test 1 Pour clean gasoline into the carburetor bowl approximately 12 inch deep Remove the accelerator pump plunger from the jar of gasoline Flex the leather several times then slide it on the pump cylinder 2 Install the accelerator pump discharge check needle in the discharge passage Raise the pump plunger and press lightly on the plunger shaft to ex pel air from
19. inlet check ball is located at the bottom of the plunger well 5 Install new gaskets on the venturi cluster and install in position in the main body Fig 4 Install the idle bleed screws and tighten securely Test pump discharge by pressing pump plunger down Two fine streams of fuel should be forced from the cluster If either stream is restricted or diverted remove cluster and reclean After test pour the fuel from the bowl and remove pump plunger 6 Install the main metering jets and gaskets Tighten securely Fig 3 7 Before installing the step up piston be sure the step up rods are able to move freely each side of the vertical position as shown in Figure 7 The step up rods must be straight and smooth 8 Slide the step up piston gasket down into posi tion in the piston well then install the step up piston springs step up piston and rods Carefully guide the step up rods into the main metering jets Fig 2 Install the retaining screw and tighten securely Check piston for free operation in the well A step up piston stuck in the Up position will cause a rich mixture at part throttle whereas a piston stuck in the Down position will cause a lean mixture at wide open throttle and poor acceleration STEP UP RODS MUST MOVE FREELY 60x106 Fig 7 Step Up Rods Free Play ONLY WEIGHT OF FLOAT AGAINST NEEDLE 60x107A Fig 8 Measuring the Float Setting Measuring the Float Setting Off the Vehicle
20. linkage shaft or related parts corroded bent or dirty such that the system is not entirely free to move from the open to the closed position d Choke valve improperly seated P e Air cleaner interferes with choke shaft or linkage e d e a b d e a a b e d e Test the fuel level in the carburetor Make the necessary adjustment to obtain float level Clean and inspect the needle valve and seat If found to be in a questionable condition replace the complete assembly and test the fuel pump pressure Refer to Specifications for correct fuel pump pressure Test the fuel pump pressure If the pressure is in excess of recommended pressure refer to Specifica tions replace fuel pump Remove and clean the air cleaner Disassemble the earburetor Replace leaking float Test the float level and correct as necessary to the proper level Adjust the fioat level as necessary to secure the proper level Test the fuel pump pressure Refer to Specifications for recommended pressure If pressure Is in excess of recommended pressure replace the fuel pump assembly Disassemble the carburetor Replace the worn metering jet using a new jet of the correct size and type Instruct owner Adjust Replace assembly Repair clean or replace Reseat valve Rotate cleaher to correct position DIAGNOSIS FUEL SYSTEM 14 57 SERVICE DIAGNOSIS C
21. normal car opera tion between the speeds of 15 and 30 miles per hour If it has been determined however that a new shaft or valves is to be installed adhere to the following instructions 2 Mark the position of the throttle valves in the bores Be sure the idle speed screw is backed off 3 Remove the screws that hold the throttle valves to the shaft and slide the valves out of the bores IDLE TRANSFER PORTS SPARK ADVANCE THROTTLE VALVES VENT HOLE 64 x 331 Fig 5 Ports in Relation to Throttle Valves BBD CARBURETOR CAUTION These screws are staked on the op posite side and care should be used at removal so as not to break off in the shaft Remove the staked end of the screws with a file 4 Slide the throttle shaft and lever out of the body 5 Install new throttle shaft and lever 6 Install throttle valves in their respective bores with the valve number toward the manifold Install new screws but do not tighten Hold the valves in place with the fingers pressing on the high sides of the valves Tap the valves lightly with a screwdriver to seat in the throttle bores Tighten the screws securely and stake by squeezing with pliers T Install the idle mixture screws and springs in the throttle body The tapered portion must be straight and smooth If the tapered portion is grooved or ridged new idle mixture screws should be installed to insure having correct idle mixture control DO
22. place I Be sure all the metering holes and vent tubes are clean and clear in both the primary and secondary venturi 8 Place new primary venturi gaskets in position then install the primary venturi Refer to Fig 8 Install screws and tighten securely Be sure each is located in its original place 9 Install the primary and secondary main meter ing jets in the main body Tighten securely using Tool T109 58 Refer to Fig 7 Tighten securely Accelerator Pump Test 1 Pour clean gasoline into the float bowl pump side approximately 1 2 inch deep Remove the pump plunger from the jar of gasoline and flex the leather several times then slide down into the pump well 2 Install the accelerator pump discharge check needle in the discharge passage as shown in Figure 13 Raise the pump plunger and press lightly on the plunger shaft to expel air from the pump passage 3 Using a small clean brass rod hold the dis charge check needle firmly down on its seat Again raise the plunger and press downward No fuel should be emitted from the discharge or the intake sage as shown in Figure 14 If fuel does emit from the intake passage remove the intake check ball and cage and reclean Fuel leakage at the discharge check needle indicates the presence of dirt or a damaged check needle Clean again and install a new needle Retest as described above If either the intake check ball or discharge check needle leaks after the
23. the new throttle shaft and lever in the throttle body NOTE The idle speed adjusting screw must be backed off when seating the valves in the following operation T Slide the valves down into position with the notches in the valves at the ports Install new screws but do not tighten Hold the valves in place with the fingers pressing on the high side of valves 8 Tap the valves lightly with a screwdriver to seat in the throttle bores Holding the valves in this position tighten the screws securely and stake by squeezing with pliers 9 Install the two idle mixture adjusting screws and spring in the throttle body The tapered portion must be straight and smooth If the tapered portion is grooved or ridged a new idle mixture adjusting screw should be installed to insure having correct idle mixture control DRIVE PLUGS POWER BY PASS JET GASKET FULCRUM PIN SPRING FUEL INLET NEEDLE VALVE SEAT AND GASKET FLOAT BAFFLE ad FULCRUM PINS FLOAT ATTACHING SCREWS VENTURI CLUSTER a GASKET DISCHARGE es CHECK BALL INLET CHECK BALL j PUMP MAIN BODY MAIN METERING JETS PASSAGE PLUGS 60x343 Fig 11 Main Body Disassembled View DO NOT USE A SCREWDRIVER The idle mixture screw adjustment should be made with the fingers Turn the screws lightly against their seats then back off one full turn for an approximate setting 5 MAIN BODY ASSEMBLY Fig 11 1 Place a new gasket on th
24. wire brush Shake dirt or other foreign material from the stem side of the diaphragm Depressing the dia phragm plunger stem to the retracted position will BBD CARBURETOR 14 17 provide an additional hole for the removal of dirt Compressed air can be used to remove loose dirt but should not be connected to the vacuum inlet fitting IMPORTANT If the commercial solvent or cleaner recommends the use of water as a rinse it should be HOT After rinsing all trace of water must be blown from the passages with air pressure It is further advisable to rinse all parts in clean kerosene or gasoline to be certain no trace of moisture remains Never clean jets with a wire drill or other mechani cal means because the orifices may become enlarged making the mixture too rich for proper performance 3 INSPECTION AND REASSEMBLY Throttle Body 1 Inspect the throttle shaft and throttle body for excessive wear If either or both are worn to the point where the carburetor operation will be affected replace as required During manufacture the location of the idle trans fer port and the spark advance control ports to the throttle valve is carefully established for one par ticular assembly Fig 5 If a new shaft should be installed in an old worn throttle body it would be very unlikely that the original relationship of the ports to the valves would be obtained Changing the relationship of the valves to the ports would adversely affect
25. 3 URN COVER STEP UP ROD SCREW JET OLD TYPE SOY JET NEW TYPE 1 171 Fig 12 Step up Piston Rod and Jet The change from the low speed best fuel economy road load mixtures to the richer wide open throttle pull mixtures is accomplished in two steps This has made it possible to secure best low speed fuel economy without sacrificing performance in the intermediate speed range To do this there is a new step up piston and spring assembly new metering rods with three diameters and new style primary metering jets as shown in Figure 12 5 Slide the step up piston springs into the piston cylinders followed by the step up pistons and step up rods Install the cover plates and attaching screws while holding the step up pistons down in position Tighten screws securely 6 Slide the choke piston into its cylinder in the air horn guiding the link into the slot in the choke valve lever Align hole then install attaching cotter pin Place a new welch plug over the cylinder opening and secure by rapping with a hammer Be sure the sealing surface is clean Check the fit of the choke valve in air horn The valve should be evenly spaced on all sides Loosen screws and reposition if neces Sary 7 Engage the throttle connector rod with the primary throttle shaft lever and install hairpin clip Install the other end of the connector rod in the pump arm and secure with clevis clip 8 Engage the lower end of the fast
26. 3 with Firepower 340 VY 1 with Imperial V 8 Ve 19 1 4 134 089 067 465 035 16 165 16 160 16 173 cv W3ISAS 1903 SPECIFICATIONS Continued ADJUSTMENTS Accelerator Pump 1 xw Accelerator Pump Travel Blades Fully Closed Je Ae Accelerator Pump Top of Plunger to Air horn Ae 74e Ae Float Setfing 3o 3 2 7o Ya Z Float Drop isses IRI 34 Ya 34 Bowl Vent Valve Curb Idle Vie Ve Yo Vacuum Kick Drill 5 Fo Wa Wa Vs Vs Choke 154 A 38 38 Idle Mixture Screws Turns Open 1 19 34 1 2 1 2 1 2 Idle Speed RPM Curb Idle 500 500 500 500 700 500 Air Conditioning on 500 500 500 500 500 500 Fast Idle Speed pe 600 700 700 700 1400 700 Fast Idle Cam Position Adjustment 1 4 Ua 1964 Secondary Throttle Lever Adjustment 2a 2 Secondary Throttle Lockout Adjustment 020 020 020 Velocity Valve Pp aaa Ca aaa eva Lue E S Free CHOKE DIN Weil Well Well Hand Well Control i usus cua suu rwr A e Las Thermo
27. 87S in the mounting flange holes in the throttle body These legs are used to protect the throttle valves from damage and to provide a suitable base for working 2 Remove the hairpin clip that holds the pump rod in the center slot of the pump arm Remove rod from slot and disengage from the throttle lever 3 Remove the hairpin clip that hold the fast idle rod in the fast idle cam Disengage rod from cam then rotate rod to disengage from choke lever 4 Remove the three short air horn attaching screws then remove the two long air horn attaching screws Install two short screws through the main body into the throttle body to hold the bodies to gether Fig 3 5 Remove the vacuum hose between the carburet or air horn and the vacuum diaphragm 6 Remove the clip from the choke operating link and disengage the link from the diaphragm plunger stem and the choke lever Refer to Fig 1 7 Remove the vacuum diaphragm and bracket as sembly and place to one side to be cleaned as a special item A liquid cleaner other than mineral AIR HORN FAST IDLE ROD Axa HAIRPIN CLIP AIR HORN SCREWS H AIR HORN SCREWS SHORT LONG ACCELERATOR PUMP PLUNGER AIR HORN TO MAIN BODY GASKET ACCELERATOR PUMP ROD HAIRPIN CLIP MAIN TO THROTTLE BODY GASKET 63x484 Fig 2 Carburetor Assembly Disassembled View WWC3 CARBURETOR POWER PISTON STEM ACCELERATOR PUMP PLUNGER FULCRUM PIN SP
28. ARGE CHECK BALL APPROX 1 2 INCH OF FUEL IN THE BOWL WP NO FUEL TO BE EMITTED FROM PUMP E act INTAKE PASSAGE ye 63 x 495A Fig 14 Testing Accelerator Pump Discharge and Inlet Check Balls ACCELERATOR PUMP PLUNGER WWC3 CARBURETOR 14 9 age that would not allow the ball to seat properly 4 Reinstall the check ball and test again If still leaking place a piece of drill rod down on the check ball and rap sharply with a hammer Remove the old check ball and install a new one Then retest This operation forms a new ball seat in the car buretor casting 5 Install the venturi cluster gasket and slide the venturi cluster down into position Fig 6 Install attaching screws and tighten securely Again depress the accelerator plunger A clear straight stream should emit from each jet orifice If streams are not identical if either one is restricted or diverted remove venturi cluster and reclean After test pour gasoline from the bowl and remove the pump plunger 6 Check the float for leaks or damage If satis factory for further service install in position in the bowl 7 Assemble the fuel inlet needle valve seat and gasket then insert in the main body Tighten se curely If the needle valve is ridged or grooved or badly worn a new synthetic rubber tipped fuel inlet needle valve assembly should be installed Setting the Float Height The carburetor is equipped with a synthetic rubber tippe
29. BURETOR ASSEMBLY CRANKCASE VENT VALVE Fig 22 Closed Crankcase Vent System allow the throttle to close Return the choke valve to the wide open position 3 The fast idle speed adjusting screw should be contacting the lowest step on the fast idle cam as shown in Figure 21 4 With the engine warmed up to the normal operating temperature turn the fast idle speed ad justing screw in or out to secure 700 rpm Reposition the cam and throttle affer every fast idle speed screw adjustment 5 AUTOMATIC CHOKE Well Type To function properly it is important that all parts be clean and move freely Other than the occasional cleaning the automatic choke control requires no servicing It is very important however that the choke control unit moves freely at the thermostatic coil spring housing and at the choke shaft Move the choke rod up and down to check for free movement of the coil housing on the pivot If unit binds a new unit should be installed The Well Type Choke Control Unit is serviced only as a complete unit Do not attempt to repair Do not lubricate any parts of the choke or control unit since this causes dirt accumulation which would result in binding of the choke mechanism Do not attempt to change the calibration setting Refer to specifications This is pre determined and should it be changed improper action would result Clean all choke parts using a suitable solvent and then blow dry with compressed
