Cleaning IAC valve
 

When I was going through the motor, I took the idle air control valve (IAC) off and thought I had it cleaned up pretty well. Unfortunately, now that I've been driving it for awhile I've started to notice signs that I didn't get it cleaned adequately, I think. Perhaps I have higher expectations for a 17 year-old car than I should but it seems like it shouldn't be going *crank-crank-crank* brrrrup, brup, baaaaaahhh... when I start it. Of course, it only seems to do that when the motor is cold, which makes me think it's the IAC.
Anyhow, all that to say: does this sound like a sticky IAC problem and is there a better way to clean it than drowning it in brake cleaner and exercising it?

Re: Cleaning IAC valve
 

Sounds like a temperature sensor issue to me.

Re: Cleaning IAC valve
 

How so? Let me add it's been in the mid 80s to upper 90s here, so cold is a relative term. I have a data scanner, should I look for the temp sensor to be reading incorrectly?

Re: Cleaning IAC valve
 

You said it's worse when the engine is cold. 80°F is cold for an engine that runs at 200°F+. You could say the sensor kind of acts like a choke on an old carbureted engine on start up.

Re: Cleaning IAC valve
 

I'll take a look at how the temp sensor is acting tomorrow morning when it's cool out.

Re: Cleaning IAC valve
 

I checked the temp sensor yesterday when the engine was cold and found it to only disagree with the ambient temp sensor by about 4 degrees. Not really sure the problem lies there.

Any other ideas? For what it's worth, it's also throwing a P0441 - Powertrain check engine light "Evaporative Emission Control System Incorrect Purge Flow". Any chance that's related?

Re: Cleaning IAC valve
 

I think I may have found the problem. Had the car up on the rack at the muffler shop and found the O2 sensor was loose. Took a wrench to it and the bung spun off. Had the bung resealed while they were at it and now the car starts up and purrs like I expect it to. Strange to me that a small leak like that would cause it to act that way but I'm glad to have it fixed!