Chrysler Full-Size Vans 1967-1988 Repair Guide

Feedback Carburetors

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ADJUSTMENTS



HOLLEY 6145

See Figures 1 and 2



Click image to see an enlarged view

Fig. Fig. 1: Holley 6145 electronic feedback carburetor for 1983-85 vehicles



Click image to see an enlarged view

Fig. Fig. 2: Holley 6145 electronic feedback carburetor for 1986-87 vehicles

IDLE SET RPM
  1. Disconnect and plug vacuum hose at the EGR valve and ground the carburetor switch with a jumper wire.
  2.  
  3. Disconnect and plug the 3 / 16 " diameter hose at the canister.
  4.  
  5. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  6.  
  7. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  8.  
  9. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  10.  
  11. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  12.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect O 2 sensor wire, hose to computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve.
  8.  

The idle speed with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST.

  1. Turn off engine and remove tachometer.
  2.  

SOLENOID IDLE STOP (SIS) RPM
  1. Disconnect and plug vacuum hose at the EGR valve.
  2.  
  3. Ground the carburetor switch with a jumper wire.
  4.  
  5. Disconnect and plug the 3 / 16 " diameter hose at the canister and remove the PCV valve from the valve cover and allow it to draw underhood air.
  6.  
  7. Connect a tachometer to the engine, start engine and let stabilize for two minutes.
  8.  
  9. Energize the solenoid by one of the following methods:
    1. Without air conditioning: Connect one end of a jumper wire to the solenoid wire and the other end to the battery positive post.
    2.  

  10.  

Use care in jumping to the correct wire on the solenoid. Applying battery voltage to the wrong wire will damage the wiring harness.

    1. With air conditioning: Press the air conditioning button on, set blower speed to low and disconnect the air conditioning compressor clutch wire.
    2.  

  1. Open throttle slightly to allow the solenoid plunger to extend.
  2.  
  3. Remove the adjusting screw and spring from the solenoid. Insert a 1 / 8 " allen wrench into the solenoid and turn to adjust to specified S.I.S. rpm.
  4.  
  5. Reinstall solenoid screw and spring and de-energize solenoid.
  6.  
  7. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  8.  
  9. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  10.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect the O 2 sensor wire, hose the computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve.
  8.  

The idle rpm with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST.

  1. Turn engine off and remove tachometer.
  2.  

PROPANE ASSISTED IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air-fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, otherwise:
    1. Remove air cleaner.
    2.  
    3. Disconnect all hoses from front of carburetor base.
    4.  
    5. Center punch at a point 1 / 4 " from end of mixture screw housing. The center punch mark should be indexed at about the 2 o'clock position.
    6.  
    7. Drill through outer housing at punch mark with a 3 / 16 " drill bit.
    8.  
    9. If the concealment plug does not pop out when the drill bit enters the plug cavity, use a small drift, punch or allen wrench to pry out plug. Save concealment plug for reinstallation.
    10.  

  2.  

Never place any tool against the mixture screw during this operation.

  1. Disconnect and plug vacuum hose at the EGR valve.
  2.  
  3. Ground the carburetor switch with a jumper wire.
  4.  
  5. Disconnect and plug 3 / 16 " diameter hose at the canister.
  6.  
  7. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  8.  
  9. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  10.  
  11. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  12.  
  13. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  14.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Disconnect the vacuum hose from the heated air door sensor at the carburetor and install the propane supply in its place.
  4.  
  5. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  6.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 11.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine turn the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 11-16. If okay, proceed to Step 18.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose and reinstall the vacuum hose that goes to the heated air door sensor.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire and reconnect radiator fan plug and reconnect O 2 system test connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the EGR valve.
  22.  

After Steps 18-22 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted.

