LT1 idle surge/lope and runs like poop
03-13-2005, 07:24 PM
#1
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Thread Starter
Join Date: Mar 2005
Posts: 7
LT1 idle surge/lope and runs like poop
Ok after reading all 23 pages of posts to see if there is an issue similar to mine, I have run across a few familiar syptoms, but none that match close enough to help me. BTW this place has already taught me alot.
Anyway... I have a 94Z stone stock as the tag implies. A few weeks ago I started having an idle surge when sitting at a light . This went on for a few days and it only happened when the coolant was at operating temperature.
When the engine was coold, it ran like a bat outa hell.
Then I started getting a bucking and stuttering effect when I would accelorate and the idle surge and loping would get worse. I replaced the plugs and airfilter and it had no effect. I did the wires last year so I didn't subject myself to that torture yet. I took off the air inlet and cleaned up the throttle body as best I could without removing it and made darn sure I had the inlet tube back on without crimping it. I looked over the engine while running in the dark and saw very faint sparkage around the Ignition coil and coil wire, Took off the wire and cleaned it up and removed the coil ground wires and made sure they were clean and tight. Still have slight sparkage around the coil, but not the coil wire. None of this sloved the problem and since then it has become worse everyday, even to the point where it does it now with the engine cold and the bucking and stuttering is making my daily driver almost undrivable. I have seen reference to the coolant temperature sensor in a few posts and will try replacing this and the fuel filter and if I have to...the God forsaken plug wires. I bought a little code reader and plugged it in to the diagnostic port under the dash and get NADA. The ses light does work but all I get when plugging in the reader is to have the coolant fans come on. I called the code reader manufacturer and they told me I have a problem with my diagnostic circut, which I have no idea how to fix and my Haynes manual doesn't give me a clue. So could it be the coolant temp sensor or the coil or some other finicky sensor soemwhere.
This is a long post, but I tried to include all information I could think of.
Any help will be greatly appreciated and I promise to post the solution for others to use in the future. This site is a very valuable resource.
Anyway... I have a 94Z stone stock as the tag implies. A few weeks ago I started having an idle surge when sitting at a light . This went on for a few days and it only happened when the coolant was at operating temperature.
When the engine was coold, it ran like a bat outa hell.
Then I started getting a bucking and stuttering effect when I would accelorate and the idle surge and loping would get worse. I replaced the plugs and airfilter and it had no effect. I did the wires last year so I didn't subject myself to that torture yet. I took off the air inlet and cleaned up the throttle body as best I could without removing it and made darn sure I had the inlet tube back on without crimping it. I looked over the engine while running in the dark and saw very faint sparkage around the Ignition coil and coil wire, Took off the wire and cleaned it up and removed the coil ground wires and made sure they were clean and tight. Still have slight sparkage around the coil, but not the coil wire. None of this sloved the problem and since then it has become worse everyday, even to the point where it does it now with the engine cold and the bucking and stuttering is making my daily driver almost undrivable. I have seen reference to the coolant temperature sensor in a few posts and will try replacing this and the fuel filter and if I have to...the God forsaken plug wires. I bought a little code reader and plugged it in to the diagnostic port under the dash and get NADA. The ses light does work but all I get when plugging in the reader is to have the coolant fans come on. I called the code reader manufacturer and they told me I have a problem with my diagnostic circut, which I have no idea how to fix and my Haynes manual doesn't give me a clue. So could it be the coolant temp sensor or the coil or some other finicky sensor soemwhere.
This is a long post, but I tried to include all information I could think of.
Any help will be greatly appreciated and I promise to post the solution for others to use in the future. This site is a very valuable resource.
03-13-2005, 07:27 PM
#2
Registered User
Join Date: Nov 2003
Location: Warner Robins, GA
Posts: 10
Re: LT1 idle surge/lope and runs like poop
Sounds awfully close to what I'm having and it seems that it turned out to be the EGR valve.
http://web.camaross.com/forums/showthread.php?t=347989
I had the problem quite badly before finally getting a code too.
http://web.camaross.com/forums/showthread.php?t=347989
I had the problem quite badly before finally getting a code too.
03-14-2005, 07:56 PM
#3
Registered User
Thread Starter
Join Date: Mar 2005
Posts: 7
Re: LT1 idle surge/lope and runs like poop
Ok after posting that last night, I went down to the garage to further tinkering.
I thought if I encase my plug wires in that plastic wire casing, it would help to prevent any electric bleeding between wires or if they were too close to each other or metal they could be arcing on. When I pulled off one of the wires, I noticed a rust colored powdery substance inside the cap end that goes on the plug. I must have missed this last week when I changed the plugs and all the plugs seemed to be burning the same. there was no evidence of this anywhere on the plug or around the wire, not even on the outside of the cap. I replaced just this one wire and the whole problem seems to have ended.
No idle loping or surging, no bogg and stutter with acceloration. Even after the engine is up to running temp. Im going to drive it a few days before I convince myself its solved. I got on it pretty hard a few times on the way home from work today and it ran like a champ.
There is a very slight miss (maybe my imagination) at idle, but that could be my sparky ignition coil or my opti rotor and cap. Anyone else out there having this problem should replace plug wires. If it doesn't solve the problem, it sure won't hurt.
Thankyou all for the awesome brainstorming on this site. Ive learned alot about my LT1 from reading the various messages. I intend to keep visiting this board and learning more.
I thought if I encase my plug wires in that plastic wire casing, it would help to prevent any electric bleeding between wires or if they were too close to each other or metal they could be arcing on. When I pulled off one of the wires, I noticed a rust colored powdery substance inside the cap end that goes on the plug. I must have missed this last week when I changed the plugs and all the plugs seemed to be burning the same. there was no evidence of this anywhere on the plug or around the wire, not even on the outside of the cap. I replaced just this one wire and the whole problem seems to have ended.
No idle loping or surging, no bogg and stutter with acceloration. Even after the engine is up to running temp. Im going to drive it a few days before I convince myself its solved. I got on it pretty hard a few times on the way home from work today and it ran like a champ.
There is a very slight miss (maybe my imagination) at idle, but that could be my sparky ignition coil or my opti rotor and cap. Anyone else out there having this problem should replace plug wires. If it doesn't solve the problem, it sure won't hurt.
Thankyou all for the awesome brainstorming on this site. Ive learned alot about my LT1 from reading the various messages. I intend to keep visiting this board and learning more.
06-01-2005, 02:04 PM
#4
Registered User
Join Date: May 2005
Posts: 23
Re: LT1 idle surge/lope and runs like poop
I have experienced the same problem! I havent noticed any arching because I havent let the engine run in the dark. But it will show signs of higher idle speed when hot at a light and causes more brake pressure to be applied to keep the car from moving forward, along with the stumbling acceleration. The problem hasnt grown to the point where it does it all the time.. only when it is hot. I will change the plugs and wires and see if it changes it.
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