Ok so my high idle problem has returned. So a little backstory, the car sat forever while it was being prepped for paint and all the bodywork/stereo work i did. Anway upon receiving it back with all the work done i replaced the brake fluid, brakes, clutch fluid,antifreeze, and oil. Anyway the car ran fine for a month and then the thermostat stuck and car overheated...not to bad i limped it home and replace that and it ran fine again for another couple weeks. Then i would get constantly a highidle ranging from 3-4k. It was constant as long as the car was in neutral. Driving it would be fine. I have no CEL codes. I thought it would be the TPS so i changed that even though it seemed fine but it was the bad model so i changed it no luck. I then finally broke down and made a appointment at a dealer that said they would look at my car. The day i took it in the idle was suddenly fine but i took it anyway. The dealer changed their mine about working on the car due to the bodywork and paint job but said that i could plug it in and they would do the diagnostics. Everything was fine and the car did fine for another 2 months i think and then i moved back to Montana and left the car with a friend. Recently my friend who starts it for me said the high idle has returned. I'm out of options and the only thing i can think may be the problem is the IAC is bad. I did notice when i did the TPS that the IAC hose that connects to the intake seemed to have a white chalky type powder in it. Thus i think this is my next step but the IAC is expensive to replace new. Any ideas. Can you clean one of these with some kind of cleaner throttle body cleaner maybe. Any ideas would be greatly appreciated as i'm trying to diagnose this long distance so i can fix it when i go to pick it up.

Any ideas please let me know or if anyone has a low mileage used IAC for sale let me know

Thanks
JD

You can and should try to clean the IAC with a nasty solvent. Oil from the PCV can get up in there and gunk it all up. I'd try that first.