  1. Turn engine off and remove tachometer. Reinstall the concealment plug.
  2.  

Holley 2280/6280

See Figures 3 through 8



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Fig. Fig. 3: Holley 2280 carburetor for 1980 vehicles



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Fig. Fig. 4: Holley 2280 carburetor for 1981 vehicles



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Fig. Fig. 5: Holley 2280 carburetor for 1982-83 vehicles



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Fig. Fig. 6: Holley 2280/6280 carburetor for 1984-86 vehicles



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Fig. Fig. 7: Holley 2280 Carburetor for 1987 vehicles



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Fig. Fig. 8: Holley 6280 carburetor for 1987 vehicles

IDLE RPM
  1. Turn off all lights and accessories.
  2.  
  3. Place transmission in Neutral or Park and set parking brake.
  4.  
  5. Start engine and run until operating temperature is reached.
  6.  
  7. Ground the carburetor switch with a jumper wire.
  8.  
  9. Disconnect and plug computer, EGR valve and 3 / 16 " diameter canister vacuum hoses.
  10.  
  11. Remove PCV valve from the valve cover and allow it to draw underhood air.
  12.  
  13. Disconnect wire from the O 2 sensor and ground it with a jumper wire. Let the engine run for 4 minutes before proceeding.
  14.  
  15. Connect a tachometer to engine.
  16.  
  17. Turn the screw on the solenoid and adjust engine speed to specified rpm as shown on the emission label.
  18.  
  19. Remove jumper wire from O 2 sensor harness connector and reconnect to O 2 sensor.
  20.  
  21. Reinstall PCV into valve cover.
  22.  
  23. Reconnect all vacuum hoses.
  24.  
  25. Remove jumper wire from carburetor switch.
  26.  

The idle speed with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST.

  1. Turn off engine and remove tachometer.
  2.  

SOLENOID IDLE STOP (SIS) RPM
  1. Turn off all lights and accessories, place transmission in Neutral or Park and set parking brake.
  2.  
  3. Start and run engine until operating temperature is reached.
  4.  
  5. Ground the carburetor switch with a jumper wire.
  6.  
  7. Disconnect and plug the EGR valve and 3 / 16 " diameter canister vacuum hoses.
  8.  
  9. Remove PCV valve from the valve cover and allow to draw underhood air.
  10.  
  11. Connect a tachometer to engine.
  12.  
  13. Energize the solenoid by one of the following methods:
    1. Without air conditioning: Connect one end of a jumper wire to the solenoid wire and the other end to the battery positive post.
    2.  

  14.  

Use care in jumping to the correct wire on the solenoid. Applying battery voltage to the wrong wire will damage the wiring harness.

    1. With air conditioning: Press the air conditioning button on, set blower speed to low and disconnect the air conditioning compressor clutch wire.
    2.  

  1. Open throttle slightly to allow the solenoid plunger to extend.
  2.  
  3. Remove the adjusting screw and spring from the solenoid. Insert a 1 / 8 " allen wrench into the solenoid and turn to adjust to specified SIS rpm.
  4.  
  5. Reinstall solenoid screw and spring until it lightly bottoms out and de-energize solenoid.
  6.  
  7. Remove and plug the vacuum hose from the computer.
  8.  
  9. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  10.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect the O 2 sensor wire, hose the computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve. The idle rpm with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST.
  8.  
  9. Turn engine off and remove tachometer.
  10.  

PROPANE ASSISTED IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air-fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, otherwise:
    1. Remove air cleaner and disconnect all hoses from front of carburetor base.
    2.  
    3. Center punch at a point 1 / 4 " from end of mixture screw housing.
    4.  
    5. Drill through at punch mark with 3 / 16 " drill bit.
    6.  
    7. Repeat operation on opposite side.
    8.  
    9. Pry out plugs and save for reuse.
    10.  

  2.  
  3. Turn off all lights and accessories.
  4.  
  5. Place transmission in Neutral or Park and set parking brake.
  6.  
  7. Start engine and run until operating temperature is reached.
  8.  
  9. Ground the carburetor switch with a jumper wire.
  10.  
  11. Disconnect and plug computer, EGR valve and 3 / 16 " diameter canister vacuum hoses.
  12.  
  13. Remove PCV valve from the valve cover and allow it to draw underhood air.
  14.  
  15. Disconnect wire from the O 2 sensor and ground it with a jumper wire. Let the engine run for 4 minutes before proceeding.
  16.  
  17. Connect a tachometer to engine.
  18.  
  19. Tee in propane supply hose in the vacuum line to the choke vacuum kick diaphrapm.
  20.  
  21. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  22.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 11.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw(s) until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine tune the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 11-16. If okay, proceed to Step 18.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire from O 2 sensor harness connector and reconnect O 2 sensor connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the computer, canister and EGR valve.
  22.  

After Steps 18-22 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted.

