pwrtrip75

iTrader: (8)

99 corvette, 6 speed.

I rebuilt the engine in my 99 vette last summer. stock rebuild but w/ 224/224 .580/.580 112 cam and headers, and 43# injectors. I tuned it w/ wideband and HP tuners.

Car dialed in perfectly... had no issues. A/F is right on, I can cruise in 4th at 30mph fine. Drove it for a couple weeks and all of a sudden the idle started staying at 2000rpms. While driving, while clutch is in, while stopped.

I put it away for the winter. Got it out today. Drove just fine on a 2 mile trip. Came home. got ready to take it to the car wash, it did the typical 10 second column lock error, pull key and wait 10 seconds. Then started it up and it was in high idle mode again at 2000rpms. Any ideas?

I just went out and hooked my laptop up to scan it..... the only codes are miscommunication w/ pcm in history. And some Brake thing affecting the TCS. Nothing else. And the car was idling normal again.

pwrtrip75

iTrader: (8)

Let the car sit an hour. Drove it about 3 miles, perfectly fine. beat on it a little, perfectly fine. So i decided to stop and shut it off and restart it......BAM. After its restarted it went into 2000rpm idle mode and stayed there.

edcmat-l1

iTrader: (10)

Data log of it doing it?

pwrtrip75

iTrader: (8)

Im going to go do that now. I dont have the WB hooked up anymore though.

pwrtrip75

iTrader: (8)

ok, drove it to the gym... was fine till I shut it off and restarted it half way there... then it went to high idle (attachment highidle1.hpl) was there for 45 min. Car started fine again, drove fine with no issues (attachment goodrun2.hpl) Then i shut it off half way home and restarted it...high idle again (highidle2.hpl) I did stop at a stop and sit for a minute, the idle was at 2200ish, and then after about 10 seconds returned to normal. Then stayed normal for the last few seconds of the log.


I noticed the Throttle position is always around 15% when its at high idle. My foot is not on the gas at all. When its idling normal i think it says like 9%

Higgs Boson

iTrader: (3)

Have you checked under the hood? Are you sure a mouse didn't make it a winter home?

pwrtrip75

iTrader: (8)

Ya, it did it right before i put it away also. What is weird is it only does it if I restart it. I started it this morning and drove to work fine. But if I had stopped and shut it off, it would have restarted in high idle mode.

edcmat-l1

iTrader: (10)

That really didn't tell me much. Gimme an email and I'll send you a config file to use.

pwrtrip75

iTrader: (8)

Thanks, PM sent w/ my email address.

Schitzo

iTrader: (6)

Subscribed.
I have had the same issue since August of last year. Mine is a 2004 LS1 with a cable TB. It will idle at 2000K rpm unless I disconnect the IAC. With the IAC disconnected, it idles fine.

I have done all I can do to fix this issue without any luck. Hope you can find what the issue is.

edcmat-l1

iTrader: (10)

Post a scan and tune. Probably an easy fix.

pwrtrip75

iTrader: (8)

I pulled a lot out of my Idle airflow table (10 across the whole table). Seems to have cleared it up. Now when I go to stop and push the clutch in it drops down to about 500rpms for a second then goes up to normal idle. I remember I messed with the throttle delay last year... probably have to play with it again.

Schitzo

iTrader: (6)

thanks I will start my own thread instead of jacking this one any further.