30. FUEL SYSTEM 14 1 GROUP 14 FUEL SYSTEM PUMP CARBURETOR TANK CONTENTS PART 1 WWC3 Series Carburetor Page Page Disassembling the Carburetor 5 Carburetor Adiustments Inspection and 7 Automatic Choke Well 14 PART 2 BBD Series Carburetor Disassembling the Carburetor 1 16 Automatic Choke Well 23 Inspection and 17 Closed Crankcase Vent System 23 Carburetor Adiustmenis eee 19 Throttle Linkage 2 cee ee eee 23 PART 3 AFB Series Carburetor Disassembling the Corburetor 26 Automatic Choke Well 35 Inspection and 29 Closed Crankcase Vent System 36 Carburetor 4 32 Throttle Linkage 36 PART 4 Firepower 390 FUEL AND INDUCTION SYSTEM Intake 38 Inspection and 45 Throttle 41 Carburetor Adiustments 48 Disassembling the Carburetor AFB 43 Fuel Pump Opercotion 50 Fuel
31. GINE APPLICATION MAIN METERING Standard Lp ua eed One Step Two Steps Leoan MAIN JET POWER JET Zulu roD E Eee DNO eq s ees LOW SPEED JET Primory STEP UP WIRE DIAMETER Stondord 2 Stag ss scien Sean iU y uyawan STEP UP ROD 2 Stages usb uya i RENTEN ESOS 1 Size Lean oc erre ere ies 2 Sizes Lean SPECIFICATIONS Stromberg Dual Downdraft WWC3 244 WWC3 242 Manual Trans Auto Trans 361 361 VC 1 with Firebolt 265 1 nue 19e 19e Part No 388186 061 059 057 028 x 055 061 059 057 028 x 055 Ball amp Boll Dual Downdraft BBD 3685S 383 VC 2 with Carter 4 Barret Downdraft AFB 36145S 413 VC 1 Police Firepower 305 VC 2 Hi Perf 1 1 4 120 248 120 249 120 250 75 1598 031 x 026 with Firepower 360 TA 1 4 1 4 198 089 267 65 035 16 217 16 165 16 159 Carter 2 4 Barrel Downdraft AFB 3505S 413 VC 2 with Firepower 390 YA Ten 1 e 1 089 082 465 035 16 118 16 119 16 50 Carter 4 Barrel Downdraft AFB 3615S AFB 3644S 413 VC
32. ND ADJUST THE LENGTH OF THE TRANSMISSION ROD BY MEANS OF THE THREADED ADJUSTMENT AT THE UPPER END THE BALL SOCKET MUST LINE UP DIRECTLY WITH THE BALL END WITHOUT EXERTING ANY 9 FORWARD FORCE ON THE ROD THE BALL SOCKET MUST BE AT THE SAME HEIGHT AS THE BALL END WHEN CHECKING ROD LENGTH 10 LENGTHEN ROD BY ONE TURN OF THE ADJUSTMENT 5 ASSEMBLE BALL SOCKET TO BALL END WHEN THE CARBURETOR THROTTLE IS OPENED THE TRANSMISSION SHOULD BEGIN ITS TRAVEL AT THE SAME TIME WITH NO VERTICAL MOVEMENT OF THE LEVER OR VERTICAL MOVEMENT OF TH ROD IN THE LEVER ASSEMBLE REMAINDER OF THE LINKAGE PARTS IN PLACE WITH THE CABLE CLAMP NUT LOOSE ADJUST THE POSITION OF THE CABLE HOUSING FERRULE Q IN THE CLAMP SO THAT ALL SLACK I REMOVED FROM THE CABLE WITH THE CARBURETOR AT CURB IDLE TO REMOVE SLACK FROM THE CABLE MOVE THE FERRULE 9 IN THE CLAMP IN THE DIRECTION AWAY FROM THE CARBURETOR LEVER BACK OFF FERRULE 3 1 2 THIS PROVIDES 1 2 FREE PLAY BETWEEN THE REAR SURFACE OF THE ACCELERATOR BRKT AND THE FRONT EDGE OF ACCELERATOR SHAFT LEVER TIGHTEN CLAMP NUT 4 ROUTE CABLE SO THAT IT DOES NOT INTERFERE WITH THE TRANSMISSION ROD THROUGHOUT ITS FULL TRAVEL CONNECT CHOKE ROD 2 OR REMOVE BLOCKING FIXTURE 64 x 422 Fig 23 Throttle Linkage Adjustments Imperial JOW INIT Ze vl 14 38 FUEL AND INDUCTION SYSTEM PART 4 FIRE POWER 390 FUEL AND INDUCTION SYSTEM The Chrysler Fire Power 390 engine as s
33. NOT USE A SCREWDRIVER Turn the screws lightly against their seats with the fingers Back off one full turn for approximate adjustment Main Body 1 Invert the main body and place a new gasket in position and place the throttle body on the main body and align Install screws and tighten securely 2 Install the accelerator pump discharge check ball in the discharge passage and check the acceler ator pump system fuel inlet and discharge check balls as follows 3 Pour clean gasoline into the carburetor bowl approximately 1 2 inch deep Remove the pump plunger from the jar of gasoline flex the leather several times then slide down into the pump cylinder Raise the plunger and press lightly on the plunger shaft to expel all air from the pump passage 14 18 ACCELERATOR PUMP PLUNGER NO FUEL TO BE EMITTED PAST THE PUMP INTAKE CHECK BALL a NO FUEL TO BE EMITTED PAST THE DISCHARGE CHECK BALL 64 X 332 Fig 6 Testing the Accelerator Pump Intake and Discharge Check Balls 4 Using a small clean brass rod hold the dis charge check ball down firmly on its seat Again raise the plunger and press downward No fuel should be emitted from either the intake or discharge passage as shown in Figure 6 If any fuel does emit from either passage it indi cates the presence of dirt or a damaged check ball seat Check the passage again and repeat test If leakage is still evident install a new check ball The fuel
34. RAGM HOSE THROTTLE BODY ELEVATOR LEGS SET OF 4 64 x 328 Fig 1 Carburetor Assembly BBD 36855 14 16 BBD CARBURETOR PART 2 MODEL BBD 3685S CARBURETORS Dirt dust water and gummy deposits are some of the main causes for poor carburetor operation Proper cleaning however and installation of new parts where required will return the carburetor to its originally designed performance When overhauling the carburetor several items of importance should be observed to assure a good job All parts except the diaphragm assembly should be carefully cleaned in a suitable solvent and in spected for damage and wear Replace questionable parts with new ones Use air pressure only to clear the various orifices and passages SERVICE PROCEDURES 1 CARBURETOR DISASSEMBLY Fig 1 1 Insert three Tool T109 287S and one Tool T109 288S elevating legs through the carburetor throttle body stud holes These tools are used to protect the throttle valves from damage and to provide a suitable base for working 2 Remove the hairpin clip and disengage the fast idle connector rod from the throttle and fast idle levers 3 Remove the hairpin clip and disengage the accelerator pump rod from the throttle lever and the pump rocker arm 4 Remove the vacuum hose between the carburet or throttle body fitting and the vacuum diaphragm 5 Remove the clip from the choke operating link and disengage the link from the
35. RETOR 14 13 CHOKE VALVE IN WIDE OPEN POSITION FAST IDLE SPEED ADJUSTING SCREW ON LOWEST STEP OF CAM CURB IDLE SPEED FAST IDLE CAM ADJUSTING SCREW THROTTLE 64x240 Fig 24 Fast Idle Speed Adjustment On the Car 4 Repeat the idle mixture screw adjustment Fast Idle Speed Adjustment On the Engine To set the fast idle speed on the engine connect a tachometer to the vehicle then set the curb idle speed and proceed as follows 1 With the engine running and the transmission in the neutral position open the throftle slightly 2 Close the choke valve about 20 degrees then allow the throttle to close Return the choke valve to the open position 3 The fast idle speed adjusting screw should be contacting the lowest step on the fast idle cam as shown in Figure 24 4 With the engine warmed up to the normal operating temperature turn the fast idle speed ad justing screw in or out t secure 700 r p m Automatic Transmission or 600 r p m Manual Transmission Reposition the cam and throttle after each adjustment Measuring the Float Setting or Fuel Level On the Vehicle Remove the three sh rt air horn to main body at taching screws Then remove one long air horn to throttle body screw next to fuel bowl and assemble short screw through main body flange and thread into the throttle body Remove long screw from side away from fuel bowl and on opposite side and as semble short sc
36. RING FLOAT BAFFLE SHORT AIR HORN SCREWS Es 64x230 Fig 3 Removing the Air Horn spirits may damage the diaphragm material 8 Remove the remaining air horn attaching screws then lift air horn straight up and away from main body as shown in Figure 3 9 Disengage the accelerator pump plunger from the pump arm hook by tilting down and out from under hook as shown in Figure 4 Remove the com pression spring Place the accelerator pump plunger in a jar of clean gasoline or kerosene to prevent the leather from drying out 10 Remove the vacuum power piston from the air horn using an open end wrench and wood block as shown in Figure 5 Exert sufficient pressure on end of wrench to force piston out of its well in air horn This assembly is staked in the air horn and care should be used at removal Discard air horn gasket 11 Test the freeness of the choke mechanism in ACCELERATOR PUMP PLUNGER POWER PISTON STEM ACCELERATOR PUMP SPRING PUMP ARM HOOK 64x231 Fig 4 Removing the Accelerator Pump Plunger PISTON RETAINER STAKED IN THE AIR HORN 64x232 Fig 5 Removing the Vacuum Power Piston the air horn The choke shaft must float free to operate correctly If the choke shaft sticks in the bearings or appears to be gummed from deposits in the air horn a thorough cleaning will be required 2 MAIN BODY REMOVAL 1 Remove the venturi cluster attaching screws the venturi cluster and gas
37. RM CHOKE OPERATING LINK AIRHORN CHOKE VACUUM DIAPHRAGM FAST IDLE CONNECTOR ROD DIAPHRAGM VACUUM HOSE FAST IDLE CAM CURB IDLE SPEED ADJUSTING SCREW DISTRIBUTOR VACUUM ADVANCE TUBE FITTING THROTTLE LEVER IDLE MIXTURE ADJUSTING SCREWS FAST IDLE SPEED ADJUSTING SCREW CLOSED CRANKCASE VENT ELEVATING LEGS ACCELERATOR PUMP TUBE FITTING SET OF 4 CONNECTOR ROD 64x340 Fig 1 Carburetor Assembly AFB Series 14 26 AFB CARBURETOR PART 3 AFB CARBURETORS The AFB aluminum four barrel carburetor con tains many features some of which are the location for the step up rods and pistons The step up rods pistons and springs are accessible for service without removing the air horn or the carburetor from the engine The venturi assemblies primary and secondary are replaceable and contain many of the calibration points for both the high and low speed system One fuel bowl feeds both the primary and secondary nozzles on the right side while the other fuel bowl takes care of the primary and secondary nozzles on the left side This provides improved performance in cornering quick stops and acceleration All the major castings of the carburetor are alu minum with the throttle body cast integral with the main body This allows an overall height reduction in the carburetor The section containing the accel erator pump is termed the primary side of the car buretor The rear section is the secondary
38. TTLE BODY THROTTLE LEVER amp COSS s FAST iDLE ACCELERATOR PUMP ADJUSTING SCREW CONNECTOR ROD STEP UP PISTON COVER PLATE 2 ACCELERATOR PUMP CONNECTOR LINK CHOKE LEVER ACCELERATOR PUMP SHAFT r ACCELERATOR CHOKE CABLE PUMP ARM BRACKET ACCELERATOR PUMP CONNECTOR ROD SECONDARY THROTTLE OPERATING LEVERN 7 VACUUM ADVANCE FITTING OPENING CARBURETOR IDENTIFICATION x PRIMARY THROTTLE STAMPED ON BOSS SHAFT ARM OUTER 63x60 Fig 4 Carburetor Assembly 35055 sira 2 Turn air conditioning compressor OFF if so equipped before proceeding with following adjust ments 3 Remove each air cleaner 4 Disconnect each throttle rod at the bellerank on the intake manifold 5 Open the throttle valves of the left carburetor far enough to allow positioning of the fast idle cam to the fast idle index mark The right carburetor should remain at the curb idle position 6 Adjust fast idle screw until a fast idle speed of 1400 rpm is obtained 7 After the desired engine speed has been ob tained open the throttle slightly to allow the fast idle cam to return to the open choke or off fast idle position 8 Repeat steps 5 6 and 7 in setting right car buretor fast idle speed as it is very important at the completion of this step 8 that each carburetor has identical fast idle speeds There is no specification for engine rpm with both carbureto
39. VIDED IN THE ACCELERATOR SHAFT BRACKET AND LEVER ADJUST THE PEDAL ROD 6 LENGTH PROVIDE A PEDAL ANGLE OF 113 TO 115 INSTALL PEDAL ROD APPLY A THIN FILM OF M5 3608 LUBRICANT FO THE ACCELERATOR SHAFT UWHERE IT TURNSIN THE FIREWALL BRACKET ASSEMBLE CARBURETOR ROD PARTS amp UT DO NOT TIGHTEN ADJUSTMENT LOCK NUT 4 DISCONNECT CHOKE 2 AY CARBURETOR OR BLOCK CHOKE VALVE IN FULL OPEN POSITION THROTTLE SLIGHTLY TO RELEASE FAST IDLE CAM THEN RETURN CARBURETOR TO CURB IDLE WITH THE 3 16 DIAMETER BY 10 LONG ROD S IN PLACE IN THE ACCELERATOR SHAFT BRACKET AND LEVER ASSEMBLY TIGHTEN CARBU RETOR ROD ADJUSTMENT LOCK NUT CONNECT CHOKE ROD 2 OR REMOVE BLOCKING FIXTURE 113 TO 115 MOVE REAR PORTION OF CARBURETOR ROD ASSEMBLY 3 REARWARD UNTIL TRANSMISSION THROTTLE LEVER 7 STOP IS CONTACTED TIGHTEN CARBURETOR ROD ADJUSTMENT LOCK NUT CONNECT CHOKE ROD 2 0R REMOVE BLOCKING FIXTURE 63x367 Fig 18 Throttle Linkage Adjustments tUvl JOWINIT T ILLOWHI AFB CARBURETOR 14 25 UP PISTON COVER PLATE ACCELERATOR PUMP PLUNGER STEM CHOKE OPERATING LINK FUEL INLET FITTING CHOKE VACUUM DIAPHRAGM PLUNGER STEM SECONDARY THROTTLE OPERATING LEVER THROTTLE AND MAIN BODY PRIMARY THROTTLE SHAFT ARM OUTER PRIMARY THROTTLE E udi SHAFT DOG VACUUM DIAPHRAGM HOSE CHOKE VACUUM DIAPHRAGM BRACKET CHOKE LEVER CHOKE VALVE STEP UP PISTON COVER PLATE ACCELERATOR PUMP A
40. above test attempt to reseat needle or install a new check ball Discharge Check Needle 1 With the discharge check needle installed in sert a piece of drill rod down on the needle Lightly tap with a hammer on the end of the drill rod This will form a new seat for the needle 2 Remove and discard old needle and install a new one Retest as described above 3 If the service fix does not correct the condition a new carburetor will have to be installed 4 Install the accelerator pump discharge check needle jet housing and gasket Install attaching screws and tighten securely Press down on accelerator pump plunger a clear straight stream should flow from each jet If the streams are not identical if either one is diverted or restricted a new accelerator pump jet housing should be installed After test pour the gasoline from the bowl and re move plunger Assembling the Air Horn 1 Slide the fuel inlet screen into the fuel line inlet fitting and install in air horn Tighten securely Check to see if the leather on the pump plunger is hard cracked or worn If any sign of wear or deterioration is evident install a new plunger assem bly 2 Slide the compression spring over plunger shaft followed by the spring seat Now slide the pump assembly into the air horn Install S link to hold in position 3 Install new air horn to main body gasket then install the float needle valve seats Be sure each i
41. air cleaners 20 Refill the cooling system to required capacity Refer to specifications After the intake manifolds have been installed it is very important that the next procedure of setting the throttle linkage be done in order to obtain peak en gine performance 2 SETTING THE THROTTLE LINKAGE As mentioned previously setting the throttle link age is a very important step Various conditions af fecting car performance can be encountered such as loss of performance no wide open throttle response delayed shifting of the transmission no kickdown de layed up shifts and etc I Setting the throttle linkage is divided into three parts namely Positioning the accelerator shaft posi tioning the accelerator pedal setting the bellcrank and synchronizing each carburetor It is very im portant that the throttle linkage be set in this order Positioning the Accelerator Shaft To position the accelerator shaft if equipped with automatic transmission refer to Figure 3 then pro ceed as follows 1 Loosen the adjusting nuts A and B acceler ator shaft to transmission rod and accelerator shaft to throttle shaft lever rod 2 Insert a piece of 54 inch welding rod 10 inches long into the accelerator shaft bracket and through hole in lever 8 Now move the transmission throttle lever for ward until it stops Tighten the locknut A securely This positions the accelerator shaft Positioning the Accelera