  1. Turn engine off and remove tachometer. Reinstall the concealment plug.
  2.  

Carter BBD

See Figures 9 through 14



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Fig. Fig. 9: Carter BBD carburetor for 1967-72 vehicles



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Fig. Fig. 10: Carter BBD carburetor for 1973-79 vehicles



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Fig. Fig. 11: Carter BBD carburetor for 1980-83 vehicles



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Fig. Fig. 12: Some Carter BBD carburetors had a tamper resistant choke rod cover



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Fig. Fig. 13: Carter BBD carburetor for 1984-87 vehicles without electronic feedback



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Fig. Fig. 14: Carter BBD carburetor for 1984-87 vehicles with electronic feedback

IDLE RPM
  1. Disconnect and plug vacuum hose at the EGR valve and ground the carburetor switch with a jumper wire.
  2.  
  3. Disconnect and plug the 3 / 16 " diameter hose at the canister.
  4.  
  5. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  6.  
  7. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  8.  
  9. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  10.  
  11. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  12.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect O 2 sensor wire, hose to computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve.
  8.  
  9. The idle speed with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST. Turn off engine and remove tachometer.
  10.  

SOLENOID IDLE STOP (SIS) RPM
  1. Disconnect and plug vacuum hose at the EGR valve.
  2.  
  3. Ground the carburetor switch with a jumper wire.
  4.  
  5. Disconnect and plug the 3 / 16 " diameter hose at the canister and remove the PCV valve from the valve cover and allow it to draw underhood air.
  6.  
  7. Connect a tachometer to the engine, start engine and let stabilize for two minutes.
  8.  
  9. Energize the solenoid by one of the following methods:
    1. Without air conditioning: Connect one end of a jumper wire to the solenoid wire and the other end to the battery positive post.
    2.  

  10.  

Use care in jumping to the correct wire on the solenoid. Applying battery voltage to the wrong wire will damage the wiring harness.

    1. With air conditioning: Press the air conditioning button ON, set blower speed to low and disconnect the air conditioning compressor clutch wire.
    2.  

  1. Open throttle slightly to allow the solenoid plunger to extend.
  2.  
  3. Turn the screw on the throttle lever to adjust to specified SIS rpm.
  4.  
  5. De-energize solenoid.
  6.  
  7. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  8.  
  9. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  10.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect the O 2 sensor wire, hose the computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve.
  8.  
  9. The idle rpm with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST. Turn engine off and remove tachometer.
  10.  

PROPANE ASSISTED IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air-fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, otherwise:
    1. Remove air cleaner assembly, vacuum hoses, throttle linkage, etc.
    2.  
    3. Locate and center punch on the side surface of the mixture screw housing 5 / 16 " from the front end of the housing in the center of both mixture screw housings.
    4.  
    5. Using a 3 / 16 " drill bit, drill at a right angle (90°) to the mixture screw housing through the outer surface of the housing.
    6.  
    7. Use a small drift, punch or allen wrench to pry out plug. Retain plug for reinstallation.
    8.  

  2.  

Never place any tool against the mixture screw during this operation.

  1. Disconnect and plug vacuum hose at the EGR valve.
  2.  
  3. Ground the carburetor switch with a jumper wire.
  4.  
  5. Disconnect and plug 3 / 16 " diameter hose at the canister.
  6.  
  7. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  8.  
  9. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  10.  
  11. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  12.  
  13. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  14.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Disconnect the vacuum hose from the heated air door sensor at the carburetor and install the propane supply in its place.
  4.  
  5. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  6.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 11.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine tune the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 11-16. If okay, proceed to Step 18.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose and reinstall the vacuum hose that goes to the heated air door sensor.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire and reconnect radiator fan plug and reconnect O 2 system test connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the EGR valve.
  22.  
  23. After Steps 18-22 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted. Turn engine off and remove tachometer. Reinstall the concealment plug.
  24.  

