d16 idle issues

[hondaxpurt]

okay, i know this topic has been covered like 16748574 times, but i cannot figure this thing out. okay, car has a surging idle. 93 civic cx with a d16z6 swap. i have 3 iacv's, they all read good resistance through the valve. i replaced the iacv gasket, have checked EVERYWHERE for a vacuum leak, HG is good, bled the cooling system, and done everything i can think of. The upper hole in the throttle body has alot of vaccum when you put your finger on it, the bottom one does not. when you put your finger on that upper hole, it helps slow the surging. sometimes it will stop it, sometimes it will not. the car surges alot more when the air temp outside is cold than warm. it only surges when warm. the car threw a CEL for IACV, VSS, and vtec pressure switch, which im sure are all related. i am lost at what could be the problem. at this point, i am thinking maybe the ECU is tuned differently, as its a EPROM chipped ecu. thats the only other thing i can think of...REPS for help!!!

p.s. mods to car: intake, header, exhaust, adjustable FPR, high output coil, 60mm tb port matched to IM.

[pinedo88]

yea it might be the ecu . my buddy has a z6 wit a non vtec ecu and it was idlin low i let him borrow mine an it fixed it right away.

[pjay]

could be completely unrelated, you guys seem to be speaking of something totally different, but my car used to do that and it was just a vacuum hose leak, super easy fix that was putting a lot of stress on the car. i have a 2000 civic ex btw

[russky95]

i have the same problem on my 95 ex coupe... what i was told was that it is idle control valve or something to do with that? im still clueless... where was that leak at? maybe i have the same problem who knows

[CaTcH22]

Check that the connectors are going to the right sensors and not mixed up. Its easy to plug the wrong connectors to the wrong sensors. If it happened after the swap was done...

[k3tsurui]

this is like the 30th time i've said this and it has like a 80% success rate......replace the pvc valve, the hose that connects to the pvc to the shit box behind the block and the vacuum attachment to that box.....use honda parts/don't buy auto part pvc shit (ive seen some to be like 30 mil off factory spec). all the parts will cost you like 35 bucks from honda but it will make your life so much better


i dont see how the vtec pres switch code is related (which makes me think that you might have a simple plug in the wrong spot issue)...not saying that this works with all cases, but you did say you've tried everything but i dont see you list this...if for nothing then at least you did some good maint work. but anyways gl and let me know if it works

[Turbodude06]

Check that the connectors are going to the right sensors and not mixed up. Its easy to plug the wrong connectors to the wrong sensors. If it happened after the swap was done...

this is like the 30th time i've said this and it has like a 80% success rate......replace the pvc valve, the hose that connects to the pvc to the shit box behind the block and the vacuum attachment to that box.....use honda parts/don't buy auto part pvc shit (ive seen some to be like 30 mil off factory spec). all the parts will cost you like 35 bucks from honda but it will make your life so much better


i dont see how the vtec pres switch code is related (which makes me think that you might have a simple plug in the wrong spot issue)...not saying that this works with all cases, but you did say you've tried everything but i dont see you list this...if for nothing then at least you did some good maint work. but anyways gl and let me know if it works

^x2 on both good luck buddy. I wouldn't say ecu yet cause it wasn't doing it before when u had the ecu right?