42. air horn NOTE t is suggested that the float on the pump side be marked so that the floats can be re installed in their respective positions 2 Remove the two needle valves from their re spective seats after marking the one on the pump Side for identification Using a wide blade screw driver remove the needle valve seats Be sure each n edle valve is returned to its original seat at re assembly 3 Remove the hairpin clip that holds the accel erator pump connector link in the pump arm and plunger shaft Disengage link from pump arm and shaft Slide the accelerator pump pluhger and spring out of the air horn Remove the air horn to main body gasket and discard 4 Place the accelerator pump plunger in a jar of clean gasoline or kerosene to prevent the leather from drying out PUMP JET 63x50TA Fig 3 Removing Accelerator Pump Jet Housing 14 27 AFB CARBURETOR SPECIAL TOOL PRIMARY JET 2 SECONDARY JET 2 TM 63x502A Fig 4 Removing Main Metering Jets 5 Remove the fuel inlet fitting and filter screen from the air horn 6 Test the freeness of the choke mechanism in the air horn The choke shaft must float free to operate correctly If the choke shaft sticks in the bearings or appears to be gummed from deposits in the air horn a thorough cleaning will be required Main Body Disassembly 1 Remove the screws that attach the accelerator pump jet housing to the main bod
43. arburetor Fig 1 is a dual throat downdraft type with each throat having its own idle system main metering system and throttle valve The idle and main metering sys tem are supplemented by the float system the ac celerating system and the power system The carburetor incorporates an idle system vent operated from the throttle linkage a double venturi cluster which in addition to the small venturi also includes the discharge nozzles the main discharge tubes and the idle tubes in a single assembly Dirt dust water and gummy deposits are some of the main causes for improper carburetor operation Proper cleaning however and the installation of new parts where required will return the carburetor to its originally designed performance When overhauling the carburetor several items of importance should be observed to assure a good job 1 All parts except the diaphragm assembly should be carefully cleaned in a suitable solvent then inspected for damage or wear 2 Use air pressure only to clean the various orifices and channels 3 Replace questionable parts with NEW ones Always use a complete kit when overhauling the car buretor Using the code number stamped on the air horn adjacent to the fuel inlet refer to the parts catalog and order the correct repair kit for the car buretor being worked on SERVICE PROCEDURES 1 DISASSEMBLING THE CARBURETOR Figs 1 and 2 1 Install four elevating legs Tool T109 2
44. center hole of the pump arm Install clips to secure 4 CARBURETOR ADJUSTMENTS The following adjustments should be made on a reconditioned carburetor before installation on the vehicle Accelerator Pump Adjustment Measure the distance from the top of the air horn to the top of the plunger shaft using a T scale as shown in Figure 18 This distance should be 74 inch If an adjustment is necessary bend the pump rod at the lower angle using Tool T109 213 until the correct travel has been obtained Secondary Throttle Lever Adjustment 1 Invert the carburetor and slowly open the pri mary throttle valves until it is possible to measure py i Jens S doy i THROTTLE FULLY CLOSED Fig 18 Measuring the Accelerator Pump Travel BEND ROD AT THIS POINT surwaat X gt a SECONDARY THROTTLE VALVES JUST STARTING TO OPE A ie 63 620 N Q Fig 19 Measuring the Secondary Throttle Opening 296 inch between the lower edge of the primary valve and the bore opposite the idle port as shown in Figure 19 2 At this measurement the secondary throttle valves should just start to open The stop lugs on both the primary and secondary throttle levers should contact the bosses on the flange at the same time If an adjustment is necessary bend the secondary throttle operating rod at the angle using Tool T109 213 until correct adjustment has been obtained At wid
45. cture the location of the idle transfer ports and the spark advance control ports to the valves are carefully established for one par ticular assembly Fig 9 2 H a new shaft should be installed in an old worn throttle body it would be very unlikely that the original relationship of these ports to the valves would be obtained Changing the port relationship PORT IDLE TRANSFER PORTS SPARK ADVANCE Fig 9 Ports in Relation to the Throttle Valves WWCS CARBURETOR 14 8 THROTTLE THROTTLE VALVES BODY IDLE SPEED ADJUSTING a SCREW EE pel B SPRING espa Set E CRE eX THROTTLE LEVER AND SPRING IDLE MIXTURE SCREWS THROTTLE VALVE SCREWS Fig 10 Throttle Body Disassembled View would adversely affect normal car operation between the speeds of 15 and 30 miles per hour Jf it has been determined however that a new shaft or valves are to be installed adhere closely to the following instructions 3 Mark the valves to be sure each is replaced in the same bore from where removed if replacing throttle shaft only Fig 10 4 Remove the screws that hold the throttle valves to the shaft Slide the valves out of shaft and bore CAUTION These screws are staked on the op posite side and care should be used at removal so as not to break the screws in the shaft Remove the staking with a file 5 Slide the throttle shaft and lever out of the throttle body 6 Install
46. d fuel inlet needle 1 Invert the main body so that the weight of the floats only is forcing the needle against the seat Be sure hinge pin does not drop out of the float hinge Hold down with the fulcrum pin spring 2 Using Tool 73725 or a T scale measure the float level as shown in Figure 15 There should be 55 inch from the surface of the fuel bowl to the crown of the float at the center FLOAT GAUGE PRESSURE ON SPRING 60x346 Fig 15 Measuring the Float Setting 14 10 WWC3 CARBURETOR If an adjustment is necessary remove the needle valve and seat the fulcrum pin retainer spring the floats and fulcrum pin Bend the lip of the float lever either in or out until correct setting has been ob tained CAUTION Do not attempt to change the setting without removing the float as the synthetic rubber tip can be compressed sufficiently to cause a false setting which will affect correct level of fuel in the bowl NOTE H is important that the float lip is per pendicular to the needle or slanted not more than 10 degrees away from the needle when the float is set correctly Do not bend the float lip by forcing the float use Tool 73605 3 Install float needle and seat and tighten seat securely Slide the float baffle down into position and install the fulcrum pin spring Remeasure as de scribed in Step 2 above Air Horn Assembly Fig 16 1 Slide the choke shaft and lever into the air horn with th
47. diaphragm plunger and the choke lever Refer to Fig 1 6 Remove the vacuum diaphragm and bracket as sembly and place to one side to be cleaned as a special item A liquid cleaner other than mineral spirits may damage the diaphragm material 7 Remove the air horn retaining screws and lift air horn str ight up and away from the main body Discard the gasket MA en ej 8 Disengage the accelerator pump plunger from the accelerator pump arm by pushing up on the bot tom of the plunger and sliding the plunger shaft off the hook Slide the plunger out of the air horn and remove the compression spring and seat If the old plunger can be used again or if a new plunger is to be installed place the plunger in a jar of clean gasoline or kerosene to prevent the leather from drying out 9 Remove the fuel inlet needle valve seat and gasket from the main body 10 Lift out the float fulerum pin retainer and lift out the floats and fulcrum pin 11 Remove the step up piston and retaining screw and slide the step up piston and rods out of well as shown in Figure 2 Lift out the step up piston B4 STEP UP RODS STEP UP PISTON SPRING r RETAINING SCREW 60x102 Fig 2 Removing the Step up Piston MAIN METERING JETS 64 x 329 Fig 3 Removing the Main Metering Jet CCELERATOR PUMP DISCHARGE HOLES CCELERATOR PUMP ISCHARGE PASSAGE VENTURI CLUSTER 4S SCREWS 65 Fig 4 Removing the Ventur
48. e as described in the Fast Idle Speed Adjustment On the engine paragraph of this group however the Fast Idle Cam Position Adjust ment can be made on the bench as follows 1 With the fast idle speed adjusting screw con tacting the lowest step on the fast idle cam as shown in Figure 10 move the choke valve toward the closed position with light pressure Insert a 154 inch drill or gauge between the choke valve and the wall of the air horn DRILL OR GAUGE AT WIDEST OPENING NE LIGHT ENGER BEND STOP TO ADJUST CHOKE VALVE OPENING b SPE ON JE THE LOWEST STEP AND AGAINST THE FACE OF NEXT 3 E A SK ms 6x Fig 10 Fast Idle Cam Position Adjustment AT WIDEST CHOKE OPENING DIAPHRAGM PLUNGER STEM RETRACTED BY VACUUM A DISTRIBUTOR VACUUM M ADVANCE TUBE FITTING LIGHT CLOSING PRESSURE AGAINST CHOKE VALVE CHOKE DIAPHRAGM TUBE FITTING TO VACUUM SUPPLY 64 X 335 Fig 11 Measuring the Choke Vacuum Kick Setting 2 An adjustment will be necessary if a slight drag is not obtained as the drill or gauge is being removed 3 If an adjustment is necessary bend the stop on the choke shaft using Tool T109 22 until the correct valve opening has been obtained Refer to Fig 10 Vacuum Kick Adjustment This test can be made On or Off the vehicle To make the vacuum kick adjustment the vacuum diaphragm must be energized either a dis
49. e choke lever pointing down and away from the air horn Slide the choke valve down into the slot in the shaft 2 Hold the choke valve closed and instal new screws DO NOT TIGHTEN While holding the valve in the closed position tap gently with a screwdriver to center and locate the valve 3 Tighten attaching screws securely then stake by squeezing with pliers Reinstall the fast idle lever and secure with lockwasher and nut 4 Soak the accelerator pump plunger in a jar of clean gasoline Test the leather If the leather is hard cracked or worn install new pump plunger Be J FAST IDLE LEVER e eei BOWL VENT VALVE Fig 16 4Air Horn Disassembled View VACUUM P PISTON 2 z c 1 o C x P o gt sure and flex the leather several times before in stalling plunger in air horn 5 Slide the compression spring over plunger shaft then slide plunger over hook and into posi tion Fig 4 6 Install a new air horn gasket then install the vacuum power piston in air horn Lock the piston in position by prick punching on the retaining rim Compress the piston plunger to be sure no binding exists If the piston sticks or binds enough to hinder smooth operation install a new piston assembly 7 Install the air horn assembly on the main body guiding the pump plunger into its well Fig 2 Be sure the leather does not curl or fold back Install retaining screws and tighten secure
50. e disconnecting or connecting the fuel gauge wire 1 Drain the tank then disconnect the fuel line and the lead wire to the fuel gauge unit 2 Remove the screw that attaches the filler tube bracket to the trunk panel 3 Push the tube into the tank far enough for the tube bracket to clear the trunk panel Push the tube downward slightly so that the mounting bracket clears the opening in the panel Pull the tube out of the tank using a suitable tool 4 Loosen the nuts that hold the ends of the fuel tank tie down straps until the button heads can be disengaged from the floor pan brackets Disengage the studs from the brackets then lower the tank to the floor 5 Remove the tube seal and inspect H the seal is cracked or deteriorated install a new seal at reas sembly 6 Remove the gauge tank unit using spanner wrench Tool C 3582 Discard the gasket FILLER TUBE ASSY GROMMET TANK ASSEMBLY VIEW IN DIRECTION OF ARROW STUD 2 zc g4 NUT 2 Y STRAP 2 lt eil TANK ASSY Fig 4 Fuel Tank Mounting Imperial 60 x 98 14 54 FUEL TANK Installation f NOTE When installing a new tube seal be sure the diameter of the seal lip is placed in the tank open ing Do not use any lubricant on the seal at the tank contact surface NOTE Before installing the tank gauge unit in spect the condition of the filter on the end of the suc tion tube If the filter is corroded install a new f
51. e lip bending operation as required CAUTION When bending the float lip do not allow the lip to push against the needle as the rubber tip can be compressed sufficiently to cause a false setting which will affect correct level of fuel in the bowl After being compressed the rubber tip is very slow to recover its original shape It is very important that the float lip be perpen dicular to the needle or slanted not more than 10 degrees away from the needle when the float is set correctly 3 Reassemble the air horn 8 AUTOMATIC CHOKE Well Type To function properly it is important that all parts be clean and move freely Other than an occasional cleaning the automatic choke control requires no servicing It is very important however that the choke control unit works freely at the thermostatic coil spring housing and at the choke shaft Move the choke rod up and down to test for free movement of the coil housing on the pivot If the unit binds new unit should be installed NOTE The well type choke unit is serviced only as a complete unit Do not attempt to repair When installing the well type choke unit make cer tain that the coil housing does not contact the sides of the well Any contact at this point will affect choke operation Do not lubricate any of the choke parts or the control unit since this causes dirt to accumulate which would result in a binding condition of the choke mechanism Do not attempt t
52. e open throttle the primary throttle valves should be from 6 to 8 degrees past vertical The secondary throttle valves should be from 6 to 8 degrees before vertical position 3 With the primary and secondary valves tightly closed it should be possible to insert Tool T109 29 020 inch wire gauge between the positive closing shoes on the primary and secondary throttle levers as shown in Figure 20 If an adjustment is necessary bend the shoe on the primary throttle lever using Tool T109 22 until correct clearance has been obtained It is suggested that the carburetor bowls be filled with clean gasoline This will help prevent dirt that is trapped in the fuel system from being dislodged by the free flow of fuel as the carburetor is primed After all adjustments have been made reinstall the carburetor on the engine using a new gasket Tighten mounting stud nuts to 100 inch pounds FUEL AND INDUCTION SYSTEM 14 49 PRIMARY SHOE BEND TO ADJUST 63x621 Fig 20 Measuring the Clearance Between Closing Shoes Fast Idle Cam Indexing 1 Open the throttle valves to wide open position Close the choke valve tightly and then close the throttle valves This will position the fast idle cam to fast idle The index mark on the cam should split the center of the fast idle adjusting screw as shown in Figure 21 2 If an adjustment is necessary bend the fast idie connector rod at the angle using Tool T109 213 until the ind
