Idle Air Control (IAC) Valve Replacement

Throttle Body Assembly:

IAC Valve:

REMOVE OR DISCONNECT
1. Resonator.
2. Distributor ventilation vacuum line at air intake duct.
3. Electrical connector from Intake Air Temperature (IAT) sensor.
4. Air intake duct.
5. Electrical connector from Idle Air Control (IAC) valve.
6. IAC valve assembly attaching screws.
7. IAC valve assembly.

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

CLEAN AND INSPECT
Clean IAC valve O-ring sealing surface, pintle valve seat and air passage.

- The IAC valve may be cleaned using GM cleaner 1052626 or GM X-66A. Use a shop towel or parts brush to remove heavy deposits.
- Shiny spots on the pintle or seat are normal, and do not indicate misalignment or a bent pintle shaft.
- If air passage has heavy deposits, remove throttle body for complete cleaning.

Inspect IAC valve O-ring for cuts, cracks, or distortion. Replace if damaged.

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

INSTALLING A NEW IAC VALVE
If installing a new IAC valve, measure the distance between tip of IAC valve pintle and mounting surface. If greater than 28mm (1.1 inch), 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 (retracting a used IAC valve in this fashion can result in motor gear damage).

INSTALL OR CONNECT
1. Lubricate IAC valve O-ring with clean engine oil.
2. IAC valve assembly.
3. IAC valve attaching screws. Tighten to 3 Nm (27 lb in). Refer to Thread-Locking Material under this heading.
4. Electrical connector to IAC valve.
5. Air intake duct.
6. Electrical connector to IAT sensor.
7. Distributor ventilation vacuum line at air intake duct.
8. Resonator.
9. Reset IAC valve pintle position:
A. Depress accelerator pedal slightly.
B. Start and release accelerator pedal, run engine for five seconds.
C. Turn ignition "OFF" for ten seconds.
D. Restart engine and check for proper idle operation.