Carter Thermo-Quad®

See Figures 15 through 19



Click image to see an enlarged view

Fig. Fig. 15: Carter Thermo-Quad carburetor for 1979 vehicles-the 1975-78 Thermo-Quad carburetor is similar except without the bowl vent solenoid



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Fig. Fig. 16: Carter Thermo-Quad carburetor for 1980-81 vehicles-the 1973-74 Thermo-Quad is similar except without the bowl vent solenoid



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Fig. Fig. 17: Carter Thermo-Quad carburetor for 1982 vehicles



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Fig. Fig. 18: Carter Thermo-Quad carburetor for 1983 vehicles



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Fig. Fig. 19: Carter Thermo-Quad carburetor for 1984 vehicles

IDLE RPM
  1. Disconnect and plug vacuum hose at the EGR valve and ground the carburetor switch with a jumper wire.
  2.  
  3. Disconnect and plug the 3 / 16 " diameter hose at the canister.
  4.  
  5. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  6.  
  7. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  8.  
  9. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  10.  
  11. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  12.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect O 2 sensor wire, hose to computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve.
  8.  
  9. The idle speed with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST. Turn off engine and remove tachometer.
  10.  

SOLENOID IDLE STOP (SIS) RPM
  1. Disconnect and plug vacuum hose at the EGR valve.
  2.  
  3. Ground the carburetor switch with a jumper wire.
  4.  
  5. Disconnect and plug the 3 / 16 " diameter hose at the canister and remove the PCV valve from the valve cover and allow it to draw underhood air.
  6.  
  7. Connect a tachometer to the engine, start engine and let stabilize for two minutes.
  8.  
  9. Energize the solenoid by one of the following methods:
    1. Without air conditioning: Connect one end of a jumper wire to the solenoid wire and the other end to the battery positive post.
    2.  

  10.  

Use care in jumping to the correct wire on the solenoid. Applying battery voltage to the wrong wire will damage the wiring harness.

    1. With air conditioning: Press the air conditioning button on, set blower speed to low and disconnect the air conditioning compressor clutch wire.
    2.  

  1. Open throttle slightly to allow the solenoid plunger to extend.
  2.  
  3. Turn the screw on the throttle lever to adjust to specified SIS rpm.
  4.  
  5. De-energize solenoid.
  6.  
  7. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  8.  
  9. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  10.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect the O 2 sensor wire, hose to the computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve.
  8.  
  9. The idle rpm with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST. Turn engine off and remove tachometer.
  10.  

PROPANE ASSISTED IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air-fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, otherwise:
    1. Remove air cleaner.
    2.  
    3. Disconnect all hoses from front of carburetor base.
    4.  
    5. Center punch at a point 1 / 4 " from end of mixture screw housing. Use a 10 o'clock indexing on the right bank and 2 o'clock indexing on the left bank.
    6.  
    7. Drill through outer housing at a (90°) angle at punch mark and a 3 / 16 " drill bit.
    8.  
    9. Use a small drift, punch or allen wrench to pry out plug. Save concealment plug for reinstallation. Never place any tool against the mixture screw during this operation.
    10.  

  2.  
  3. Disconnect and plug vacuum hose at the EGR valve.
  4.  
  5. Ground the carburetor switch with a jumper wire.
  6.  
  7. Disconnect and plug 3 / 16 " diameter hose at the canister.
  8.  
  9. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  10.  
  11. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  12.  
  13. Remove and plug the vacuum hose from the computer. Connect an auxiliary vacuum supply to the computer and apply 16 in.Hg.
  14.  
  15. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  16.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Disconnect the vacuum hose from the heated air door sensor at the carburetor and install the propane supply in its place.
  4.  
  5. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  6.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 11.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine tune the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 11-16. If okay, proceed to Step 18.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose and reinstall the vacuum hose that goes to the heated air door sensor.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire and reconnect radiator fan plug and reconnect O 2 system test connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the EGR valve.
  22.  
  23. After Steps 18-22 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted. Turn engine off and remove tachometer. Reinstall the concealment plug.
  24.  

Rochester Quadrajet®

See Figure 20



Click image to see an enlarged view

Fig. Fig. 20: Rochester Quadrajet carburetor for 1985-88 vehicles

IDLE RPM
  1. Disconnect and plug vacuum hose at the EGR valve.
  2.  
  3. Ground the carburetor switch with a jumper wire.
  4.  
  5. Disconnect and plug the 16 diameter hose at the canister.
  6.  
  7. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  8.  
  9. Connect a tachometer to the engine.
  10.  
  11. Start engine and let speed stabilize for two minutes.
  12.  
  13. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  14.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for four minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to the specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect O 2 sensor wire.
  6.  
  7. Reinstall PCV valve.
  8.  
  9. Reconnect canister hose.
  10.  
  11. Remove ground wire from carburetor switch.
  12.  
  13. Reconnect hose to EGR valve.
  14.  
  15. The idle speed with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST. Turn engine off and remove tachometer.
  16.  

