What up all. Having the typical up and down idle issue usually associated with the IAC valve. Went to a junkyard and pulled three off of other civics and tried them all with the issue still remaining. Thinking next check should be a vacuum line check, any recommendations?

 

Fitv needs to be tightened down or you have a vacuum leak.

 

Does it need to be adjusted just for a high or a low idle, or for that and a loping idle? It idles real high when the IAC is connected and lopes when I disconnect it and its been running a while. its pretty inconsistent too, some days are better than others.

Any better ideas to check for vacuum leaks other than soapy water?

 

Just tighten the plastic down til its barely snug.

And use carb or throttle cleaner if the problem doesnt go away.

 

The crazy up-and-down is from the FITV leaking. Tightening it down seems to help some people, but if you take out the cylinder completely by unscrewing it, you'll see there's a rubber o-ring on the thing that is undoubtedly rock hard and not doing its job.

I took the o-ring to NAPA and they were able to match up one for 99 cents. The regular black o-rings or the green refrigerant o-rings both work.