53. e throttle body then install main body Install two short screws to secure 2 Install the main metering jets in the main body Tighten securely using Tool T109 173 Fig 8 3 Install the power by pass jet and new gasket Tighten securely using Tool 73598 Fig 7 4 Install the accelerator pump inlet check ball 94g inch in the pump well as shown in Figure 12 5 Install the accelerator pump discharge check ball inch in the discharge passage as shown in Figure 13 63x493 Fig 12 Installing Accelerator Pump Inlet Check Bali DISCHARGE PASSAGE 63x494A Fig 13 Installing the Discharge Check Ball 6 ACCELERATOR PUMP TEST 1 Pour clean gasoline into the carburetor bowl approximately 1 2 inch deep Remove the accelerator pump plunger from the jar of gasoline and slide down in its well Raise the plunger and press lightly on the plunger shaft to expel the air from the pump passage 2 Using a small clean brass rod hold the dis charge check ball firmly down on its seat Raise the pump plunger and press downward No fuel should be emitted from either intake or discharge passage as shown in Figure 14 3 If any fuel does emit from either the intake or discharge passages it indicates the presence of dirt or an imperfect seat The passages should be recleaned and then thoroughly blown out with com pressed air Examine the ball seat for signs of dam NO FUEL TO BE EMITTED PAST DISCH
54. e valve opening As an example if the choke valve opening is 010 inch in error the correction in the link length would be 010 inch 2 micrometer will be helpful in establishing the original length of the link as shown in Figure 12 before completing the adjustment 7 Install the choke operating link and retest the choke valve opening using a gauge or drill Refer to Fig 11 Reinstall the vacuum hose to the diaphragm and make the following test 8 With no vacuum applied to the diaphragm CHOKE VALVE WIDE OPEN CLEARANCE CHOKE VALVE CLOSED CLEARANCE CLOSED CHOKE Fig 13 Choke Operating Link Clearances 64x249 14 21 aj LIGHT CLOSING PRESSURE BBD CARBURETOR SONT aueh DRILL OR GAUGE THROTTLE LEVER AGAINST STOP THROTTLE IN WIDE OPEN POSITION 64x 337 Fig 14 Measuring the Choke Unfoader Setting some clearance should exist between the choke operating link and the choke lever slot in both the open and closed choke valve positions as shown in Figure 13 NOTE This clearance is necessary to allow the choke valve to close for starting as well as fully open position after the engine reaches the normal operating temperature If a clearance does not exist in both of these positions a retest of the operating link adjustment should be made NOTE Free movement of the choke valve between the closed and open positions is very necessary This free movement
55. ect drop setting has been obtained Bend the tab toward the needle seat to decrease the drop or away from the float to increase the drop After the floats have been checked and adjusted continue to assemble the carburetor as follows 2 Engage the accelerator pump arm with the plunger S link and install the pivot screw Tighten securely 3 Place the accelerator pump plunger spring in the pump well then lower the air horn carefully down on the main body Be sure the fuel baffles on the air horn slide down in front bowl side of the float chamber baffles or the air horn will not index correctly with the main body This can cause the floats to hang up Also be sure the leather on the pump plunger does not curl or wrinkle Accelerator pump operation will be affected if this precaution is not observed 4 Install the air horn attaching screws and tighten securely Install the choke cable bracket and attach ing screws Tighten securely The two long screws should be installed in the holes that are located at the air cleaner mounting surface The 1 inch screw at the front and the 115 inch at the rear 5 Slide the step up piston springs into the piston wells followed by the step up pistons and metering rods Install the cover plates and attaching screws while holding the step up pistons down in position Tighten screws securely Refer to Fig 5 6 Engage the accelerator pump rod with the throttle lever and in the
56. epeat steps 2 and 4 above if necessary After the proper idle speed has been obtained move the sliding link to the rear against the stop and tighten the nut securely 5 MEASURING THE FLOAT SETTING OR FUEL LEVEL On the Vehicle To measure the float setting with the carburetor mounted on the engine proceed as follows 1 Remove the hairpin clip and disengage the accelerator pump rod from the throttle lever and the pump rocker arm Disconnect the automatic choke rod by unsnapping clip 2 Remove the air horn attaching screws and lift the air horn straight up and away from the main body Remove the gasket 3 Set the float fulcrum pin by pressing a finger against the fulcrum pin retainer There should be enough fuel in the bowl to raise the floats so that the lip bears firmly against the needle Additional fuel may be admitted by slightly depressing the float If the fuel pressure in the line is insufficient to force the additional fuel into the bowl add the necessary fuel from a clean container WARNING Since the manifolds may be hot it is dangerous to spill fuel onto these surfaces Take the necessary precautions to avoid spillage 4 With only the pressure from the buoyant float holding the lip against the inlet needle check the float setting using Tool T109 282 or a T scale There should be inch from the surface of the bowl gasket removed to the crown of the floats at the center If an adjustment is necessar
57. ex mark on the cam indexes the fast idle adjusting screw THROTTLE HELD CLOSED eT Sie x 4 QT f FAST IDLE CAM FAST IDLE SPEED ADJUSTING SCREW 63x622 Fig 21 Fast Idle Cam Indexing 14 50 FUEL PUMP PART 5 FUEL PUMP TANK FUEL PUMP Fuel pump Model M 36728 is used on all Chrysler and Imperial engines The fuel pump is of the pressed steel type and cannot be disassembled for service If a pump malfunction occurs remove the old pump and install a new one 1 OPERATION FUEL PUMP The fuel pump Fig 1 is driven by an eccentric cam cast integral with the camshaft through the medium of a short push rod As the camshaft rotates the eccentric cam presses against the push rod forcing the pump rocker arm down This action lifts the pull rod and diaphragm upwards against the fuel pump main spring thus creating a vacuum in the valve housing which opens the inlet valves forcing fuel into the valve housing chamber On the return stroke the main spring forces the diaphragm to the down position which closes the inlet valves and expels the fuel in the valve housing chamber through the outlet valve to the fuel filter and the carburetor It is recommended that the fuel filter be replaced when performing an engine tuneup or at least every 16 000 miles DO NOT ATTEMPT TO CLEAN 2 TESTING THE FUEL PUMP On the Vehicle If the fuel pump fails to supply fuel properly to the carburetor the following tes
58. he four conventional systems used in this carbu retor are two float systems two low speed systems primary side only two high speed systems and the accelerator pump system f Dirt dust water and gummy deposits are some of the main causes for poor carburetor operation How ever proper cleaning and the installation of new parts where required will return the carburetor to its originally designed performance When overhauling the AFB carburetor several items of importance should be observed to assure a good job namely the carburetor should be carefully disassembled All parts thoroughly cleaned in a suit able solvent then inspected for damage or wear Only air pressure should be used to clear the various orifices and channels Questionable parts should be replaced with new ones When inspecting parts removed from the carburetor it is at times rather difficult to deter mine if they are satisfactory for further service It is recommended therefore that in such case that NEW parts be installed 3 CARBURETOR Disassembly 1 Place the carburetor on repair stand C 3400 or elevating legs 4 T109 287S These tools are used to protect the throttle valves from damage and to provide a suitable base for working 2 Remove the clip that holds the accelerator pump rod in the center hole in the pump arm and the hairpin clip that holds the rod in the throttle lever Remove the rod 3 Remove the hairpin clip that attaches the fa
59. he throttle shafts are excessively worn that a new carburetor be installed If the throttle valves however have become nicked burred or damaged new valves may be installed providing the following instructions are carefully followed SECONDARY VALVE BRASS PRIMARY VALVE ALUMINUM 53x946A Fig 8 Throitle Valve Identification NOTE The screws that attach the throttle valves are staked on the opposite side and care should be used in removal so as not to break the screws in the throttle shaft Remove the staked portion of the screws with a file Remove the screws that attach the primary throttle valves to the throttle shaft and slide valve or valves out of the bores Remove the screws that attach the secondary throt tle valves to the throttle shaft and slide valve or valves out of the bores The primary valves and secondary valves are not interchangeable and should be kept separate in order that each may be returned to its respective bore See Fig 8 3 CLEANING THE CARBURETOR PARTS The recommended solvent for gum deposits is de natured alcohol There are other commercial solvents however which may be used with satisfactory results The choke diaphragm can be damaged by solvents Avoid placing the diaphragm assembly in any liquid Clean the external surfaces with a clean cloth or soft wire brush Shake dirt or other foreign material from the stem side of the diaphragm Depressing the dia phragm s
60. he vacuum diaphragm fitting and re move any dirt or foreign material which could plug the passage Inspect the rubber hose for cracks be fore placing it on the correct fitting Refer to Fig 1 Do not connect the vacuum hose to the diaphragm fitting until after the vacuum kick adjustment has been made See Carburetor Adjustments 4 CARBURETOR ADJUSTMENTS It is very important that the following adjustments are made on a reconditioned carburetor and in the sequence listed Accelerator Pump 1 Back off the idle speed adjusting screw Open the choke valve so that the fast idle cam allows the throttle valves to be completely seated in the bores Be sure that the pump connector rod is installed in the center hole of the throttle lever 2 Close the throttle valves tightly Measure the 14 20 BBD CARBURETOR ad FROM TOP OF B PUMP SHAFT TO F AIR HORN SURFACE THROTTLE VALVES FULLY CLOSED BE SURE THE CURB IDLE SPEED ADJUSTING SCREW 64 X 333 IS BACKED OFF Fig 9 Measuring the Accelerator Pump Travel distance between the top of the air horn and the end of plunger shaft as shown in Figure 9 This meas urement should be 1 or 1 inch 3 To adjust the pump setting bend the pump con nector rod using Tool T109 213 at the lower angle of rod until the correct travel has been obtained Fast Idle Speed and Cam Position Adjustment The fast idle engine speed adjustment should be made on the engin
61. hown in Figure 1 is equipped with twin air cleaners twin AFB carburetors hand type chokes and two aluminum manifolds containing eight s eping passages four in each manifold all of which employs a new method of fuel induction SERVICE PROCEDURES 1 INTAKE MANIFOLDS Removal Fig 2 1 Drain the cooling system 2 Remove the carburetor air cleaners 3 Disconnect the fuel line between the fuel pump and the left hand carburetor 4 Disconnect the fuel line between the left and right hand carburetor Disconnect the choke control 5 Disconnect the vacuum line between the right hand carburetor and the distributor 6 Remove the high tension coil wire T Disconnect the throttle linkage at both carburet ors and the bell crank to the accelerator shaft 8 Loosen the clamps that attach the equalizer tube couplings to the manifolds and to the equalizer tube Slide either coupling inward on the tube far enough to clear the manifold tube opening Lift the equalizer tube couplings and clamps up and away from engine 9 Disconnect the power steering hoses if so equipped at the pump and secure against the fire wall Fig 1 Fire Power Manifold 10 Remove the air conditioning compressor and brackets if so equipped Refer to Air eee Section uet 11 Remove the eight attaching bolts that hold the left fender shield access plate to fender shield then slide plate out of the engine compartment aa
62. i Cluster spring Remove the step up piston gasket from the bottom of the well 12 Remove the main metering jets and gaskets as shown in Figure 3 13 Remove the venturi cluster screws then lift the venturi cluster and gaskets up and away from the main body as shown in Figure 4 Discard the gas kets Do not remove the idle orifice tubes or the main vent tubes from the cluster They can be cleaned in a solvent and dried with compressed air 14 Invert the carburetor and drop out the accel erator pump discharge check ball 15 Remove the idle mixture adjusting screws and springs from the throttle body 16 Remove the screws that attach the throttle body to the main body Separate the bodies and dis card the gasket The carburetor now has been disassembled into three sub assemblies the air horn main body and throttle body and the components of each disassem bled as far as necessary for cleaning and inspection It is usually not advisable to remove the throttle shaft or valves from the throttle body unless wear or damage necessitates the installation of new parts 2 CLEANING CARBURETOR The recommended solvent for gum deposits is de natured alcohol which is easily obtainable There are other commercial solvents however which may be used with satisfactory results The choke diaphragm can be damaged by solvents Avoid placing the diaphragm assembly in ANY liquid Clean the external surfaces with a clean cloth or soft
63. ilter unit 1 Position the fuel tank gauge unit in the tank using a new gasket Using Tool C 3582 tighten the unit securely 2 Install a new filler tube seal in the tank opening as described above Lightly coat the inner side of the seal with lubriplate 3 Slide the tank up into position against the locator embossments on the floor pan Install the but ton head studs in the slots in the floor pan brackets Snug down the nuts but do not tighten 4 Check and be sure the fuel tank is in the cor rect position then tighten the nuts securely 5 Connect the fuel line to the tank fitting and the lead wire to the gauge unit 6 Insert the filler tube through the trunk panel and into the seal Push the tube into the tank far enough for the tube mounting bracket to clear the trunk panel opening Slightly pull the tube out of the tank until the bracket aligns with the mounting screw hole Install the screw and tighten securely 7 Refill the tank and inspect for leaks 3 FUEL TANK Town and Country Fig 2 Removal CAUTION Bae sure the Ignition Switch is turned OFF before disconnecting or connecting the gauge wire 1 Drain the tank and disconnect the fuel line and the lead to the gauge unit under the rear fender behind the wheel house 2 Remove the screws that attach the stone shield to the lower edge of the wheel house at the rear Remove the shield 3 Remove the button plug at the rear