SOLENOID IDLE STOP (SIS) RPM
  1. Disconnect and plug vacuum hose at the EGR valve.
  2.  
  3. Ground the carburetor switch with a jumper wire.
  4.  
  5. Disconnect and plug the 3 / 16 " diameter hose at the canister.
  6.  
  7. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  8.  
  9. Connect a tachometer to the engine.
  10.  
  11. Start the engine and let speed stabilize for two minutes.
  12.  
  13. Energize the solenoid by one of the following methods:
    1. Without air conditioning: Connect one end of a jumper wire to the solenoid wire and the other end to the battery positive post.
    2.  

  14.  

Use care in jumping to the correct wire on the solenoid. Applying battery voltage to the wrong wire will damage the wiring harness.

    1. With air conditioning: Press the air conditioning button on, set blower speed to low and disconnect the air conditioning compressor clutch wire.
    2.  

  1. Open throttle slightly to allow the solenoid plunger to extend.
  2.  
  3. Remove the adjusting screw and spring from the solenoid. Insert a 1 / 8 " allen wrench into the solenoid and turn to adjust to specified SIS rpm.
  4.  
  5. Reinstall solenoid screw and spring until it lightly bottoms out. De-energize solenoid.
  6.  
  7. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  8.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Turn the screw on the solenoid and adjust to specified idle rpm as shown on the Emission Label.
  4.  
  5. Reconnect the O 2 sensor wire, hose to the computer, PCV valve and canister hose.
  6.  
  7. Remove ground wire from carburetor switch and reconnect hose to EGR valve.
  8.  

The idle rpm with the engine in normal operating condition (everything connected) may vary from set speeds. DO NOT READJUST.

  1. Turn engine off and remove tachometer.
  2.  

PROPANE IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air/fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, otherwise:
    1. Remove the carburetor.
    2.  
    3. Invert the carburetor and use a hacksaw to make two parallel cuts in the throttle body. Make cuts on each side of the locator points beneath the concealment plug. The cuts should reach down to the plug but should not extend more than 1 / 8 " beyond the locator points. The distance between the saw cuts will depend on the size of the punch to be used.
    4.  
    5. Place a flat punch at a point near the ends of the saw marks in the throttle body. Hold the punch at a 45° angle and drive it into the throttle body until the casting breaks away, exposing the steel plug.
    6.  
    7. Repeat the procedure for the other concealment plug.
    8.  
    9. Reinstall the carburetor.
    10.  
    11. Use Tool C-4895 (BT-7610B) or equivalent, to adjust the idle mixture screws.
    12.  

  2.  
  3. Disconnect and plug vacuum hose at the EGR valve.
  4.  
  5. Ground the carburetor switch with a jumper wire.
  6.  
  7. Disconnect and plug 3 / 16 " diameter hose at the canister.
  8.  
  9. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  10.  
  11. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  12.  
  13. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  14.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Disconnect the vacuum hose from the heated air door sensor at the carburetor and install the propane supply in its place.
  4.  
  5. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  6.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 10.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine tune the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 10-15. If okay, proceed to Step 17.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose and reinstall the vacuum hose that goes to the heated air door sensor.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire and reconnect radiator fan plug and reconnect O 2 system test connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the EGR valve.
  22.  
  23. After Steps 17-21 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted. Turn engine off and remove tachometer. Reinstall the concealment plug.
  24.  

Holley 2210

IDLE RPM
  1. Check and adjust the timing.
  2.  
  3. Disconnect the vacuum hose at the EGR valve.
  4.  
  5. Disconnect and plug the 3 / 16 " hose at the canister.
  6.  
  7. Remove the PCV valve from the valve cover.
  8.  
  9. Connect a tachometer.
  10.  
  11. Start the engine and run it to normal operating temperature.
  12.  
  13. Turn the idle speed control screw to adjust the engine rpm.
  14.  

