So it's basically like the question says. I had a weird idle - it wouldn't fluctuate too much but it would choose random spots to idle at. Somedays it would idle at 1400, other days at 1200 and other times at 900. I cleaned the IACV with brake cleaner and a wire brush. re-installed it and nothing changed.

When I was testing it today, the car was fully warmed up and was idling at 1200. I blocked the iacv opening and the car dropped to an extremely stable ~750. I should mention I was using an OBD scanner to watch RPM and not trying to eyeball it from my tach. Just to make sure that there wasn't some vacuum leak from beyond the throttle body, I also blocked the entire throttle body and the car stalled as expected.

The only thing I can think of is that I destroyed the IACV bearing when I was cleaning it. I tried to re-lube it (and it spun great at the time) but maybe that didn't last.

Should I be looking to just replace the IACV or is there some other problem that could cause these symptoms?

 

you used new gaskets that are correct? Nothing blocking the air passageway to the IACV

 

IACV relearn done? Must be done anytime the iacv is cleaned

 

I used a new gasket on the IACV because I managed to tear it when I took the IACV off the throttle body. I didn't change the throttle body gasket but I think that one's fine because the car instantly stalls when I block the throttle body. My thinking was that if 500 rpms worth of air was making it in through some vacuum leak after the TB, I should be able to block the TB and still have the car idling at 4 or 5 hundred rpm.

 

I might give it a shot. I did the idle relearn after I put everything back together but I might have not let it idle long enough. I was thinking of trying it again and letting the car idle for close to 10 minutes just to be safe.

 

I can't remember the exact time, I think it's 2 fan cycles or something along those lines, but I'm sure there's a sticky on how to do it