64. in stallation 7 Remove the two idle mixture adjusting screws and springs from the throttle body portion of the main casting The carburetor now has been disassembled into two units the air horn and main and throttle body casting The component parts of each have been dis assembled as far as necessary for cleaning and in spection It is usually not advisable to remove the throttle shafts or valves unless wear or damage necessitates SECONDARY VENTUR PUMP SIDE gt SECONDARY VENTURI CHOKE SIDE NOZZLE BLEEDER TUBE PRIMARY VENTURI IDLE TUBE lt DO NOT REMOVE TUBES FROM VENTURI 63x504A Fig 6 Removing Secondary Venturi IDLE DISCHARGE PORTS PRIMARY THROTTLE VALVES IDLE TRANSFER PORTS 63x505A Fig 7 Ports in Relation to Throttle Valves the installation of new parts During the manufacture of the carburetor the location of the idle transfer ports and the idle discharge ports to the valve is carefully established for one particular assembly as shown in Figure 7 The valves are milled to E the proper port relation Xf new throttle shafts should be installed in an old worn body it would be very unlikely that the original relationship of these ports to the valves would be obtained A very slight change in the port relationship to the valves would adversely affect nor mal carburetor operation between the speeds of 15 and 30 miles per hour It is recommended that if t
65. in Figure 18 3 Close the throttle valves until the fast idle speed adjusting screw contacts the fast idle cam 4 Adjust the fast idle connector rod using Tool 1109 213 by bending at the angle until the fast idle speed adjusting screw lightly contacts the middle step on the fast idle cam but slides onto the bottom step of the cam The fast idle speed xa screw must DRILL OR GAUGE LIGHT CLOSING PRESSURE 4 AGAINST CHOKE VALVE 4 BEND FAST IDLE CONNECTOR ROD AT THIS ANGLE FAST IDLE ADJUSTING SCREW ON LOWEST STEP OF CAM AND RIDING AGAINST SHOULDER OF MIDDLE STEP FAST IDLE CAM 64x346 Fig 13 Fast Idle Cam Position Adjustment GAUGE OR DRILL LIGHT CLOSING PRESSURE AGAINST VALVE CHOKE OPERATING LINK TO VACUUM SOURCE SLOT DIAPHRAGM STEM OF VACUUM ON DIAPHRAGM VACUUM CHOKE REQUIRED TUBE FITTING 64x348 Fig 14 Measuring the Choke Vacuum Kick Setting touch or ride against the shoulder of the middle step on the cam This special procedure is required because the fast idle speed cam is spring loaded to follow the choke valve Vacuum Kick Adjustment This test can be made ON or Off the vehicle To make the vacuum kick adjustment the vacuum diaphragm must be energized either a distributor testing machine with a vacuum source or vacuum supplied by another vehicle To make this adjust ment proceed as follows 1 With the engine Not runni
66. ine warmed up to the normal operating temperature turn the fast idle adjusting screw in or out to secure 700 rpm Repesition the cam and throttle after each adjustment 6 AUTOMATIC CHOKE WELI TYPE To function properly it is importamt that all parts be clean and move freely Other than an occasional cleaning the choke requires no servicing It is very important however that the choke control unit work freely in the well and at the choke shaft Move the choke rod up and down to check for free movement on the pivot If the unit binds a new BBD CARBURETOR 14 23 CARBURETOR ASSEMBLY SDN HOSE Sou A 24028 t I d x BN 61x163 Fig 17 Closed Crankcase Vent System choke unit should be installed THE WELL TYPE CHOKE UNIT is serviced as an assembly Do not attempt to repair or change the index setting When installing the well type choke unit be cer tain that the coil housing does not contact the sides of the well in the intake manifold Any contact at this point will affect choke operation Do not lubricate any parts of the choke or the con trol unit This causes an accumulation of dirt which will result in binding of the choke mechanism 9 CLOSED CRANKCASE VENT SYSTEM The closed crankcase ventilator valve is located in the crankcase vent tube cap and is connected to the carburetor throttle body with a rubber tube See Fig 17 The function of the valve is to regulate the flow of unburned hydrocarbons fro
67. ing Chrysler Except Town and Country 14 52 FUEL TANK The fuel tank on all models except the Town and Country has a 23 gallon capacity The Town and Country capacity is 21 gallons The filer tube on the conventional models is accessible through the center of the deck opening lower panel while the Town and Country fills at the left rear upper quarter panel between the quarter post and the fin The fuel tank is fitted with a gauge unit including the suction pipe as shown in Figure 2 The filter on the end of the suction pipe is replaceable unit and prevents the entry of water and dirt When installing a tank unit be sure the filter is pushed on the end of the tube until seated 1 REMOVING THE FUEL TANK Except Town and Country and Imperial CAUTION Be sure the ignition switch is turned off before disconnecting or connecting the gauge wire Removal 1 Drain the tank into a safety can then discon nect the fuel line and the wire lead to the gauge unit 2 Disconnect the vent tube at the nose connection at the leading edge of the tank CAP ASSY a SCREW 3 FILLER TUBE RING BOLT ASSY TANK ASSY 3 Remove the nuts that hold the ends of the fuel tank hold down straps to the frame Lower the front end of the tank far enough to disengage the filler tube from the rear panel and slide out from under the vehicle 4 Remove the tank gauge unit using spanner wrench Tool C 3582 Fig 3 Check the
68. ir pressure It is further advisable to rinse all parts in clean kerosene or gasoline to be certain no trace of moisture remains Never clean jets with a wire drill or other mechanical means because the orifices may become enlarged making the mixture too rich for proper performance Inspection and Reassembly Throttle Body It is usually not advisable to remove the throttie shafts or valves unless the wear or damage is suffi cient to affect idle or operation of the carburetor If SPARK ADVANCE CONTROL PORT ae amp PRIMARY IDLE TRANSFER THROTTLE VALVE PORTS SECONDARY 63x616 Fig 12 Ports in Relation to Throttle Valves 14 46 FUEL AND INDUCTION SYSTEM such is the case install a new main and throttle body assembly However damaged valves can be replaced providing the instructions for installation are followed closely During manufacture the location of the idle trans fer port and the spark advance control ports to the valves is carefully established for one particular as sembly See Fig 12 Changing the port relationship would affect vehicle operation between the speeds of 15 and 30 miles per hour If it is necessary to install new valves proceed as follows 1 Remove the screws that hold the throttle valve or valves to be replaced to the throttle shaft then slide valve or valves out of the bore CAUTION These screws are staked on the op posite side and care should be used so as not to break
69. ket as shown in Figure 6 Discard the gasket 2 Remove the float fulcrum pin spring the fuel inlet needle valve seat and gasket 3 Slide the float baffle up and out of its grooves and remove the float and fulcrum pin 4 Invert the carburetor main body and drop out the discharge check ball from the discharge passage Fig 6 and the accelerator pump inlet check ball from the pump well 5 Using Tool 73598 remove the power by pass jet and gaskets as shown in Figure 7 FLOAT BAFFLE ua FULCRUM PIN t i 63x488 4 Fig 6 Removing the Venturi Cluster POWER BY PASS JET 63x489 Fig 7 Removing the Power By Pass Jet 6 Using Tool T109 173 remove the two main metering jets as shown in Figure 8 7 Remove the two air horn screws used to hold the main and throttle bodies together Separate the throttle and main bodies 3 THROTTLE BODY REMOVAL 1 Unscrew and remove the two idle mixture ad justing screws and springs from the throttle body 2 The carburetor now has been disassembled into three units namely the air horn main body and throttle body and the component parts of each dis assembled as far as necessary for cleaning and inspection NOTE It is usually not advisable to remove the throttle shaft or valves unless wear or damage ne cessitates installation of new parts SPECIAL _JSMAIN METERING JET 7 amp BY PASS JET PS CO QET GASKET 63x490 Fig 8 Removing
70. l T109 22 until correct clearance has been obtained After bending arm recheck the float align ment Float Drop Setting 1 Holding the air horn in an upright position measure the distance from the top of the floats outer end to the air horn gasket as shown in Figure 11 This measurement should be 34 inch If an adjustment is necessary bend the stop tabs on the float levers until the correct drop setting has been obtained Bend the tab towards the needle seat to lessen the drop or away from the seat to increase the drop 2 After the floats have been inspected and ad justed continue to assemble the carburetor as fol lows 3 Place the accelerator pump plunger lower spring in the pump cylinder then lower the air horn carefully down on the main body CAUTION Be sure the fuel baffles on the air horn slide down in front bowl side of the float chamber baffles or the air horn will not index cor rectly with the main body and can cause the floats to hang up Be sure the leather on the plunger does not curl or wrinkle Accelerator pump operation will be affected if this precaution is not observed 4 Install the 10 air horn attaching screws and tighten securely The two long screws should be in stalled in the holes that are located at the air cleaner mounting surface The 1 inch screw at the front and the 115 inch at the rear AFB CARBURETOR 14 31 2 STAGE STEP UP STEP UP PISTON PISTON SPRING oan P1 c
71. l from the fully closed to the fully open throttle 2 This travel should be 74 inch as shown 3 If an adjustment is necessary bend the pump rod at the point shown using Tool T109 213 until correct travel has been obtained Bowl Vent Valve Setting Fig 23 This setting is made after the pump travel setting 1 With the throttle valves at curb idle there should be 4 inch clearance between the bowl vent valve and the air horn when measured at the center of the vent valve and the seat with a gauge or drill shank 2 I an adjustment is necessary bend the bowl vent lever using Tool T109 214 until the correct opening has been obtained Idle Speed Adjustment For the best results it is recommended that a tach ometer be used in this adjustment 1 Turn the idle speed screw in or out to obtain 500 rpm On vehicles with air conditioning set the idle speed at 500 rpm with air conditioning ON Be sure the choke valve is fully open and that the fast idle adjusting screw is not contacting the fast idle cam engine off fast idle 2 Turn each idle mixture screw in or out until smooth idle is obtained 3 Readjust to 500 rpm with the idle speed screw CHOKE VALVE WIDE OPEN GAUGE INSERTED BETWEEN VALVE AND SEAT THROTTLE CLOSED THROTTLE VALVES AT CURB IDLE POSITION BOWL VENT LEVER BEND AS REQUIRED AT THIS POINT 64x239 Fig 23 Measuring Bowl Vent Valve Opening WWC3 CARBU
72. lpful in establishing the original length of the link as shown in Figure 15 before completing the adjustment 7 Install the choke operating link and retest the choke valve opening using a drill or gauge Refer to Fig 14 Reinstall the vacuum hose to the diaphragm and make the following test 8 With no vacuum applied to the diaphragm some clearance should exist between the choke operating link and the choke lever slot in both the open and closed choke valve positions as shown in Figure 16 CHOKE LEVER CHOKE VALVE OPEN CLEARANCE CHOKE LEVER CHOKE VALVE CLOSED CLEARANCE Fig 16 Choke Operating Link Clearances AFB CARBURETOR 14 33 LIGHT CLOSING PRESSURE AGAINST CHOKE VALVE BEND UNLOADER LIP UNLOADER SHOULD CONTACT FAST IDLE LINK LEVER ARM THROTTLE iN WIDE OPEN POSITION 64x351 Fig 17 Testing Choke Unloader Wide Open Kick NOTE This clearance is necessary to allow the choke valve to close for starting as well as fully open after the engine reaches the normal operating temper ature If a clearance does not exist in both of these posi tions a retest of the operating link adjustment should be made NOTE Free movement of the choke valve between the closed and open positions is very necessary This free movement should also exist between the kick and the open choke valve positions with the engine running If binding does exist the choke operating link has been im
73. ly NOTE The choke valve must be held partially closed while installing the air horn 8 Remove the two short screws holding the main body and throttle body together Fig 2 and install in air horn Reinstall the two long screws and tighten securely 9 Install the fast idle rod and secure with the hairpin clip 10 Install the pump rod and secure with hairpin clip Be sure rod is in the center slot of arm refer to Figure 1 Work the accelerator pump plunger several times to be sure it operates smoothly Installing the Vacuum Diaphragm 1 Install the diaphragm assembly on the air horn and tighten the attaching screws securely 2 Install the choke operating link in position be tween the diaphragm stem plunger and the choke lever Install the clip to secure 3 Inspect the vacuum diaphragm fitting and re move any dirt or foreign material which could plug the passage Inspect the rubber vacuum hose for cracks before placing it on the correct vacuum fit ting Refer to Fig 1 Do not connect the vacuum hose to the diaphragm fit ng until after the vacuum kick adjustment has been made See Carburetor Adjustments 7 CARBURETOR ADJUSTMENTS It is very important that the following adjustments be made on a reconditioned carburetor and in the sequence listed a Fast Idle Speed and Cam Position Setting b Vacuum Kick Adjustment c Unloader Adjustment Wide Open Kick d Accelerator Pump Travel e
74. m or if equipped with air conditioning 500 rpm with the compressor ON The idle bypass air screw is located at the front of each carburetor body flange between the two idle mixture screws Adjust the idle mixture screws on each carburetor for maximum rpm Repeat on each carburetor Before attaching the rod at each carburetor check the transmission to throttle linkage adjustments so that the idle position is not disturbed NOTE Accurate carburetor synchronization or balance is exteremely important and when performed should be rechecked and rebalanced in the outside ambient temperature after a five mile or more road test This readjustment will prevent rough engine idle performance and possible engine stalling when the vehicle is returned to the owner Fast Idle Adjustment On Vehicle When making fast idle adjustment on the vehicle each AFB carburetor should be adjusted individually 1 The engine should be at normal operating tem perature and have a curb idle speed of 700 rpm or if equipped with air conditioning 500 rpm with the compressor ON 14 42 FUEL AND INDUCTION SYSTEM CHOKE VALVE FUEL INLET FITTING STEP UP PISTON COVER PLATE 2 CHOKE CABLE LAMP AIR HORN IDLE MIXTURE ADJUSTING SCREWS FAST IDLE ROD FAST IDLE CAM CARBURETOR IDENTIFICATION STAMPED ON BOSS gt IDLE BY PASS a b e i ELEVATING LEGS SET OF 4 ADJUSTING SCREW lt MAIN AND THRO
75. m the crankcase and return them to the intake manifold From here they enter the combustion chamber and then exit with the exhaust system as completely burned exhaust products For servicing procedures of this system refer to Engine Group 9 10 THROTTLE LINKAGE To adjust the throttle linkage refer to Figure 18 for the complete instructions WITH AUTOMATIC TRANSMISSION ASSEMBLE ACCELERATOR SHAFT ASSEMBLY AND PEDAL ASSEMBLY TO BODY WITH A 3 16 DIAMETER ROD S APPROXIMATEL Y T0 LONG IN THE HOL ES PROVIDED IN THE ACCELERATOR SHAFT BRACKET AND LEVER ADJUST THE PEDAL ROD 6 LENGTH TO PROVIDE PEDAL ANGLE OF 1139 TO 115 INSTALL PEDAL R D 6 APPLY A THIN FILM OF MS 3608 LUBRICANT TO THE ACCELERATOR SHAFT 1 WHERE IT TURNS IN THE FIREWALL BRACKET ASSEMBLE CARBURETOR ROD PARTS BUT DO NOT TIGHTEN ADJUSTMENT LOCK NUT DISCONNECT CHOKE 2 AT CARBURETOR OR BLOCK CHOKE VALVE IN FULL OPEN POSITION OPEN THROTTLE SLIGHTLY TO RELEASE FAST IDLE CAN THEN RETURN CARBURETOR TO CURB IDLE WITH THE TRANSMISSION ROD ASSEMBLY AND TRANSMISSION THROTTLE LEVER IN PLACE MOVE THE TRANSMISSION THROTTLE LEVER 7 FOR WARD AGAINST THE STOP AND TIGHTEN TRANSMISSION ROD ADJUSTMENT LOCK NUT 8 REMOVE 3 16 DIAMETER ROD S FROK ACCELERATOR SHAFT BRACKET WITH MANUAL TRANSMISSION ASSEMBLE ACCELERATOR SHAFT ASSEMBLY AND PEDAL ASSEMBLY TO BODY WITH 3 16 DIAMETER ROD 5 JAPPROXIMATELY 10 LONG IM THE HOLES PRO
