Surging @ Idle ???
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,650
Likes: 7,292
From: CT
Surging @ Idle ???
Ok, I've had this problem before and it turned out to be a NUMBER of things. I had a bad MAF, a bad IAT, and later my IAT harness had to be re-soldered. Now I am having idle problems again, or at least they are starting up.
Noticed it today. Went to the movies with my girlfriend. We met there after work. Well, I had stopped for food first after meeting with a fellow named Jim who is kindly giving me his old set of tires to help limp me through the summer until the Lemon Law goes through. Anyway, I got to the theatre and was parked waiting while I ate. The idle was hopping from ~900 to ~350 and back. It was as if someone were slowly playing with the throttle, but my feet weren't even on the pedals. Just sitting there in neutral with the e-brake on (which also is shot, go figure).
This happen to anyone else? And it wasn't momentary. The car was fully warmed up, plenty of fuel, etc. But the computer kept bobbing the idle for some reason.
All I can think is "what now?" since they haven't yet finished fixing the LAST slew of problems. Bear in mind that the car is a stock 32k with nothing but SLP cat-back.
Noticed it today. Went to the movies with my girlfriend. We met there after work. Well, I had stopped for food first after meeting with a fellow named Jim who is kindly giving me his old set of tires to help limp me through the summer until the Lemon Law goes through. Anyway, I got to the theatre and was parked waiting while I ate. The idle was hopping from ~900 to ~350 and back. It was as if someone were slowly playing with the throttle, but my feet weren't even on the pedals. Just sitting there in neutral with the e-brake on (which also is shot, go figure).
This happen to anyone else? And it wasn't momentary. The car was fully warmed up, plenty of fuel, etc. But the computer kept bobbing the idle for some reason.
All I can think is "what now?" since they haven't yet finished fixing the LAST slew of problems. Bear in mind that the car is a stock 32k with nothing but SLP cat-back.
Melting Slicks
Joined: Dec 2001
Posts: 2,040
Likes: 0
From: Collin County Texas
Re: Surging @ Idle ??? (Brett C5 SCCA)
Have you tried the idle relearn procedure? I had a similar situation after I put in my 3500 rpm Vigilante. The idle would like to hover around 500 rpm's and after coming down from cruise rpm's, it would head for 500, wander around there and even died once. I did the relearn procedure and it seemed to help somewhat. However, I just got LS1_Edit and I raised the idle 150 rpm's. That solved it and now the idle stays no lower than 600 rpm's and no hunting.
Burning Brakes
Joined: Jun 2000
Posts: 1,112
Likes: 95
From: Blue Springs MO
Re: Surging @ Idle ??? (Brett C5 SCCA)
I had the exact same problem. After much frustration, I found a hose on on the engine passenger side that hooked in just before the throttle body that had come loose (might have been me during one of my cleaning frenzies). Reconnected and all was fine.
[Modified by Jim Shearer, 12:31 PM 7/10/2002]
[Modified by Jim Shearer, 12:31 PM 7/10/2002]
Melting Slicks
Joined: Dec 2001
Posts: 2,040
Likes: 0
From: Collin County Texas
Re: Surging @ Idle ??? (Jim Shearer)
Open up the "Search" tab on the forum page top and type in "Idle Relearn". I think it will come back with at least 3-4 past posts on this. One of them is detailed pretty good.
http://www.ls1.com/pcmidle.htm
http://www.ls1.com/pcmidle.htm
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,650
Likes: 7,292
From: CT
Re: Surging @ Idle ??? (Brett C5 SCCA)
I tried the relearn process before washing the car just now. No dice. Checked for possible vacuum leaks before the TB, etc. Also solid, no problems there. However, the idle today was ok again. Maybe the problem has passed. Last time it existed for the better part of 6 months. GM could not figure it out. Then they finally picked up on the MAF, etc. Problem was never 100% cured and the idle will do this maybe 3 times a week now. No battery problems now, either. I guess I'll just keep watching it.
