Repair Pontiac Mid-size 1974-1983 Repair Guide

Carbureted Engines

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Idle mixture and idle speed adjustments are critical aspects of engine tune and exhaust emission control. It is important that all tune-up instructions be carefully followed to ensure good engine performance and minimum exhaust pollution. Through the succeeding model years covered in this guide, the different combinations of emissions systems on different engine models have resulted in a wide variety of tune-up specifications. See the "Tune-Up Specifications" chart at the beginning of this section. All models covered here have an emissions information sticker placed within easy sight in the engine compartment, giving timing, carburetor adjustment and other important tune-up information. If there is any difference between the specifications listed in this guide and those on your car's emissions sticker, always follow the specs on the sticker.

The following carburetor adjustment procedures are listed by year, carburetor type, and engine displacement and code where necessary (consult the "Engine Identification Code" chart in this guide), as many of the carburetors covered are used simultaneously by all four GM divisions. Other carburetor adjustments and maintenance are found in .

Idle mixture screws have been preset and capped at the factory. The caps should be removed only in the case of major carburetor overhaul, or if all other possible causes of poor idle have been thoroughly checked. If you must adjust the idle mixture, have the carbon monoxide (CO) concentration checked at a professional shop equipped with a CO meter. Mixture adjustments are included only where it is possible for the owner/mechanic to perform them.

IDLE SPEED & MIXTURE





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Fig. Fig. 1 Idle speed adjustment-1976 250 cu. in. 6-cylinder MV carburetor with idle solenoid



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Fig. Fig. 2 Slow idle adjustment-2-bbl. carburetor with idle solenoid



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Fig. Fig. 3 Slow idle adjustment-2GC 2-bbl. carburetor with A/C



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Fig. Fig. 4 Idle speed adjustment-2-bbl. carburetor without idle solenoid



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Fig. Fig. 5 Fast idle adjustment-1978 M2MC 2-bbl. carburetor



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Fig. Fig. 6 Idle speed adjustment-1977 4-bbl. carburetor without idle solenoid



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Fig. Fig. 7 Idle speed adjustment-1977 4-bbl. carburetor with idle solenoid



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Fig. Fig. 8 Idle speed adjustment-1980 2-bbl. carburetor with idle solenoid



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Fig. Fig. 9 Idle speed adjustment-1978-83 4-bbl. carburetors without solenoid



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Fig. Fig. 10 Idle speed adjustment-1980-83 2-bbl. carburetors with A/C



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Fig. Fig. 11 Idle speed adjustment-1978-83 4-bbl. carburetors with solenoid



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Fig. Fig. 12 Fast idle adjustment-1977 5210-C 2-bbl. carburetor



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Fig. Fig. 13 Fast idle adjustment-MV 1-bbl. carburetor



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Fig. Fig. 14 Fast idle adjustment-4-bbl. carburetors



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Fig. Fig. 15 Fast idle adjustment-M2MC-210 carburetor

1974 Models

All model carburetors in 1974 are equipped with idle limiter caps and idle solenoids. Disconnect the fuel tank line from the evaporative canister. The engine must be at running temperature, choke off, parking brake on, and rear wheels blocked. Disconnect the distributor vacuum hose and plug it. After adjustment, reconnect the vacuum and evaporative hoses.

6-250 (1-BBL. ROCHESTER MV)
  1. Using the hex nut on the end of the solenoid body, turn the entire solenoid to get 850 rpm for manual transmission models, and 600 rpm for automatic transmissions in Drive.
  2.  

V8-350 AND 400 (2-BBL.-ROCHESTER 2GC)
  1. Turn the air conditioning off, if equipped. Adjust the idle stop solenoid screw for 900 rpm on manual transmission cars, and 600 rpm on automatics (in Drive).
  2.  
  3. De-energize the solenoid and adjust the carburetor idle cam screw (on the low step of the cam) for 400 rpm on automatic models (in Drive), 500 rpm on 350 engines with manual transmissions.
  4.  

V8-350 AND 400 (4-BBL.-ROCHESTER 4 MC)
  1. Turn the air conditioning off, if equipped. Adjust the idle stop solenoid screw for 900 rpm on manual transmission cars, and 600 rpm on automatics (in Drive).
  2.  
  3. Connect the distributor vacuum hose. Position the fast idle cam follower on the top step of the fast idle cam and adjust the fast idle speed to 1300 rpm on manual transmission cars, and 1600 rpm on automatics (in Park).
  4.  