76. measure 2 inch between the lower edge of the primary valve and the bore opposite idle port as shown in Figure 19 At this measurement the secondary valves should just start to open 3 If an adjustment is necessary bend the sec ondary throttle operating rod at the angle using Tool T109 213 until correct adjustment has been obtained 4 With the primary and secondary throttle valves in the tightly closed position it should be possible to insert Tool T109 29 020 inch wire gauge between the positive closing shoes on the secondary throttle levers as shown in Figure 20 5 If an adjustment is necessary bend the shoe on the secondary throttle lever using Tool T109 22 until correct clearance has been obtained Secondary Throttle Lock out Adjustment 1 Open the throttle valves slightly then manu ally open and close the choke valve The tang on the secondary throttle lever should freely engage in the notch of the lock out dog Refer to Fig 19 2 If an adjustment is necessary bend the tang on the secondary throttle lever until engagement has been made Use Tool T109 22 for this operation 3 After adjustments have been made reinstall carburetor on engine using a new gasket 4 It is suggested that the carburetor bowl be filled with clean gasoline This will help prevent dirt that is trapped in the fuel system from being dis SECONDARY THROTTLE VALVES SHOULD JUST START TO OPEN BEND ROD AT THIS ANGLE
77. nel Attach with the strap and bolt Do not tighten 5 Place a new gasket over the filler tube and down against the flange Insert the filler tube down into neck of tank Drive the tube into O ring until the dimples in the tube contact the seal retainer Be sure the anchor tab on the tube is aligned with a screw hole Install the screws and tighten securely 6 Tighten the fuel tank hold down strap bolt securely 7 Install the stone shield Connect fuel line and lead to gauge unit Reinstall the button plugs Refill the tank and check for leaks For testing the fuel gauge refer to the Electrical Group 8 Gauges Condition Poor Idling Poor acceleration Carburetor floods or leaks a b d e f a b e d e f g h a b PART 6 DIAGNOSIS FUEL SYSTEM 14 55 SERVICE DIAGNOSIS Possible Cause Idle air bleed carbonized or of incorrect size Idle discharged holes plugged or gummed Throttle body carbonized or worn throttle shaft Damaged or worn idle mixture needle Low grade fuel or incorrect float level Loose main body to throttle body screws Accelerator pump by pass seat corroded or bad Accelerator pump piston or plunger leather too hard worn or loose on stem Faulty accelerator pump discharge ball Faulty accelerator pump inlet check ball Incorrect fuel or float level Worn or corroded needle val
78. ng open the throttle valves far enough to allow the choke valve to be moved to the closed position 2 Disconnect the vacuum hose from the dia phragm and connect the hose from the vacuum sup ply as shown in Figure 14 A minimum of 10 inches of mercury HG will be required 3 Insert inch drill or gauge between the choke valve and the wall of the air horn Refer to Fig 14 Apply a slight closing pressure to the choke shaft to hold the drill or gauge in position 4 An adjustment will be necessary if a slight drag is not obtained as the drill or gauge is being removed The adjustment of this opening will require the removal of the choke operating link CAUTION DAMAGE TO THE DIAPHRAGM AND THE CHOKE LEVER SLOT CAN RESULT IF THE LINK IS NOT REMOVED FOR THE BENDING OP ERATION 5 Remove the clip and disengage the choke opera ting link from the choke lever then disengage the link from the diaphragm stem The best bending CHOKE OPERATING LINK 64x349 Fig 15 Choke Operating Link Measurement results will be obtained by using a vise and a pair of pliers 6 Bend the choke operating link to the correct choke valve opening CAUTION A correction in the length of the link of 015 inch will result in a change of 010 inch in the choke valve opening As an example if the choke valve opening is 010 inch in error the correction in the link length would be 015 A 2 micrometer will be he
79. o change the calibration setting This is pre determined and should it be changed im proper choke action would result The choke control unit is accurately adjusted when originally assembled Under normal service operation it is recommended not to change the setting or to dis assemble the components for servicing If however the setting has been disturbed reset as follows Loosen locknut and turn part with screwdriver until index mark on disc coincides with the first mark to the right of center mark on the bracket Hold in this position with serewdriver while tightening nut NOTE After adjustment is made and the choke unit installed on the engine lift the cover disc and check to see that the rod has clearance when the choke is opened and closed The rod should have clearance at hole in cover plate Should it become necessary to adjust the throttle linkage refer to Figure 18 for the complete instruc tions BBD CARBURETOR 14 15 BOWL VENT UNLOADER TANG FAST IDLE D EAST LE SPEED ADJUSTING SCREW ACCELERATOR PUMP ROD VENT HOLE THROTTLE LEVER CURB IDLE SPEED ADJUSTING SCREW CHOKE VALVE AIR HORN CHOKE LEVER CHOKE OPERATING LINK CARBURETOR IDENTIFICATION FAST IDLE gt To SPEED ADJUSTING SCREW FAST IDLE MAIN BODY CONNECTOR ROD DISTRIBUTOR VACUUM CURB IDLE ADVANCE TUBE FITTING SPEED ADJUSTING SCREW CHOKE VACUUM DIAPHRAGM CLOSED CRANKCASE E FITTING VACUUM VENT TUBE DIAPH
80. of wheel house front of gauge unit 4 Remove the bolt and washer that attaches the tank hold down strap to the lower support 5 Remove the filler cap and the filler tube sleeve attaching screws Using a suitable tool or Tool C 3584 pull out the filler tube Slide the sleeve out of the body opening Remove the gasket from sleeve and O ring from the filler tube 6 Slide the tank down and out from under the quarter panel Reach up under the quarter panel and disengage the hold down strap from the bracket If Strap is to be replaced refer to Figure 2 7 Loosen the tank gauge unit using a spanner wrench Tool C 3582 Slide the unit up and out of the tank Check the condition of the rubber ring If cracked or deteriorated install a new ring at reassembly Installation Before installing the tank gauge unit check the condition of the filter on the end of suction tube If the filter is corroded install a new filter 1 Position the fuel tank gauge unit in tank using a new gasket Tighten securely using Tool C 3582 2 Slide the hold down strap under this quarter panel inserting the end of strap into slot Allow the strap to hang 3 Install a new ring in the neck of the tank 4 Slide the tank up under the quarter panel with the gauge unit facing front of the vehicle Push the tank up into position Make sure the filler neck is aligned with the opening in top of the quarter pa
81. ontinued Condition Possible Cause Correction f Air cleaner gasket interferes with choke valve or linkage Low Engine Output a Engine lubricating oil of 10 F or lower incorrect viscosity b Valve Lash incorrect e Choke thermostat ad justrnent incorrect rich ENGINE RUNS LEAN FIRST HALF MILE Choke Lean a Cheek items under Poor Starting b Diaphragm adjustment lean ENGINE RUNS LEAN AFTER HALF MILE Engine Heat a Heat valve stuck open Insufficient b Heat valve thermostat distorted c Heat valve failed within exhaust See engine section for proper diagnosis d Water temperature sub normal Carburetor Mixtures a Air leak bypassing the Lean carburetor b Carburetor has economy metering system f Reinstall gasket properly a Recommend 5W 20 b Readjust c Adjust to correct setting a See Choke Valve Fails to Close b Readjust to specification a Free with solvent b Replace thermostat c Replace heat valve d Test the thermostat a Repair b Inform customer ENGINE RUNS EXCESSIVELY RICH AFTER COLD START Choke System Rich a Choke thermostat ad justment richer than specified b Choke thermostat dis torted rich by overheating c Choke vacuum dia phragm inoperative or misadjusted d Choke Vacuum passage blocked or leaking Carburetor Rich a Incorrect gasket or gasket installation between carburetor
82. ot contacting the fast idle cam 2 Turn each idle mixture screw to obtain the highest rpm While making the adjustment carefully watch the tachometer and notice that the speed can be decreased by turning the screws in either direction from the setting that gave the highest rpm reading 3 Readjust to 500 rpm with the idle speed screw Air conditioning ON 4 Turn each idle mixture adjusting screw in the clockwise direction leaner until there is a slight drop in rpm Turn each screw out counter clockwise richer just enough to regain the lost rpm This procedure will assure that the idle has been set to the leanest possible mixture for smooth idle This setting is very important NOTE Since the correct speed was originally set using the speed screw the speed obtained after finding the leanest smooth idle setting will probably be too fast 5 Readjust the speed screw to obtain correct idle speed Repeat steps 2 and 4 above if necessary After the proper idle speed has been obtained move the sliding link to the rear against the stop and tighten the nut securely Fast Idle Speed Adjustment On the Engine To set the fast idle speed on the engine connect a tachometer to the vehicle then set the curb idle speed and proceed as follows 1 With the engine running and the transmission in the neutral position open the throttle slightly 2 Close the choke valve about 20 degrees then AFB CARBURETOR 14 35 CAR
83. ould be at least 10 of vacuum at 500 rpm with the fuel line disconnected at the carburetor Volume Test The fuel pump should supply 1 quart of fuel in 1 minute or less at 500 rpm Inlet Valve Test To test the inlet valve connect a vacuum gauge on the inlet fitting while the line is disconnected FUEL TANK 14 51 1 Start the engine or turn over with the starting motor 2 There should be a noticeable vacuum present not alternated by blowback 3 If blowback is present the inlet valves are not seating properly and should be cleaned or a new valve body installed If the fuel pump does not perform to the above test requirements the fuel pump should be removed from the vehicle and reconditioned as follows FUEL TANK The fuel tank on all models except the Town and Country Modelg is located at the rear of the body under the trunk compartment floor as shown in Figure 1 In the Town Country models the fuel tank is mounted in the left rear quarter panel beyond the wheel house shown in Figure2 TANK ASSY INSULATOR If the vehicle is to be stored for any appreciable length of time the gasoline should be drained from the entire system in order to prevent gum formation If the vehicle has been undercoated be sure the fuel tank vent tube under kickup in floor pan is open If this is not done a collapsed fuel tank will result FILLER TUBE ASSY STRAP 60 x 96A Fig 1 Fuel Tank Mount
84. phragm stem The best bending results will be obtained by using a vise and a pair of pliers 6 Bend the choke operating link at the angle to provide the correct choke valve opening CAUTION A correction in the length of the link of 010 inch will result in a change of 010 inch in the choke valve opening As an example if the choke valve opening is 010 inch in error the correction in the link length would be 010 inch A 2 micrometer will be helpful in establishing the original length of the link as shown in Figure 19 before completing the adjustment 7 Install the choke operating link and remeasure the choke valve opening using a gauge or drill Refer to Fig 18 14 12 WWC3 CARBURETOR CHOKE OPERATING LINK Fig 19 Choke Operating Link Measurements Reinstall the vacuum hose to the diaphragm and make the following test 8 With no vacuum applied to the diaphragm some clearance should exist between the choke operating link and the choke lever slot in both the open and closed choke valve positions as shown in Figure 20 This clearance is necessary to allow the choke valve to close for starting as well as fully open after the engine reaches the normal operating temperature If a clearance does not exist in both of these posi tions a retest of the operating link adjustment should be made FREE movement of the choke valve between the closed and open posit ons is very necessary This free movement
85. plying pressure on the end of the float shell with the fingers while supporting the float lever with the thumb To avoid damage to the float apply only enough pressure to bend the float lever 3 After aligning the floats remove as much clearance as possible between the arms of the float lever and the lugs on the air horn To do this bend GASKET IN PLACE 64x344 Fig 16 Measuring the Float Height 14 48 FUEL AND INDUCTION SYSTEM GASKET IN PLACE BEND STOP TABS EACH FLOAT 64x345 Fig 17 Measuring the Float Drop the float lever The arms of the float lever should be parallel as possible to the inner surfaces of the lugs or the casting Float Level Setting 1 With the air horn inverted the air horn gasket in place and the float needles seated slide float gauge Tool T109 126 between the top of the float at outer end and the air horn gasket as shown in Figure 16 The float should just touch the gauge 2 Check the other float in the same manner If an adjustment is necessary bend the float arm using Tool T109 22 until correct clearance has been ob tained After bending the arm test the float align ment Float Drop Setting 1 Holding the air horn in an upright position measure the distance from the top of floats outer end and the air horn gasket as shown in Figure 17 This measurement should be 1 2 inch If an adjust ment is necessary bend the stop tabs on the float levers until corr
86. properly bent and should be corrected Choke Unloader Adjustment 1 With the throttle valves in the wide open posi tion it should be possible to insert Tool T109 80 inch gauge between the upper edge of the choke valve and the inner wall of the air horn as shown in Figure 17 2 If an adjustment is necessary bend the un loader lip on the throttle shaft lever using Tool T109 41 until correct opening has been obtained Accelerator Pump Adjustment 1 Move the choke valve to wide open position to release the fast idle cam Back off the idle speed adjusting screw curb idle until the throttle valves are seated in the bores 2 Measure the distance from the top of the air horn to the top of the plunger shaft using a T scale as shown in Figure 18 This distance should be he inch 3 If an adjustment is necessary bend the throttle connector rod at the lower angle using Too T 109 213 until correct travel has been obtained 14 34 AFB CARBURETOR ACCELERATOR PUMP PLUNGER STEM SCALE R 7 CURB IDLE SPEED SCREW 3 BACKED OFF Fg THROTTLE FULLY CLOSED BEND THROTTLE CONNECTOR ROD AT THIS ANGLE 64x353 Fig 18 Testing the Accelerator Pump Adjustment Secondary Throttle Lever Adjustment 1 To measure the secondary throttle lever ad justment block the choke valve in the wide open position and invert the carburetor 2 Slowly open the primary throttle valves until it is possible to
