legacycentral bbs

91 Legacy 5mt

I was having some very mild erratic idle problems and read cleaning the idle air control valve might help. So I cleaned and cleaned and got everything back on and when I ran the car it would idle constantly, steady at 2500 rmp. Not really an idle is it? I checked PCV hose and vacuum lines to make sure everything was on right and no leaks. Ok that checks out. Maybe the iac is bad so I pull a used one from the junk yard clean it and put that one on. No dice. So all I've done is clean the iacv and now it idles at 2500. What happened? I have no CEL codes.

I tried reading the resistance of the solenoid it's at 10 ohms.
I checked the voltage to the solenoid it's 12.3
I removed the solenoid from the valve, but kept it plugged in and started it up and what do you know it runs at a perfect idle. As soon as i put the solenoid back on the valve it will go back to high idling. Is the solenoid bad? Keep in mind it worked fine until I cleaned it and I have tried 2 and both behave the same way. What's my next step?

How did you clean the valves? What solvent did you use? Maybe the way you're cleaning the valves destroys a gasket inside them or something. Can you get your hands on another one from a junkyard? If you can, try installing it without cleaning it.

The reciprocating type IAC valves are kind of finicky. So either the solvant you're using is eating the seals or they may have gotten put togethe incorrectly.