Okay so a few weeks ago I decided to do something about the cold start idle problems on my 91 Legacy. I cleaned the IAC valve and PCV lines as suggested. And what do you know? The car now idles fine with a cold start, but will maintain the high 2.5rpm idle even when warmed up. Keep in mind, before I touched it it idled perfect when warm.

Today I pulled an old iacv out of a wrecked and swapped it in mine and it didn't do a bit of good. Still idles like it's cold. Any suggestions what could be wrong?

ECU may need a reset.

 

Did you mess with the solenoid on top of the valve any?

Maybe try removing the solenoid and make sure the valve moves easily. (just flip it back and forth with your fingers, should be smooth as butter) Be sure to mark it's position so it can be installed back in the same place.

 

Did you disconnect any vacuum hoses when you did the cleaning? Double check that they are connected tightly and aren't split.

Make sure the EGR valve is operating properly. Check for vac leaks.

 

 

nipper

Indeed I did mess with the solenoid and it seems to move just fine and dandy. I don't think I have an adjustable solenoid. It's just 2 screws and 2 holes and I replaced the solenoid with the valve. I'll try to pull codes tomorrow to see if I get anything first I have to research how to do it.

Make sure the EGR valve is operating properly. Check for vac leaks.

 

 

nipper

 

no EGR on a 1st gen OBD1

ECU does not throw any codes. NO vacuum issues. Everything checks out. The only thing I touched was the IACV so the issue must lie there. Wonder why the new one I put in didn't help? Could the MAF sensor cause this and if so wouldn't that throw a code? When I pull the intake line to the iac it idles low as it should. When I turn off the engine it doesn't shut off right away, but does some dieseling. Wish I would have never messed with this.