87. rew through main body flange Se curely tighten Remove the ait horn as follows 1 Remove the spring clip and disconnect the choke operating rod 14 14 WWC3 CARBURETOR 2 Remove the hairpin clip and disconnect the fast idle rod 3 Remove the hairpin clip that holds the pump rod in the center slot of the pump arm Disconnect the pump rod 4 Remove the remaining two long screws and lift off the air horn Check the float setting as follows 1 Seat the float fulerum pin by pressing finger against the fulcrum pin spring There should be enough fuel in the bowl to raise the float so that the lip bears firmly against the needle Additional fuel may be admitted by slightly depressing the float If the fuel pressure in the line is insufficient to force additional fuel into the bowl add the necessary fuel from a clean container CAUTION Since the manifolds may be hot it is dangerous to spill fuel onto these surfaces Therefore take the necessary precautions to avoid spillage 2 With only the pressure from the buoyant float holding the lip against the inlet needle check the float setting using Tool 73725 or I scale There should be 5 inch from the surface of the bowl gasket removed to the top of the float at the center If an adjustment is necessary hold the float on the bottom of the bowl then bend the float lip toward or away from the needle using Tool 73605 Recheck the 54 inch setting again then repeat th
88. rs simultaneously set at the fast idle position 9 Connect both carburetor throttle rods to the bell crank Carburetor Air Cleaner Do Not Wash or Oil Every 5 000 miles remove filter element and blow out dirt gently with air hose Direct air from inside out and keep nozzle 1 inch away from element to avoid damaging Clean the metal housing and replace the element Every 15 000 miles install a new factory recommended filter element Service the unit more frequently when driving under severe conditions such as in dusty areas Twin 4 barrel AFB series 3505S carburetors are used on the Chrysler 300K Fig 4 These carburetors are basically the same as previous AFB carburetors The service procedures for disassembly cleaning in spection reassembly and adjustments are different and will be covered in detail The carburetor is equipped with a pair of velocity valves which are controlled by the secondary valve operation The throttle valves in the secondary half of the carburetor are mechanically connected to the primary valves and open with the primary after an approximate 60 degree lag and continue to open until both primary and secondary throttle valves reach the wide open position at the same time As engine Speed increases the forces exerted by the velocity of intake air down through the venturi permits the off set velocity valves to position themselves according to engine requirements FUEL AND INDUCTION SYSTEM 14 43 T
89. rted or restricted a new accelerator pump jet housing should be installed After test pour the gasoline from the carburetor bowl and remove pump plunger Air Horn Assembly 1 Slide the fuel inlet screen into the fuel line fitting then install fitting in air horn Tighten se curely 2 Inspect to see if the leather on the accelerator pump plunger is hard cracked or worn any sign of wear or deterioration is evident install a new plunger assembly 3 When reassembling make sure the large diam eter of the pivot screw enters the hole in the pump arm and that the shoulder of the screw has not pinched the pump arm 4 Place a new air horn to main body gasket in position on the air horn and install the float needle valve seats Be sure each needle seat and needle is reinstalled in its original position The carburetors are equipped with synthetic rub ber tipped fuel inlet needle The rubber tip is flexible enough to make a good seal on the needle seat and to give increased resistance to flooding NOTE The use of the rubber tipped needles re quire that care be used when making float adjust ments Avoid applying any pressure on the floats which might compress the tip of the fuel inlet needles The rubber tip can be compressed sufficiently to cause a false setting which will affect correct level of fuel in the bowl 5 Slide the right and left floats into position in the air horn and install the float fulerum pins
90. rubber grom met around the filler tube If cracked or deteriorated install a new grommet at reassembly Installation Before installing the tank gauge unit check the condition of the filter on the end of suction tube If the filter is plugged plastic will not corrode install a new filter 1 Position the fuel tank gauge unit in the tank using a new gasket Tighten securely using Tool C 3582 2 Slide the fuel tank under the vehicle Raise the tank far enough to engage the filler spout with the opening in the rear panel and the locator em bossments on the floor pan 3 Push the tank toward the rear to fully engage the filler spout in the opening STRAP TO FRONT OF CAR 4 60x97 Fig 2 Fuel Tank Mounting Town and Country FLOAT 57x275 Fig 3 Fuel Gauge Tank Unit 4 Hold the fuel tank in this position and place the hold down straps in position feeding the attach ing studs through holes in the end of the straps In stall the nuts but do not tighten 5 Guide the button head of the studs into the slots in the frame and down into position Tighten the hold down strap attaching nuts securely 6 Connect the lead wire to the tank gauge unit and reconnect the fuel line 7 Refill the tank and check for leaks ASSY Y FUEL TANK 14 53 2 FUEL TANK AND FILLER TUBE Imperial Removal CAUTION Disconnect the battery cable at the battery post befor
91. s returned to its original location Tighten securely using Tool 1109 57 Synthetic Rubber Tipped Fuel Inlet Needle The AFB carburetors are equipped with two syn thetic rubber tipped fuel inlet needles The needle tip is a rubber like material which is not affected by gasoline and is stable over a wide range of tempera tures The tip is flexible enough to make a good seal on the needle seat and to give increased resistance to flooding The use of the needles require that care be used when making float adjustments Avoid any pressure on the floats which might compress the tip of the needles The tip can be compressed sufficiently to cause a false setting which will affect correct level of the fuet in the bowl FUEL AND INDUCTION SYSTEM 14 47 ue THESE SURFACES MUST BE PARALLEL FUEL BAFFLE 64x343 MINIMUM CLEARANCE WITHOUT BINDING Fig 15 Measuring the Float Alignment Install the fuel inlet needles in their respective seats then install each float and fulcrum pin Be sure the marked float is installed on the pump side After the floats have been installed test the float alignment level and drop settings as follows Float Alignment Setting 1 Sight down the side of each float shell to deter mine if the side of the float is parallel to the outer edge of the air horn casting as shown in Figure 15 2 If the sides of the floats are not in alignment with the edge of the casting bend the float lever by ap
92. se If part is faulty replace Test the fuel or float level in the carburetor Ad just as necessary to obtain the correct float level Clean and inspect the needle valve and seat If found to be in questionable condition replace assembly Then test fuel pump pressure Refer to Specifications for correct fuel pump pressure Disassemble the Carburetor Replace the worn ac celerator pump and throttle linkage and measure for the correct position Test adjustment and operation of automatic choke If necessary replace the choke Disassemble the carburetor Replace the cracked body Make sure main to throttle body screws are tight Disassemble the carburetor Replace the faulty gaskets and test for leakage Be sure the screws are tightened securely 14 56 DIAGNOSIS FUEL SYSTEM SERVICE DIAGNOSIS Continued Condition Possible Cause Correction c High float level d Excessive fuel pump pressure Poor performance a Restricted air cleaner Mixture too rich b Leaking float c High float level d Excessive fuel pump pressure e Worn metering jet POOR COLD ENGINE STARTING Incorrect Procedure a Throttle must be opened to free choke system Best position for all temperatures and all conditions is 14 open Choke Valve Fails to a Chokethermostat adjust Close ment leaner than specified b Choke thermostat eorroded such that it has cracked and distorted lean Choke
93. should also exist between the kick and the open choke valve positions with the engine running If binding does exist the choke operating link has been improperly bent and should be corrected BEND AT THIS ANGLE 64 x 338 Fig T5 Bending the Unloader Tang 14 22 BBD CARBURETOR Choke Unloader Wide Open Kick 1 Hold the throttle valves in the wide open posi tion Insert Tool T109 31 or a 14 drill shank between the upper edge of the choke valve and the inner wall of the air horn as shown in Figure 14 2 With a finger lightly pressing against the valve a slight drag should be felt as the gauge is being withdrawn If an adjustment is necessary bend the tang on the fast idle lever using Tool T109 22 as shown in Figure 15 until the correct clearance has been obtained Bowl Vent Valve Adjustment 1 With the throttle valves at curb idle there should be inch clearance between the bowl vent valve and the air horn when measured at the center of the vent valve and the seat with a drill shank 2 If an adjustment is necessary bend the short tang on the vent valve operating lever using Tool T109 22 until the correct opening has been obtained Idle Speed Adjustment Curb Idle To make the idle speed adjustment the engine must be thoroughly warmed up A more reliable idle adjustment can usually be obtained if the car has been driven a minimum of five miles For best results it is recommended that a tachome
94. should also exist between the kick and the open choke valve positions with the en gine running If binding does exist the choke opera CHOKE VALVE WIDE OPEN CLEARANCE R ca CLEARANCE GAUGE OR DRILL AT WIDEST CHOKE OPENING LIGHT FINGER PRESSURE AGAINST CHOKE VALVE THROTTLE HELD IN WIDE OPEN POSITION BEND TANG ON THROTTLE LEVER LEVER AGAINST STOP Fig 21 Unleader Adjustment Wide Open Kick ting link has been improperly bent and should be corrected Unloader Adjustment Wide Open Kick Fig 21 1 Lightly hold the choke valve closed then open the throttle valves to the wide open position The choke valve should be open sufficiently to allow a 156 inch drill to be inserted between the choke valve and the wall of the air horn as shown 2 To adjust bend the tang on the throttle lever using Tool T109 214 until correct opening has been obtained 3 Hold the choke valve open and then open and close the throttle valves Failure to obtain full throttle operation indicates improper assembly 4 With the throttle valves held in an open posi BEND PUMP ROD AS REQUIRED AT UPPER ANGLE 64x238 Fig 22 Accelerator Pump Travel tion the choke valve should fall open freely There should be no bind throughout the entire travel of the choke mechanism Accelerator Pump Travel Fig 22 1 With the throttle valves fully closed measure the pump trave
95. st idle connector rod to the choke lever Disengage rod from lever then swing rod at an arc until it can be disengaged from the fast idle cam Ce IEEE Nou STEP UP PISTON oF ir TON COVER PLATE SEP UP PISTON SPRING Ps Es T E L x 63x609 Fig 5 Removing the Step Up Pistons 14 44 FUEL AND INDUCTION SYSTEM 4 Remove the step up piston cover plate screws and plates Hold a finger over plate when removing screws to prevent the piston and metering rods from flying out Remove the step up pistons and metering rods as shown in Figure 5 Remove the step up piston springs 5 Remove the choke cable bracket then remove the ten air horn attaching screws 1 screw recessed Then lift the air horn straight up and away from main body Be careful not to bend or damage the floats Remove the pump plunger spring from the pump well Disassembling the Air Horn Place the air horn in an inverted position on the bench mainly to protect the floats then disassemble as follows 1 Remove the float fulcrum pins then remove each float Before removing floats it is suggested that the float on the pump side be marked so that the floats can be installed in their original locations 2 Remove the two needle valves after marking the pump side for identification 3 Using a wide blade screwdriver or Tool T109 57 remove the needle valve seats Mark the pump Side seat for identifica
96. static Thermostatic Thermostatic Thermostatic Coil Spring Coil Spring Coil Spring Coil Spring Setting isl Notch Rich 2 Notches Rich On Index 2 Notches Rich FUEL PUMP VC 1 VC 2 VC 3 VY 1 Du EL Model M 3672S TYPO cee eee ee has reres essere nnne Diaphragm Number of Volves Rh HR A meme ih e 9 ht n 2 S MERE c cccc c ECCLE LLL LLLL LLL ALIA Camshaft Pump Pressure cies hh hase e eme hee 3V to 5 psi WALSAS 1303 e rl 14 4 WWC3 CARBURETOR BOWL VENT VALVE LONG STROKE SLOT NORMAL STROKE SLOT SHORT STROKE SLOT CHOKE VACUUM DIAPHRAGM ACCELERATOR PUMP LEVER DIAPHRAGM PLUNGER STEM VACUUM HOSE FAST IDLE ROD FAST IDLE CAM THROTTLE LEVER CURB IDLE SPEED ADJUSTING SCREW FAST IDLE SPEED ADJUSTING ELEVATING LEGS SCREW SET OF 4 FAST IDLE ADJUSTING SCREW AIR HORN CHOKE VALVE CHOKE OPERATING LINK Viti CHOKE LEVER FUEL INLET FITTING MAIN BODY IDLE MIXTURE SCREW 2 CHOKE VACUUM DIAPHRAGM T DISTRIBUTOR VACUUM ADVANCE TUBE FITTING CLOSED CRANKCASE VENT FITTING THROTTLE BODY 64x22 Fig 1 Carburetor Assembly WWC3 Series BEN MUI EP LO iL _l ls lslasqs s s s s9csqssli s iE SIE SE ME V A WWC3 CARBURETOR 14 5 FUEL SYSTEM PART 1 MODEL WWC3 STROMBERG CARBURETORS The WWC3 Series Stromberg c
97. tem to the retracted position will provide an additional hole for the removal of dirt Compressed air can be used to remove loose dirt but should not be connected to the vacuum inlet fitting IMPORTANT If the commercial solvent or cleaner recommends the use of a water rinse if should be HOT After rinsing all trace of water must be blown from the passages with air pressure It is further advisable to rinse all parts in clean kerosene or gasoline to be certain no trace of moisture remains Never clean jets with a wire drill or other mechanical means because the orifices may become enlarged making the mixture too rich for proper performance 3 INSPECTION AND REASSEMBLY Main and Throttle Body Casting 1 Slide the primary throttle valve or valves into their respective bores install new screws but do not tighten Be sure the idle speed adjusting screw is backed out Hold the valves in place with fingers fingers pressing on the high side of the valves 2 Tap the valves lightly with a screw driver to seat in the bores Holding the valves in this position tighten the screws securely Stake screws by squeezing with pliers 3 Install the two idle mixture adjusting screws and springs in the throttle body portion of the casting AFB CARBURETOR 14 29 The tapered portion must be smooth and straight If the tapered portion is grooved or ridged a new idle mixture adjusting screw should be installed to insure having correct
