I have a 1994 honda del sol with idling problems. It mostly idles around 2000rpms and sometimes idles around 400-500. Any idea what could cause this?

 

You mean cold idle start up at 2k rpms? If so that's pretty normal. 400 is pretty low for a warmed up idle. Clean the fitv for cold start issue, and adjust idle screw for the warm one. But do it per spec, by unplugging IACV and turning the screw to your liking, pull negative battery cable for about 5 mins then put it back on. Hope this helps!

 

Post the CEL codes.

Clean the IACV and FITV.

 

Yes its normal for it to idle higher until engine comes to temp.

2x On cleaning IACV + FITV but remember to set the idle inside the FITV. And ALSO the idle screw described below.

P.S. When cleaning them out dont skimp on the new O-rings. No Autozone crap... they are good for some things. Gaskets arent one of them.

 

Well it will still idle at 2000 while engine is warm, but sometimes it drops to about 400 then goes back up to about 2000 right after.

 

Clean them and then report back.

 

You know he wont ha...