Okay I searched and read about 20 threads and it doesn't seem like any of them had my exact problem.

Here is my problem: My idle fluctuates between about 800 rpm and 1200 rpm. This only happens sometimes. If I'm driving my car around town, usually this won't happen. However if I go for a long drive (like 1.5-2 hours), usually by the time I get to my destination my car is doing this fluctuating idle thing.

2 weeks ago I was at the track (I had to drive 1.5 hrs to get there) and when I got there my car was having this fluctuating idle problem while in the staging lanes. The thing is though if I put my car in first and moved up about 2 car lengths and then went back into neutral, this would be enough to make it go away sometimes, other times it would stay. Also if I park my car and turn it off and start it up after like 5 minutes, it will be idling normal.

I used to have a stock B16 with an ITR throttle body, and after long drives it would do this too. Now I have a poor mans type r and it does it.

B18C1 w/ B16 head
AEBS manifold
Crower stage 2 cams
ITR tb
CTR crank pully
9.5lbs flywheel
Street tuned with Crome

Those are all the factors I think that can affect the idle. Im 99% sure there are no vaccuum leaks. When I was reading it said that I might need to bleed my coolant. Im sure my coolant needs to be bled, but can it really affect idle like that?

 

Clean your IACV.

 

what do u use to clean the IACV?? i have the same problem

 

Clean it with carb cleaner?