I just got my swap built by a friend z6 block y8 head high comp pistons y5 intake manifold and wire harness, got all gaskets no leak but it idles high and then drops and back up high an drops constantly , thinking it could be ecu? Or intake manifold since y5 is vtec-e?

 

Do you mean the idle is surging constantly?

 

What ECU? Any check engine lights?

 

sounds like common vacume leak or TPS

 

If surging I the word, yes, ecu doesn't have code but i think its y5 ecu we tried putting a p28 and it started going crazier same with p2p ecu, thinking of putting y8 intake mani and y8 harness,instead of y5 ..

 

 

in small part you can hear it rise and drop rise and drop, and then its drowed out by my friend messing wit it thinking it might be the iacv

 

HELP!!!!!!!!!! lol

 

if you put your finger over the valve cover breather hole it idles normal?? thats what it looks like in video

 

If thats true you have a vac leak into crankcase. I see you have a clear hose from pcv to intake mani. make you you have pcv installed or that its not bad. only thing i can think that would cause a vac leak into crankcase.

 

i put the y8 intake mani, and it revs up HIGH {straight} i switch the y5? ecu and put the p2p y8 ecu and it goes back to reving up and down.....WTF