98. ter be used in this adjustment On vehicles equipped with automatic transmission loosen the nut in the sliding link of the carburetor to bellerank rod so that the stop in the transmission will not interfere with the free movement of the car buretor throttle lever 1 To make the idle speed adjustment turn the idle speed screw in or out to obtain 500 rpm On cars with air conditioning set the idle speed at 500 rpm With air conditioning ON be sure the choke valve is fully open and that the fast idle adjusting screw is not contacting the fast idle cam 2 Turn each idle mixture screw in or out to obtain the highest rpm While making the adjustment care fully watch the tachometer and notice that the speed can be decreased by turning the screws in either direction from the setting that gave the highest rpm reading 3 Readjust to 500 rpm with the idle speed screw With air conditioning ON 4 Turn each idle mixture adjusting screw in the clockwise direction leaner until there is a slight drop in rpm Turn each screw out counterclockwise richer just enough to regain the lost rpm This procedure will assure that the idle has been set to the leanest mixture possible for smooth idle This setting is very important Since the correct speed was originally set using the speed screw the speed obtained after finding the leanest smooth idle will probably be too fast 5 Readjust the speed screw to obtain correct idle speed R
99. ter being compressed the rubber tip is very slow to recover its original shape It is very important that the float lip be perpendicular to the needle or slanted not more than 10 degrees away from the needle when the float height is correct Air Horn 1 Test the freeness of the choke mechanism in the air horn The choke shaft must float free to operate correctly If the choke shaft sticks in the bearings or appears to be gummed from deposits in the air horn a thorough cleaning will be required 2 Remove the accelerator pump plunger from the gasoline slide the compression spring and spring seat over the shaft Install the assembly in the air horn and engage with the accelerator pump arm 8 Place a new gasket on the main body and install the air horn Install attaching screws and tighten securely When installing air horn be sure the leather on the plunger does not wrinkle or fold back 4 Engage the accelerator pump rod with the pump rocker arm and install loose end in the center hole of throttle lever Install hairpin clip to secure 5 Engage the fast idle connector rod in the fast idle lever and throttle lever Install Hairpin clip to secure Installing the Vacuum Diaphragm 1 Install the diaphragm assembly on the air horn and tighten the attaching screws securely 2 Install the choke operating link in position be tween the diaphragm plunger stem and the choke lever Install the clip to secure 3 Inspect t
100. the Main Metering Jets WWCS3 CARBURETOR 14 7 Cleaning Carburetor Parts The recommended solvent for gum deposits is de natured alcohol which is easily obtainable There are other commercial solvents however such as Metalelene which may be used with satisfactory re sults Check the throttle shaft for excessive wear in the throttle body If wear is extreme it is recommended that the throttle body be replaced rather than in stalling a new throttle shaft in the old body The choke diaphragm can be damaged by solvents Avoid placing the diaphragm assembly in ANY liquid Clean the external surfaces with a clean cloth or soft wire brush Shake dirt or other foreign ma terial from the stem side of the diaphragm Depress ing the diaphragm stem to the retracted position will provide an additional hole for the removal of dirt Compressed air can be used to remove loose dirt but should not be connected to the vacuum inlet fitting IMPORTANT if the commercial solvent or cleaner recommends the use of water as a rinse it should be HOT After rinsing all trace of water must be blown from the passages with air pressure it is further advisable to rinse all parts in clean gasoline or kerosene to be certain no trace of moisture remains Never clean jets with a wire drill or other mechanical means because the orifices may become enlarged making the fuel mixture too rich for proper performance 4 INSPECTION AND REASSEMBLY 1 During manufa
101. the pump passages Using a small clean brass rod hold the discharge check needle firmly on its seat Again raise the plunger and press downward No fuel should be emitted from either the intake or discharge passage 3 If fuel does emit from the intake passage dis assemble the intake check ball and reclean the pas sage Fuel leakage at the discharge check needle in dicates the presence of dirt or a damaged check needle Clean again and then install a new check needle Retest for leakage 4 If either the intake check ball or discharge check needle leaks after above test and service fix attempt to reseat as follows 14 30 AFB CARBURETOR Intake Check Ball Remove the accelerator pump check ball assembly and install a new check ball assembly Discharge Check Needle 1 With the discharge check needle installed in sert a piece of drill rod down on the needle Lightly tap the drill rod with a hammer to form a new seat Remove and discard old needle and install a new one Retest as described previously If the service fix does not correct the condition a new carburetor 1nust be installed 2 Install the accelerator pump discharge check needle jet housing and gasket Install housing and attaching screws Tighten screws securely 3 Press down on the accelerator pump plunger shaft and as the plunger is being depressed a clear straight stream should emit from each jet If the streams are identical if either one is dive
102. tion 4 Remove the pump arm pivot screw then dis engage the pump link by removing pump arm Slide pump plunger out of the air horn then remove spring seat and compression spring from pump shaft Dis card the air horn to main body gasket Place the accelerator pump plunger in a jar of clean gasoline or kerosene to prevent the leather from drying out 5 Remove the fuel inlet fitting nut and gasket then remove filter screen Disassembling the Main Body 1 Remove the accelerator pump jet housing screws then remove jet housing and gasket as shown in Figure 6 Invert the carburetor and drop out the discharge check needle 2 Using Tool T 109 58 remove the main metering jets from the primary and secondary side as shown in Figure 7 These jets are not interchangeable No 120 159 primary and No 120 158 secondary 3 Remove the screws that attach the primary venturi to the main body These venturi are not interchangeable side for side and it is suggested that the pump side venturi be marked for identification Remove the venturi as shown in Figure 8 Discard the gaskets The pump side venturi is numbered 687 The opposite one numbered 686 4 Remove the screws that attach the secondary CCELERATOR PUMP JET HOUSING MAIN METERING JET 2 PRIMARY 63 61 VENTURI PRIMARY VENTURI 7 PUMP SIDE 2 63x612 Fig 8 Removing the Primary Venturi VELOCITY VALVES 63x613
103. tor Pedal 1 Unsnap the accelerator pedal from shaft 2 Turn the threaded end of rod either in or out until a measurement of 114 degrees is obtained be tween the floor of car and the flat face of the acceler ator pedal 3 This measurement can be made with a spirit protractor 4 After correct measurement has been obtained reconnect rod Remove pin from accelerator shaft bracket FUEL AND INDUCTION SYSTEM 14 41 Setting the Bellcrank 1 Loosen locking nuts C and D left and right bank carburetor rods 2 Pivot the ballcrank until a 94 amp inch piece of welding rod 3 inches long can be inserted through the bellcrank hole and down into the locating hole in the intake manifold 3 Test each carburetor to be sure the choke valves are open that the fast idle cams are released and that the throttle valves are closed 4 Tighten locking nuts C and D securely Remove pin from bellcrank 5 Push rearward on the accelerator shaft to throt tle shaft lever rod adjusting link until stop is ob tained Tighten locking nut securely Idle Speed and Mixture Adjustment Connect a tachometer and warm up the engine to normal operating temperature Be sure the choke is fully off and that the engine is at curb idle trans mission in Neutral Proceed as follows 1 Turn the idle mixture screws from 1 to 2 turns open 2 Set the idle bypass air serews 2 turns open and adjust the idle speed to 700 rp
104. tributor testing machine with a vacuum source or vacuum supplied by another vehicle To make this adjust ment proceed as follows 1 With the engine Not running open the throttle valves far enough to allow the choke valve to be moved to the closed position 2 Disconnect the vacuum hose from the dia phragm and connect the hose from the vacuum supply as shown in Figure 11 A minimum of 10 inches of mercury HG will be required 3 Insert a 1 inch drill or gauge between the choke valve and the wall of the air horn Refer to Fig 11 Apply a slight closing pressure to the choke shaft to hold the drill or gauge in position 4 An adjustment will be necessary if a slight drag is not obtained as the drill or gauge is being removed The adjustment of this opening will require the removal of the choke operating link CAUTION DAMAGE TO THE DIAPHRAGM AND THE CHOKE LEVER SLOT CAN RESULT IF THE LINK IS NOT REMOVED FOR THE BENDING OP ERATION 5 Remove the clip and disengage the choke operating link from the diaphragm stem plunger then disengage the link from the choke lever The CHOKE OPERATING LINK Fig 12 Choke Operating Link Measurements best bending results will be obtained by using a vise and a pair of pliers 6 Bend the choke operating link to provide the correct choke valve opening CAUTION A correction in the length of the link of 010 inch will result in a change of 010 inch in the chok
105. ts should be made before removing the fuel pump from the vehicle 64 x 415 Fig 1 Fuel Pump Assembly Pressure Test If leakage is not apparent test pump for pressure as follows 1 Insert a ep fitting in the 1 fuel line at the car buretor as sHown in Figure 2 2 Connect 6 inch plece of hose between the T fitting and gauge Tool C 3411 The hose should not exceed 6 inches A longer hose may collect fuel and the additional weight would be added to the pressure of the pump and result in an inaccurate reading 3 Vent the pump for a fiw secorids this relieves any air trapped in the fuel chamber If this is not done the pump will not operate at full eapacity and a low pressure reading will result 4 Connect a tachometer then start the engine and run at 500 rpm The r ading should be from 3 to 5 psi The pressure Should remain constant or return t zero very very sl wly when the engine is stopped An ristant drop to zero indicat s a leaky outlet valve If the pressure is too low weak main spring or improper assembly of the diaphragm may be the cause If the pr ssure is too high the main spring is too strong Vacuum Test j The vacuum test should be made with th fuel line disconnect d from the carburetor This will allow the pump to operate at full capacity which it must do to prime a dry carburetor Fig 2 Pressure Testing the Fuel Pump The vacuum reading sh
106. ve and seat Worn accelerator pump and throttle linkage Automatic choke not operating properly Cracked body Faulty body gasket a b 9 a b e d e f g h a b Correction Disassemble the carburetor Then use compressed air to clear idle bleed after soaking it in a suitable solvent Disassemble the carburetor Then use compressed air to clear idle discharge holes after soaking the main and throttle bodies in a suitable solvent Disassemble the carburetor Inspect the throttle valve shaft for wear If excessive wear is apparent replace the throttle body assembly Replace the worn or damaged idle needle Adjust the air mixture Test the fuel level in the carburetor Adjust as necessary to obtain the correct float level Tighten the main body to throttle body screws se eurely to prevent air leaks and cracked housings Disassemble the carburetor Clean and inspect accelerator pump by pass jet Replace by pass if it is in questionable condition Disassemble the carburetor Replace accelerator pump assembly if leather is hard cracked or worn Test follow up spring for compression Disassemble the carburetor Use compressed air to clear the discharge nozzle and channels after soak ing the main body in a suitable solvent Test the fuel pump capacity Disassemble the carburetor Inspect the accelerator pump inlet check ball for poor seat or relea
107. y Lift out the jet housing and gasket as shown in Figure 3 Discard the gasket Invert the main body and drop out the discharge check needle from the discharge passage 2 Using Tool T109 58 remove the main metering jets secondary side as shown in Figure 4 NOTE The primary and secondary main meter ing jets are not interchangeable It is very important that these jets be installed in their respective loca tions in the main body at reassembly PRIMARY i PUMP SIDE PRIMARY VENTURI CHOKE SIDE 63x503 A uri Fig 5 Removing Primary Vent 14 28 AFB CARBURETOR 3 Using Tool T 109 58 remove the main metering jets primary side 4 Remove the screws that attach the primary venturi choke and pump side to the main body Lift the venturi straight up and away from the main body as shown in Figure 5 Discard the gaskets NOTE The venturi assemblies are not inter changeable side for side and must be re installed in their original location at reassembly 5 Remove the screws that attach the secondary venturi choke and pump side to the main body Lift the secondary venturi assemblies straight up and away from the body as shown in Figure 6 6 Using Tool T 109 59 screw driver bit remove the accelerator pump intake check ball assembly The check ball assembly is located at the front of the bowl at the base of the accelerator pump cylinder Be sure that the check ball is thoroughly cleaned before
108. y hold the floats on the bottom of the bowl then bend the float lip toward or away from the needle Recheck the 1 4 inch setting again then repeat the lip bending operation as re quired CAUTION When bending the float lip do not allow the lip to push against the needle as the rubber tip can be compressed sufficiently to cause a false setting which will affect correct level of fuel in the bowl NOTE After being compressed the rubber tip is very slow to recover its original shape It is very important that the float lip be perpendicular to the needle or slanted not more than 10 degrees away from the needle when the float is set correctly 5 After the float has been correctly set reassem ble the air horn FAST IDLE SPEED ADJUSTING SCREW ON k THE LOWEST STEP OF THE FAST IDLE CAM CHOKE VALVE WIDE OPEN FAST IDLE CAM 64 X 339 Fig 16 Fast Idle Speed Adjustment On the Engine Fast Idle Speed Adjustment On the Engine To set the fast idle speed on the engine connect a tachometer to the vehicle then set the curb idle speed and proceed as follows 1 With the engine running and the transmission in the neutral position open the throttle slightly 2 Close the choke valve about 20 degrees then allow the throttle to close Return the choke valve to the open position 3 The fast idle adjusting screw should be con tacting the lowest step on the fast idle cam as shown in Figure 16 4 With the eng

FUEL SYSTEM (PUMP, CARBURETOR, TANK)

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