back pressure fixed idle?

Devlin · Post by **Devlin** » November 26th, 2005, 3:26 am

just wondering if this is possible....

in the fall i got a ZE (eventually) swap, but had to get the idle brought up from 600 to 1100 rpm because otherwise it would stall out constantly when idling (and no, not a vaccuum leak in the intake, went through that already, and this was different).

on the whole, the raised idle level fixed it, execpt occasionally i had to watch my tack to make sure it doesn't start to fluxuate on me and stall out. at the same time, my stock exhaust system was a mess, my flex pipe was rotting away, a hanger broke off and took a piece of pipe w/ it, and the pipe itself completely snapped between the cat and muffler.

i FINALLY got that all replaced (full stainless 2.25" magnaflow w/ high flow cat from flex pipe back) yesterday....now it may b too early to say still, but she runs ALOT smoother than before. it used to drop down to 500 rpm if i had it reved too high and put the clutch in....now i havn't seen it go below 1000 in idle.

i'm gonna give it a couple weeks to be sure, but does anyone thing that that was my problem the whole time, and now it should b safe to turn the idle back down to 600 - 700 rpm?

jschrauwen · Post by **jschrauwen** » November 26th, 2005, 5:47 am

Ian, for the little time it takes, why not do a complete TPS adjust. And after that, if that hasn't fixed the problem, than at least it's one thing eliminated from the process. Was a complete TPS done by yourself after the correct ZE install? When you did your idle adjustments, was the TEN/GRD jumped in the diag box also? Have a quick check of your timing. Since you've already eliminated the intake tube and vaccum lines as potential problems, there's not much left to look to.

Devlin · Post by **Devlin** » November 26th, 2005, 1:30 pm

before the engine swap, i did check the TEN/GRD...and it told me i had a dead O2 sensor (which is still dead), but now i have the ZE ECU, so it wouldn't do anything.
as for anything else, i didn't do anything myself. the guys who installed it adjusted the idle, and i'm not gonna mess w/ things i don't have at least an idea about since i need it for work.
unfortunately i won't make it to the kingston meet tonight since i have other plans (yay kegger), so i can't get u to show me...but i am going to keep an eye on it in the next few weeks cuz it IS already running better since the exhaust was installed, and i'm gonna have my mechanic look at a few other things soon anyway.

lakersfan1 · Post by **lakersfan1** » November 26th, 2005, 1:38 pm

Deimos wrote:before the engine swap, i did check the TEN/GRD...and it told me i had a dead O2 sensor (which is still dead), but now i have the ZE ECU, so it wouldn't do anything.

If your O2 sensor was dead before the swap, it's still dead now. That could definitely effect your idle, especially if your TPS is even slightly out of adjustment.

Devlin · Post by **Devlin** » November 27th, 2005, 10:28 pm

yes, it is still dead i know cuz i didn't bother getting it changed yet....but the thing is that the car runs better now. the only thing different is everything from the flex pipe back. but i'm gonna just keep an eye on it for a bit and then bring it down to 600 again and see if there's any probs

JM1EC-V6 · Post by **JM1EC-V6** » November 28th, 2005, 4:52 pm

Did you think about a stuck EGR valve (If your're using K8 Intake Manifold) ?

Check out the TPS Adjustment, and the BAC valve (IAC).

Good luck !