my idle air control valve was bad so i replaced it and now my car idles fine when engine is at optimal running temp. however, on a cold start (usually the first start of the day) my car idles at about 1700 rps, then will slowly come down after driving for a few min. then it will start to pulse (like when you disconnect your pcv valve kinda) up and down then after a few seconds it will drop down to 800 rpms and idle fine. does anyone else have this problem? or one similar to it?
i have the same issue and from what ive read its probly a vacuum leak
I’d say first go cheapest route possible and look for vacuum leaks.
Secondly I’d look at and clean the fitv, there’s some write-ups on how to clean them here.
i have a both fast idle valve and IACV for sale if anyone is interested. This may just be someone solutions.