i have a 93 hatch with a b18a1 with gsr head, forged rods and pistons, with a garret 60 trim that ive been building for the past few months. When i bought the car it was ls vtec n/a and it had the same idle problem it would idle between 1000-1500rpms and it would jump up and down between there basically every second, that motor had a rod kncok and blew in my driveway. so i put a different b18a1 in it witht he gsr head, same setup just with the turbo. now i started the car yesterday and it had the same sporadic idle problem. so i put my ecu in my buddies 92 hatch with an ls, its a p28 chipped ecu and when we cranked his car over his car had the same sporadic idle. now the ecu also did this before it was chipped. is my ecu bad or what? any help is greatly appreciated.

 

it could be the tune. when its pig rich or lean it will try to find fuel or whatnot causing it to idle funny, or ecu is bad. or iacv, or if you have fast idle valve if you have one on your car but doubt it. hope that helps..

 

well i know its not the tune because it did this b4 the ecu was chipped. and the only reason i dont think its the iac is because my friends car did the same thing with my ecu in it. so i think im gonna shell out the cash for a new ecu but i just dont know yet. trying to get some more opinions. thanks for the input though.

 

well i just put a new ecu in with the same problem. what else could it be?

 

i have an 88 crx with the b18a1 swap and it does the same thing, i just got done with a top end rebuild and cleaned everthing out along with the IACV and FITV but still the idle bounces from 1000 to 1500