So I did this conversion myself, read up on it first didn't see any thing bout extra wiring or anything but right away in morning the idle surges diff than any iacv I've heard so I'm guessing its the fiacv...ive swaped both them out with known good ones and both ohmed out fine. Swaped ecus, made sure all air pockets out of cooling system and still does it. Cept once in a while it won't do it and I rev the engine then it starts doing it again.

 

Is a vacuum hose disconnected or leaking?

 

That very well could be...but I sprayed every thing down with two cans if brake clean and didn't change....would a clogged pcv do this? If I unplug the iacv it stabilizis, didn't try driving it unplugged yet..Wats up with that

 

thermo/ hot idle start valve under throttle body, try swapping throttle bodies if you dont wanna tear it apart

 

I did that with a known good one