GM S10/S15/Sonoma Pick-Ups 1982-1993 Repair Manual

Idle Air Control Valve



See Figure 1

  1. Disconnect the negative battery cable.
  3. Disengage the electrical connector from the idle air control valve.
  5. Loosen and remove the threaded IAC control valve and gasket using either a 1 1 / 4 in. (32mm) wrench, J-33031, or equivalent.

To install:

Before installing a new idle air control valve, measure the distance that the valve extends (from the motor housing to the end of the cone); the distance should be no greater than 11/8in. (28mm). If it is extended too far, damage may occur to the valve when it is installed.

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Fig. Fig. 1: Threaded IAC valve mounting-4.3L engine

  1. Measure the valve pintle extension. To retract the pintle on a NEW valve, use firm thumb pressure and, if necessary, rock the pintle with a slight side-to-side motion. BUT, if reinstalling a used valve on which the pintle is extended further than specification, an IAC tester MUST be used to electrically retract the pintle.

Do not attempt to physically retract a pintle on an IAC valve that has been in service, the force may damage the pintle threads. The force required to retract the pintle is only safe on NEW IAC valves.

  1. Install the IAC valve and gasket to the throttle body and tighten to 13 ft. lbs (18 Nm).
  3. Engage the valve electrical connector.
  5. Connect the negative battery cable.
  7. Reset the IAC valve pintle:
    1. There are 2 possible methods to resetting the IAC valve. First, depress the accelerator pedal slightly, then start and run the engine for 5 seconds. Shut the engine OFF for 10 seconds, then restart it and check for proper idle operation. If this does not work, start and run the engine until it reaches normal operating temperature. Drive the vehicle and the IAC valve will reset once vehicle speed is above 35 mph.