1975-76 Models
6-250 (1-BBL.-ROCHESTER MV)
  1. Idle speed is adjusted with the engine at normal operating temperature, air cleaner on, choke open, and air conditioning off (air conditioning on-1976 automatic transmission models). Hook up a tachometer to the engine.
  2.  
  3. Block the rear wheels and apply the parking brake.
  4.  
  5. Disconnect the fuel tank hose from the evaporative canister.
  6.  
  7. Disconnect and plug the distributor vacuum advance hose.
  8.  
  9. Start the engine and check the ignition timing. Adjust if necessary. Reconnect the vacuum hose. To adjust the idle speed, turn the solenoid in or out to obtain the higher of the two specifications listed on the decal. With the automatic transmission in Drive or the manual transmission in Neutral, disconnect the solenoid electrical connector and turn the 1 / 8 in. allen screw in the end of the solenoid body to the lower idle speed.
  10.  
  11. Place the shift lever in Drive on cars with automatic transmissions and have an assistant apply the brakes. On cars with manual transmissions, put it into Neutral.
  12.  
  13. Cut the tab off the mixture limiter cap, but don't remove the cap. Turn the screw counterclockwise until the highest idle speed is reached.
  14.  
  15. Set the idle speed to the higher of the two listed idle speeds by turning the solenoid in or out.
  16.  
  17. Check the tachometer and turn the mixture screw clockwise until the idle speed is at the lower of the two listed idle speeds.
  18.  
  19. Shut off the engine, remove the tachometer, and reconnect the carbon canister hose.
  20.  

V8-260 (2-BBL.-ROCHESTER 2MC)
  1. Apply the parking brake and block the rear wheels.
  2.  
  3. After making sure the timing is correct, connect a tachometer to the engine and run the engine until it reaches normal operating temperature.
  4.  
  5. Remove the air cleaner and disconnect its vacuum hose from the intake manifold. Plug the manifold fitting. Disconnect and plug the evaporative emission hose at the air cleaner.
  6.  
  7. Make sure the choke is open and the air-conditioner is turned off.
  8.  
  9. Disconnect and plug the vapor canister and EGR vacuum hoses.
  10.  
  11. Leave the distributor vacuum line connected: there is no line on California cars.
  12.  
  13. Adjust the curb idle screw to obtain the specified rpm. On cars equipped with manual transmissions, depress the dashpot and turn it to obtain 0.040 in. clearance between its stem and the throttle lever.
  14.  
  15. On air conditioned cars with automatic transmissions, adjust the idle speed-up solenoid as follows:
  16.  
  17. Turn the air conditioner on.
  18.  
  19. Disconnect the compressor wiring at the compressor.
  20.  
  21. Use the curb idle adjusting screw to adjust the idle speed to 650 rpm.
  22.  
  23. Reconnect the compressor wiring.
  24.  
  25. To adjust the idle mixture, proceed as follows:
  26.  

Idle mixture is preset at the factory and normally does not require adjustment. Adjust the idle mixture only in the case of major overhaul, throttle body removal, or when all other possible causes of poor idle condition have been thoroughly checked. If you find it necessary to adjust the idle mixture, have the CO concentration checked by a dealer or a garage with a CO meter.

  1. The engine should be at operating temperature, the timing should be set, choke open, EGR valve hose and air cleaner vacuum hose disconnected and plugged. Leave the distributor vacuum hose connected.
  2.  
  3. Remove the idle mixture screw caps, and lightly seat the idle mixture screws.
  4.  
  5. On automatic transmission cars, back the screws out five turns. On manual transmission cars, back the screws out six turns.
  6.  
  7. With the idle speed screw, set the idle to the following initial specifications:

    Manual transmission-1075 rpm
     
    Automatic transmission (in Drive)-610 rpm
     
    California Automatic (in Drive)-700 rpm
     

  8.  
  9. Turn each mixture screw 1 / 2 turn at a time until the specified curb idle speed is reached.
  10.  
  11. Install the air cleaner and reconnect all hoses.
  12.  

