GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1996 🢒 Caprice 🢒 Engine 🢒 Engine Controls - 4.3L (Caprice Only) and 5.7L 🢒 Idle Air Control Valve Replacement

Removal Procedure

    Object Number: 35845 Size: SH
  1. Remove the resonator.
  2. Disconnect the distributor ventilation vacuum line at the air intake duct.
  3. Disconnect the electrical connector from the IAT sensor.
  4. Remove the air intake duct.
  5. Disconnect the IAC valve electrical connector.
  6. Remove the IAC valve attaching screws.
  7. Remove the IAC valve.

    8. Notice: 

       • Do Not push or pull on the IAC valve pintle on IAC valves that have been in service. The force required to move the pintle may damage the threads on the worm drive.
       • Do Not soak the IAC valve in any liquid cleaner or solvent, as damage may result.

  8. Clean the IAC valve O-ring sealing surface, the pintle valve seat, and the air passage.
    9. • Clean the IAC valve using GM cleaner 1052626 or GM X-66A. Use a shop towel or parts brush to remove heavy deposits.
    • If the air passage has heavy deposits, remove the throttle body for complete cleaning.
    • Shiny spots on the pintle or seat are normal, and do not indicate misalignment or a bent pintle shaft.
  9. Inspect the IAC valve O-ring for cuts, cracks, or distortion. Replace the O-ring if it is damaged.

Installation Procedure

    Object Number: 12637 Size: SH

    Important: If installing a new IAC valve, be sure to replace it with an identical part. The pintle shape of the IAC valve and the diameter of the IAC valve are designed for the specific application.

  1. Measure the distance between the tip of the IAC valve pintle and the mounting surface (1). If the distance is greater than 28 mm, use finger pressure to slowly retract the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve.

    2. Object Number: 35845 Size: SH
  2. Lubricate the IAC valve O-ring with clean engine oil.
  3. Install the IAC valve.
  4. Apply Loctite 262 to the IAC valve attaching screw threads if necessary.
  5. Install the IAC valve attaching screws.

    6. Tighten
    Tighten the IAC valve attaching screws to 3 N·m (27 lb in).

  6. Connect the IAC valve electrical connector.
  7. Install the air intake duct.
  8. Connect the IAT sensor electrical connector.
  9. Connect the distributor ventilation vacuum line to the air intake duct.
  10. Install the resonator.
  11. Reset the IAC valve pintle position.
    12. 11.1. Depress the accelerator pedal slightly.
    11.2. Start the engine.
    11.3. Release the accelerator pedal.
    11.4. Run the engine for 5 seconds.
    11.5. Turn the ignition OFF for 10 seconds.
    11.6. Restart the engine.
    11.7. Check for proper idle operation.