Snap-on says the IAC counts should be between 60 and 150 when the engine is on but not running. When at idle with a warmed up engine, IAC counts should be between 9 and 20. If they are above 20, cleaning the idle air control circuits is recommended. Be careful with solvents around rubber and electrical parts. Snap-on recommends GM top engine cleaner (105262), AC/Delco cleaner (X66-A) or an equivalent cleaner that does not contain methylethylketone. The service manual explains this in more detail and also gives the torque values for reassembly. Use new gaskets when reassembling otherwise you risk air leaks. (I think the throttle assembly gasket kit was $10 at my local AC/Delco distributor.)

Be careful you don't force the pintel in; you can ruin an IAC motor this way.

There were design problems with early idle air control motors. If yours is original, it might be easiest to just replace it (for about $65). According to Snap-on, the updated IAC motors have a black pintel spring and part number 17112351.

There's a simple test for a stuck IAC motor; there should be an RPM "flare up" when you first start the engine. If you have a scan tool, you can check to see if the IAC counts follow this.

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Craig Leres