ROCHESTER 2GC 2-BBL.
  1. With the engine at normal operating temperature, remove the air cleaner and disconnect the air cleaner vacuum hose at the intake manifold. Plug the fitting with a clean rag.
  2.  
  3. Make sure the choke plate is open and the air conditioning is off.
  4.  
  5. Set the parking brake and block the drive wheels.
  6.  
  7. Disconnect the evaporative emission hose from the air cleaner.
  8.  
  9. Disconnect the hose from the EGR valve. Plug the hose to the carburetor with a golf tee or pencil.
  10.  
  11. Disconnect the distributor vacuum hose, and plug the hose to the carburetor as above.
  12.  
  13. Connect a tachometer to the engine.
  14.  
  15. With the timing properly adjusted, adjust the carburetor idle solenoid screw (with solenoid energized) so that the engine is turning 650 rpm (or the figure specified on the underhood sticker) or with the transmission in Drive. The solenoid is "energized" when the plunger is fully extended; disconnect the idle and solenoid lead and open the throttle slightly for this to occur.
  16.  


CAUTION
Any time the car is tuned with the transmission in gear, you must always have a helper in the car with his or her foot on the brake. The parking brake must be fully applied.

  1. Disconnect the carburetor solenoid. With the transmission again in Drive, adjust the solenoid screw so that the engine turns 550 rpm (or the figure specified on the underhood sticker).
  2.  
  3. Reconnect the distributor vacuum hose, evaporative emission and EGR hoses. Disconnect the tachometer.
  4.  

ROCHESTER M4MC AND 4MC 4-BBL.
  1. Run the engine to normal operating temperature. Remove the air cleaner and disconnect the air cleaner vacuum hose at the intake manifold. Plug the fitting with a clean rag.
  2.  
  3. Make sure the choke plate is open and the air conditioning turned off.
  4.  
  5. Set the parking brake and block the rear wheels. Connect a tachometer to the engine.
  6.  
  7. Disconnect and plug the carburetor hoses from the vapor canister and the EGR valve. Plug the hoses with golf tees or pencils.
  8.  
  9. With the timing adjusted properly, set the slow idle screw to obtain 550 rpm (non-California 350 and 455 cu. in. V8s) or 600 rpm (Calif.) in Drive. Adjust 400 V8s to 650 rpm in Drive. If the sticker specs vary from these, adjust to sticker specifications.
  10.  


CAUTION
When adjusting idle speeds with the vehicle in Drive, always have a helper in the car with his or her foot on the brake and the parking brake fully applied.

  1. Adjust the idle speed-up solenoid on 350 and 455 V8s with air conditioning on to 650 rpm. The A/C compressor wires must be disconnected at the A/C compressor, and the transmission must be in Drive.
  2.  
  3. Reconnect the compressor wires and reconnect all hoses.
  4.  

1977 Models
ROCHESTER 2GE AND 2GC 2-BBL.
  1. Run the engine to normal operating temperature. Block the rear wheels and firmly set the parking brake.
  2.  
  3. Disconnect and plug the distributor vacuum advance hose, vapor canister hose, and EGR vacuum hose, using golf tees or pencils.
  4.  
  5. Disconnect the emission hose from the air cleaner. Keep the air cleaner connected.
  6.  
  7. With the timing properly adjusted and the air cleaner attached, make sure the choke plates are open and the air conditioning is off. Connect a tachometer to the engine.
  8.  
  9. Place the transmission in Drive. Make sure you have a helper inside the car with his or her foot on the brake, and the parking brake fully applied. Adjust the idle speed screw until the engine is idling at the specified rpm (see underhood sticker or "Tune-Up Specifications" chart in this guide). On cars with an air conditioning idle solenoid (on carburetor), disconnect the air conditioner compressor clutch wire, and turn the air conditioning on. Adjust the screw on the idle solenoid so the engine idles at the speed specified "solenoid energized" idle speed.
  10.  
  11. Reconnect all hoses, and disconnect the tachometer.
  12.  

5210-C 2-BBL. (4-151) IDLE SPEED
  1. Run the engine up to normal operating temperature. Make sure the choke is fully open and the air conditioning is off. Connect a tachometer to the engine.
  2.  
  3. Set the parking brake and block the rear wheels.
  4.  
  5. Disconnect and plug the PCV hose from the evaporation canister.
  6.  
  7. Disconnect and plug the vacuum advance hose at the distributor.
  8.  
  9. Connect a timing light to the engine. Start the engine and put the transmission in Drive (automatic) or neutral (manual). Check the timing and adjust if necessary.
  10.  
  11. Unplug and reconnect the vacuum advance hose and adjust the idle speed.
  12.  
  13. Disconnect the electrical connection at the A/C override switch, located on the accelerator linkage bracket. Set the A/C to the on position. Momentarily open the throttle to allow the solenoid to fully extend, and adjust the solenoid screw to the specified idle rpm.
  14.  
  15. Reconnect the A/C override switch and turn the A/C off. Place the transmission in neutral or Park.
  16.  
  17. Adjust the fast idle speed as shown in the illustration.
  18.  
  19. Unplug and reconnect the PCV hose at the canister.
  20.  
  21. Shut off the engine and disconnect the tachometer.
  22.  