PROPANE IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air/fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, otherwise:
    1. Remove the carburetor.
    2.  
    3. Invert the carburetor and use a hacksaw to make two parallel cuts in the throttle body. Make cuts on each side of the locator points beneath the concealment plug. The cuts should reach down to the plug but should not extend more than 1 / 8 " beyond the locator points. The distance between the saw cuts will depend on the size of the punch to be used.
    4.  
    5. Place a flat punch at a point near the ends of the saw marks in the throttle body. Hold the punch at a 45° angle and drive it into the throttle body until the casting breaks away, exposing the steel plug.
    6.  
    7. Repeat the procedure for the other concealment plug.
    8.  
    9. Reinstall the carburetor.
    10.  
    11. Use Tool C-4895 (BT-7610B) or equivalent, to adjust the idle mixture screws.
    12.  

  2.  
  3. Disconnect and plug vacuum hose at the EGR valve.
  4.  
  5. Ground the carburetor switch with a jumper wire.
  6.  
  7. Disconnect and plug 3 / 16 " diameter hose at the canister.
  8.  
  9. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  10.  
  11. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  12.  
  13. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  14.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Disconnect the vacuum hose from the heated air door sensor at the carburetor and install the propane supply in its place.
  4.  
  5. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  6.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 10.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine tune the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 10-15. If okay, proceed to Step 17.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose and reinstall the vacuum hose that goes to the heated air door sensor.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire and reconnect radiator fan plug and reconnect O 2 system test connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the EGR valve.
  22.  
  23. After Steps 17-21 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted. Turn engine off and remove tachometer. Reinstall the concealment plug.
  24.  

Holley 2245

See Figure 21



Click image to see an enlarged view

Fig. Fig. 21: Holley 2245 carburetor for 1982-84 vehicles-earlier 2245 and 2210 carburetors are similar

IDLE RPM ADJUSTMENT
  1. Check and adjust the timing.
  2.  
  3. Disconnect the vacuum hose at the EGR valve.
  4.  
  5. Disconnect and plug the 3 / 16 " hose at the canister.
  6.  
  7. Remove the PCV valve from the valve cover.
  8.  
  9. Connect a tachometer.
  10.  
  11. Start the engine and run it to normal operating temperature.
  12.  
  13. Turn the idle speed control screw to adjust the engine rpm.
  14.  

PROPANE IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air/fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, othersie:
    1. Remove the carburetor.
    2.  
    3. Invert the carburetor and use a hacksaw to make two parallel cuts in the throttle body. Make cuts on each side of the locator points beneath the concealment plug. The cuts should reach down to the plug but should not extend more than 1 / 8 " beyond the locator points. The distance between the saw cuts will depend on the size of the punch to be used.
    4.  
    5. Place a flat punch at a point near the ends of the saw marks in the throttle body. Hold the punch at a 45° angle and drive it into the throttle body until the casting breaks away, exposing the steel plug.
    6.  
    7. Repeat the procedure for the other concealment plug.
    8.  
    9. Reinstall the carburetor.
    10.  
    11. Use Tool C-4895 (BT-7610B) or equivalent, to adjust the idle mixture screws.
    12.  

  2.  
  3. Disconnect and plug vacuum hose at the EGR valve.
  4.  
  5. Ground the carburetor switch with a jumper wire.
  6.  
  7. Disconnect and plug 3 / 16 " diameter hose at the canister.
  8.  
  9. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  10.  
  11. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  12.  
  13. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  14.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Disconnect the vacuum hose from the heated air door sensor at the carburetor and install the propane supply in its place.
  4.  
  5. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  6.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 10.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine tune the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 10-15. If okay, proceed to Step 17.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose and reinstall the vacuum hose that goes to the heated air door sensor.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire and reconnect radiator fan plug and reconnect O 2 system test connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the EGR valve.
  22.  
  23. After Steps 17-21 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted. Turn engine off and remove tachometer. Reinstall the concealment plug.
  24.  

Holley 1945

See Figures 22 through 26



Click image to see an enlarged view

Fig. Fig. 22: Holley 1945 carburetor for 1978 vehicles-earlier 1945 carburetors are similar



Click image to see an enlarged view

Fig. Fig. 23: Holley 1945 carburetor for 1979-80 Federal and Canadian vehicles



Click image to see an enlarged view

Fig. Fig. 24: Holley 1945 carburetor for 1979-80 California vehicles



Click image to see an enlarged view

Fig. Fig. 25: Holley 1945 carburetor for 1981 vehicles



Click image to see an enlarged view

Fig. Fig. 26: Holley 1945 carburetor for 1982-87 vehicles

IDLE RPM
  1. Check and adjust the timing.
  2.  
  3. Disconnect the vacuum hose at the EGR valve.
  4.  
  5. Disconnect and plug the 3 / 16 " hose at the canister.
  6.  
  7. Remove the PCV valve from the valve cover.
  8.  
  9. Ground the carburetor switch with a jumper wire.
  10.  
  11. Connect a tachometer.
  12.  
  13. Start the engine and run it to normal operating temperature.
  14.  
  15. Turn the idle speed control screw on the idle solenoid to adjust the engine rpm.
  16.  

