C 2500 Truck 2WD V8-5.7L VIN R (1997)
2. Remove the IAC valve attaching screws.
CAUTION: If the IAC valve has 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 the IAC valve in any liquid cleaner or solvent, as damage may result.
3. Remove the IAC valve assembly.
4. Remove the O-ring.
CLEANING AND INSPECTION PROCEDURE
1. Clean the IAC valve O-ring sealing surface, pintle valve seat, and air passage.
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Use the carburetor cleaner and a parts cleaning brush in order to remove carbon deposits. Follow instructions on the container.
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Do not use a cleaner that contains methyl ethyl ketone, an extremely strong solvent and not necessary for this type of deposit.
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Shiny spots on the pintle or seat are normal. They do not indicate misalignment or a bent pintle shaft.
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If air passage has heavy deposits, remove the throttle body for complete cleaning.
2. Inspect the IAC valve O-ring for cuts, cracks, or distortion. Replace if damaged.
NOTE: If installing a new IAC valve, replace with an identical part. The IAC valve pintle shape and diameter are designed for the specific
application.
3. Measure the distance A between tip of IAC valve pintle and mounting flange. If greater than 28 mm, use finger pressure in order to slowly retract
the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve.
MEASUREMENT PROCEDURE
NOTE: If installing a new IAC valve, replace with an identical part. The AC valve pintle shape and diameter are designed for the specific
application.
Measure the distance A between tip of IAC valve pintle and mounting flange. If greater than 28 mm, use finger pressure in order to slowly retract
the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve.
INSTALLATION PROCEDURE
2. Lubricate the IAC valve O-ring with clean engine oil.
2. Install the IAC valve assembly.
3. Install the attaching screws.
Tighten
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Tighten the IAC valve attaching screws to 3.0 Nm (26 lb. in.).
4. Install the electrical connector.
5. Reset the IAC valve pintle position.
5.1.Turn the ignition switch to the ON position for 5 seconds.
5.2.Turn the ignition switch to the OFF position for 10 seconds.
5.3.Start the engine.
5.4.Check for the proper idle operation.