M4MC AND M4ME 4-BBL.
  1. Run the engine up to normal operating temperature. Make sure the choke is fully open and the air conditioning is off. Connect a tachometer to the engine.
  2.  
  3. Set the parking brake and block the rear wheels.
  4.  
  5. Disconnect and plug the hoses from the EGR valve and evaporation canister.
  6.  
  7. Start the engine and put the transmission in Park (automatic) or neutral (manual).
  8.  
  9. Disconnect the distributor vacuum advance line.
  10.  
  11. Connect a timing light and check the timing at the specified rpm; adjust if necessary.
  12.  
  13. Reconnect the vacuum advance line.
  14.  
  15. Place the transmission in drive (automatic) or neutral (manual). On A/C equipped cars, turn the A/C on and disconnect the electrical connector at the A/C compressor clutch. Momentarily open the throttle to make sure the solenoid plunger is fully extended. Adjust the solenoid screw to the specified rpm depending on engine. On manual transmission cars, adjust the idle stop screw to the specified rpm depending on engine.
  16.  
  17. Reconnect the A/C compressor clutch electrical connector and turn the A/C off. Unplug and reconnect the evaporation canister and EGR hoses. Shut off the engine and remove the tachometer.
  18.  

1978-80 Models
5210-C 2-BBL. (4-151) IDLE SPEED

Adjustments are the same as those for 1977 models.

6510-C 2-BBL. IDLE SPEED
  1. Run the engine to normal operating temperature. Turn the air conditioning off and connect a tachometer and timing light to the engine.
  2.  
  3. Set the parking brake and block the drive wheels.
  4.  
  5. Disconnect and plug the PCV hose at the vapor canister.
  6.  
  7. Disconnect and plug the vacuum advance hose at the distributor.
  8.  
  9. Place the transmission in Drive (AT) or Neutral (MT). Check, and if necessary, adjust the timing.
  10.  
  11. Connect the vacuum advance hose.
  12.  
  13. Manual transmission, without A/C: turn the idle speed screw to obtain the specified rpm. Manual transmission with A/C or automatic transmission with or without A/C: Turn the idle speed screw to obtain the specified rpm. Disconnect the wire at the wide open throttle switch located on the accelerator linkage. Set the A/C to on. Momentarily open the throttle to extend the solenoid plunger. Adjust the solenoid screw to obtain the solenoid idle speed specified on the underhood sticker.
  14.  
  15. Connect the PCV hose and remove the tachometer and timing light.
  16.  

2GC AND 2GE 2-BBL. IDLE SPEED
  1. Run the engine to normal operating temperature. Make sure that the choke is fully opened, turn the A/C off and connect a tachometer and timing light to the engine according to the manufacturers' instructions.
  2.  
  3. Set the parking brake and block the drive wheels.
  4.  
  5. Disconnect and plug the vacuum hoses at the vapor canister and EGR valve.
  6.  
  7. Place the transmission in Park (AT) or Neutral (MT).
  8.  
  9. Disconnect and plug the vacuum advance hose at the distributor.
  10.  
  11. Check, and if necessary, adjust the timing.
  12.  
  13. Connect the vacuum advance hose.
  14.  
  15. Cars with manual transmission, without A/C: turn the idle speed screw to obtain the specified rpm. Cars with automatic transmission, without A/C: open the throttle momentarily to extend the solenoid plunger. Turn the solenoid screw to adjust the speed to the curb idle rpm listed on the underhood sticker. Turn the idle speed screw to the specified rpm.
  16.  

Cars with A/C: Turn the idle speed screw to obtain the specified rpm. Disconnect the A/C compressor clutch wire. Turn the A/C on. Open the throttle momentarily to extend the solenoid plunger. Turn the solenoid screw to obtain the rpm specified on the underhood sticker. Connect the compressor clutch wire.