PROPANE IDLE MIXTURE

This procedure should only be used if an idle defect still exists after normal diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the air/fuel mixture should also be performed after a major carburetor overhaul.

  1. If the concealment plugs have already been removed, skip to step 2, otherwise:
    1. Remove the carburetor.
    2.  
    3. Invert the carburetor and use a hacksaw to make two parallel cuts in the throttle body. Make cuts on each side of the locator points beneath the concealment plug. The cuts should reach down to the plug but should not extend more than 1 / 8 " beyond the locator points. The distance between the saw cuts will depend on the size of the punch to be used.
    4.  
    5. Place a flat punch at a point near the ends of the saw marks in the throttle body. Hold the punch at a 45° angle and drive it into the throttle body until the casting breaks away, exposing the steel plug.
    6.  
    7. Repeat the procedure for the other concealment plug.
    8.  
    9. Reinstall the carburetor.
    10.  
    11. Use Tool C-4895 (BT-7610B) or equivalent, to adjust the idle mixture screws.
    12.  

  2.  
  3. Disconnect and plug vacuum hose at the EGR valve.
  4.  
  5. Ground the carburetor switch with a jumper wire.
  6.  
  7. Disconnect and plug 3 / 16 " diameter hose at the canister.
  8.  
  9. Remove the PCV valve from the valve cover and allow it to draw underhood air.
  10.  
  11. Connect a tachometer to the engine, start engine and let speed stabilize for two minutes.
  12.  
  13. Disconnect the engine harness connector from the O 2 sensor and ground the engine harness lead with a jumper wire.
  14.  

Care should be exercised so that no pulling force is put on the wire attached to the O2sensor. The bullet connector to be disconnected is approximately 4" from the sensor. Use care in working around the sensor as the exhaust manifold is extremely hot.

  1. Let the engine to run for 4 minutes to allow the effect of disconnecting the O 2 sensor to take place.
  2.  
  3. Disconnect the vacuum hose from the heated air door sensor at the carburetor and install the propane supply in its place.
  4.  
  5. Open the propane main valve. Slowly open the propane metering valve until maximum engine rpm is reached.
  6.  

When too much propane is added, engine speed will decrease. Fine tune the metering valve for the highest engine rpm. Also, if idle mixture is extremely rich, engine rpm will decrease with any amount of propane. In this case, turn the idle mixture screw in about1/2turn and repeat Step 10.

  1. With the propane still flowing, adjust the idle speeds screw on the solenoid until the tachometer indicates the specified propane rpm.
  2.  
  3. Fine tune the metering valve for the highest engine rpm. If there has been a change in the maximum rpm, readjust the idle speed screw to the specified propane rpm.
  4.  
  5. Turn off the main propane valve and allow the engine speed to stabilize.
  6.  
  7. Slowly adjust the mixture screw until the tachometer indicates the specified idle rpm. Pause between adjustments to allow the engine speed to stabilize.
  8.  
  9. Turn on the propane valve.
  10.  
  11. Fine tune the metering valve to get the highest engine rpm. If the maximum speed is more than 25 rpm different than the specified propane rpm, repeat Steps 10-15. If okay, proceed to Step 17.
  12.  
  13. Turn off both valves on the propane bottle.
  14.  
  15. Remove propane supply hose and reinstall the vacuum hose that goes to the heated air door sensor.
  16.  
  17. Remove the jumper wire from the carburetor ground switch.
  18.  
  19. Reinstall the PCV valve, remove the jumper wire and reconnect radiator fan plug and reconnect O 2 system test connector.
  20.  
  21. Unplug and reconnect the vacuum hose connector to the EGR valve.
  22.  
  23. After Steps 17-21 are completed, the curb idle speed may be different than the idle set rpm. This is normal and engine speed should not be readjusted. Turn engine off and remove tachometer. Reinstall the concealment plug.
  24.  

 
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