I have a 92 accord. 2.2 engine with automatic transmission. I am having an idle surge in park after engine has warmed up . It also has rough shifting from park to neutral to drive while sitting in the driveway. I have taken the throttle body off and cleaned it. I have replaced the pcv and hose. I tightened the FIT (it had backed off a good bit). I took off the IAC and sprayed it out with cleaner and cleaned the screen in it. I bled all the air out of the radiator system. I sprayed carb cleaner around vacuum hoses and anywhere I thought there could be a possible vacuum leak. Once when the car's idle was surging, I tapped the IAC with the handle of a screwdriver and the surge quit. I also tapped the IAC on another occasion and it didn't change the idle surge.

Any help would be appreciated. Thank you superdave1992

 

Sounds like a vacuum leak. Put your finger over the IAC port in the throttle body, it will have some suction, see if the car stalls when you block it. If the car continues to run, you have a big vacuum leak somewhere.

"Tightening the FITV" is actually disabling it. You might have trouble getting the car to start and idle in cold weather without it. To fix it right, take it off and replace the o-rings (including the one in the white plunger).

 

It depends on how far you tighten it down. Over time it does back off a bit. If you ever buy one new, you can put a mark on it and after a few years you will see it has moved. Depending on how tight or loose it is is how much maximum air it lets in when wide open. I totally agree with you that the outer orings do wear out over time.

 

That's true, I should be more careful with my wording. It seems that "tightening the FITV" all the way down has become a common "fix" seen in many forums.

Tightening it and then backing off a few turns is what was intended. If it's left fully tightened then it will be disabled.