  1. Connect all hoses. Remove the tachometer and timing light.
  2.  

M2MC-210 2-BBL. IDLE SPEED
  1. Run the engine to normal operating temperature.
  2.  
  3. Disconnect the A/C compressor clutch wire, turn the A/C off, make sure that the choke is fully opened, place the manual transmission in Neutral, and the automatic transmission in Drive. Set the parking brake and block the drive wheels.
  4.  
  5. Disconnect and plug the vacuum advance hose at the distributor.
  6.  
  7. Check and adjust the timing.
  8.  
  9. Connect the vacuum advance hose.
  10.  
  11. Disconnect the purge hose at the vapor canister.
  12.  
  13. Cars without A/C: turn the idle speed screw to obtain the specified rpm. Cars with A/C: turn the idle speed screw to obtain the specified rpm, turn the A/C on, open throttle momentarily to extend the solenoid plunger and set the solenoid screw to obtain the rpm specified on the underhood sticker. Turn the A/C off.
  14.  
  15. Connect all hoses and remove the tachometer and timing light. Connect the compressor clutch wire.
  16.  

M4MC 4-BBL. IDLE SPEED
  1. Run the engine to normal operating temperature.
  2.  
  3. Make sure that the choke is fully opened, turn the A/C off and connect a tachometer and timing light to the engine according to the manufacturers' instructions. Set the parking brake and block the drive wheels.
  4.  
  5. Disconnect the purge hose at the vapor canister.
  6.  
  7. Disconnect and plug the EGR vacuum hose at the EGR valve. On 350 engines, plug the purge hose at the canister.
  8.  
  9. Place the transmission in Park.
  10.  
  11. Disconnect and plug the vacuum advance line at the distributor.
  12.  
  13. Check and adjust the timing.
  14.  
  15. Connect the vacuum advance line.
  16.  
  17. Place the transmission in Drive.
  18.  
  19. On cars without A/C: adjust the idle speed screw to obtain the specified rpm. On cars with A/C: disconnect the compressor clutch wire. Open the throttle momentarily to extend the solenoid plunger. Turn the A/C on and adjust the solenoid screw to obtain the rpm specified on the underhood sticker. Connect the compressor clutch wire and turn the A/C off.
  20.  
  21. Connect all hoses and remove the tachometer and timing light.
  22.  

2SE AND E2SE IDLE SPEED
  1. Run the engine until it reaches normal operating temperature.
  2.  
  3. Prepare the vehicle for adjustment as indicated on the emission label under the hood.
  4.  
  5. Check the ignition timing and adjust as necessary.
  6.  
  7. Reconnect the vacuum advance line.
  8.  
  9. With the A/C off, turn the idle speed screw to obtain the curb idle as specified on the emission label.
  10.  
  11. With the automatic transmission in Drive or the manual transmission in Neutral, disconnect the A/C compressor wire at the compressor and turn the A/C on.
  12.  
  13. Open the throttle slightly to extend the solenoid plunger.
  14.  
  15. Turn the solenoid screw to obtain the correct rpm.
  16.  
  17. Turn the engine off and reconnect the A/C compressor line and all hoses.
  18.  

IDLE MIXTURE

Changes in the idle system have made adjustment of the fuel mixture impossible without the aid of a propane enrichment system not available to the general public.

1981-82 E2MC/E2ME or E4MC/E4ME Idle Speed
  1. Set the parking brake and block the wheels.
  2.  
  3. Disconnect and plug the hoses listed on the underhood specifications label.
  4.  
  5. Check, and if necessary, adjust the timing.
  6.  
  7. Connect a dwell meter and tachometer to the engine.
  8.  
  9. Start the engine and let it warm at idle until a varying swell is noted. It is absolutely necessary for the engine to be operated for a length of time sufficient for coolant and oxygen sensors to operate.
  10.  
  11. Check the idle speed. If necessary, turn the idle screw to obtain the speed shown on the underhood sticker.
  12.  

On models with Idle Speed Control (ISC), no adjustment is possible.

