i recently just put a poormans into a gsr shell and it has a type-R manifold and TB. but when i started it up after about 4 mins the car would start surging like a vacuum leak. i know its not the TB because we put it on my buddies car and it worked fine. and i know its not the IACV becauase we tried it on my friends car. could it be a ECU problem?? i was running a p72 ECU. please help me out

 

any CEL's?

sounds like a vacuum leak, possibly a cracked intake manifold gasket or IACV gasket

 

Check if you have any codes. If you had a disconnected or broken vacuum lines your car would'nt be surging, a big vacuum leak would make your car idle higher.

 

i checked the CEL's and it said TPS and IACV. if it was a vacuum leak wouldnt it start surging right away?? it doesnt start surging until its warm

 

clean out your IACV, and FITV that is located on the throttle body

 

i just cleaned out the IACV imma try cleaning the FITV

 

goodluck cleaning the FITV..its a b*tch trying to get to it..i had enough stress getting the IACV by myself and having big arms you can barely fit your arms anywhere in the engine bay