? about iacv

[rockinthefans]

Im sure this is covered somewhere but really couldn't find what I was looking for. I've been having some problems with my a/f ratio on my 92 hatch. i was messing with stuff the other day redoing some vacuum lines and i unplugged the yellow plug on my iacv. nothing happened. First off, what exactly is the yellow plug go to? Second, shouldn't my car have died or at least tried to stumble or something. I'm leading to believe my iacv my be stuck open. Its been running lean for a while now. it idles fine just wants to stumble a lot when under a heavy load. i say it idles fine, its a little rough at times but not bad. anyway, can anyone help me out?

[nismoracingsx]

You answered part of your own question. All the iac is for is allowing some air past the throttle plate when the throttle is closed. That wouldn't cause you to stumble or run excessively lean since its supposed to be open at idle anyways. I would check the fuel system if you're getting a stumble under load. GL

[rockinthefans]

I've got 4 new injectors, new z32 fuel filter, fuel pressure regulater is working, and fuel pressure is at 36psi (spec is 34psi at idle). I'm kinda leaning towards a faulty tps after some more research. Could that cause a lean condition tho? And could somebody explain to me "fail safe mode"?

[nismoracingsx]

fail safe mode is when the pcm inserts default values and ignores the actual readings from the sensors. Might default to this mode if certain parameters keep failing. Test the tps w/ a multimeter, just search for the specs . And a bad tps can cause stumbling during accel. GL

[vancouverbc]

yellow plug goes to aac valve. unplugging doesnt do anything dramatic to how car runs for some reason.