  1. Place the transmission in Drive (AT) or Neutral (MT). Note the dwell reading on the 6-cylinder scale of the dwell meter. It should be varying between the 10°-50° marks. If not, do the following:
  2.  
    1. Shut the engine off. Cover the internal bowl vents and the bleed valve air inlets with masking tape. Cover the air horn with a cloth.
    2.  
    3. Align a 1 / 8 inch drill bit on the rivet head which holds the idle air bleed valve cover in place and drill only enough to remove the rivet head. Drive the remainder of the rivet out.
    4.  
    5. Remove the cover. Clean out any metal chips from the housing.
    6.  
    7. Remove the tape and cloth. Start the engine and let it idle in Drive (AT) or Neutral (MT). With the engine at full operating temperature, slowly turn the idle bleed valve until the dwell reading varies within the 25°-35° range on the meter. The valve is very sensitive, so turn it very slowly.
    8.  
    9. If the dwell reading cannot be attained, it will be necessary to adjust the mixture. Special equipment is needed for this procedure, and this is best handled by a professional mechanic.
    10.  


1981-83 Idle Mixture

This is a very complicated procedure which requires special factory service tools; it is best left to a professional mechanic with the proper equipment.

FAST IDLE



1974-76 1 MV 1-bbl. (6-250)
  1. Adjust the curb idle speed with the idle stop solenoid, according to the underhood decal and the "Idle Speed" adjustment procedure earlier in this section.
  2.  
  3. Place the carburetor cam follower (on the throttle lever) on the high step of the fast idle cam.
  4.  
  5. Carefully bend the cam follower tang in or out to adjust to the specified rpm.
  6.  


WARNING
Support the throttle lever when bending the idle tang.

1974-76 2GC 2-bbl.

The fast idle is present on some V8 engines when the slow idle is adjusted.

  1. Place the fast idle cam follower on the low step of the fast idle cam, against the shoulder of the next higher step.
  2.  
  3. Adjust the fast idle screw to obtain the following specified idle speeds: (with transmission in Park):

    900 rpm, 350 V8 (non-Calif.)
     
    1000 rpm, 350 V8 (Calif.)
     
    1800 rpm, 400 V8 (where adjustable)
     

  4.  

1974-76 4MC and M4MC 4-bbl.
  1. On 350 and 455 V8s, place the fast idle cam follower on the lowest step of the fast idle cam against the shoulder of the next highest step. Adjust the fast idle screw to 900 rpm in Park.
  2.  
  3. On 400 cu. in. V8s, place the cam follower on the highest step of the fast idle cam. Adjust the fast idle screw until the engine is turning 1800 rpm in Park.
  4.  
  5. Reconnect all hoses and install the air cleaner. Disconnect the tach.
  6.  

1977 Models Except 5210-C 2-bbl. (4-151)

No fast idle adjustment is necessary, as the fast idle is automatically adjusted when the curb idle is set.

1977 5210-C 2-bbl. (4-151)

Adjust the fast idle speed according to the accompanying illustration.

1978-80 Vehicles

The fast idle on all 231 V6 and some 305 V8 engines is automatically set when the curb idle adjustment is made. Refer to the emissions sticker under your car's hood for this specific application.

Prepare the engine and car according to the emissions sticker before proceeding with the steps below.

4-151 (5210-C 2-bbl.)

The fast idle speed is adjusted in the same manner as on 1977 models.

BUICK-BUILT 350 V8
  1. Set the cam follower on the specified step of the fast idle cam according to the emissions sticker. Disconnect the vacuum hose at the EGR valve on 2-barrel models and plug this.
  2.  
  3. Turn the fast idle screw out until the butterfly valves in the primary throttle boxes are closed. You can see this by looking down into the carburetor; the butterfly valves are at the bottom of the bores.
  4.  
  5. Turn the fast idle screw in to adjust the idle speed to specifications. On 4-barrel models, turn the fast idle screw in until it just contacts the lever, then turn it in an additional three turns. Adjust to specified rpm.
  6.  

PONTIAC BUILT V8
  1. After making all adjustment preparations according to the emissions sticker, place the transmission in Neutral.
  2.  
  3. Place the cam follower on the specified step of the fast idle cam.
  4.  
  5. Disconnect and plug the EGR vacuum hose, using a golf tee or pencil, at the EGR valve.
  6.  
  7. Adjust the fast idle speed screw to obtain the specified rpm.
  8.  

OLDSMOBILE BUILT V8

Since the carburetor tuning procedures vary by model and component application, the procedure given on the emissions sticker in the engine compartment should be followed.

1981-83 Vehicles

Carburetor adjustment procedures for 1981-83 models vary by model and component application. Follow the procedure on the underhood emissions sticker, using the diagrams included in this guide as reference.

 
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