I recently got a used D16Y8 engine put into my 2000 Honda civic ex coupe and have had idling issues with it since I got it. It was indicating that it was the idle air control valve code on the check engine light and I replaced it but it still idles rough when I'm coasting. It used to jump between 1000 rpm and 2000 rpm before i reaced it now it still does it but not as often and it jumps between 1000 rpm and 1500 rpm.what else should I look into to stop the rough idle. Somebody told me I have to reset my computer. But I don't know.

 

Did you adjuct the IAC ?

 

No I just replaced it. How can I adjust it?

 

Sorry,i meant the fast idle control valve,take one screw out of the FIC valve and swivel the lid open,look inside and you will see either a screwhead or plastic ring,tighten the screw or plastic ring down snug,do no overthighten ! Reassemble if that dosent help you may have a vaccum leak.