Cold Engine miss?
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From: Lethbridge, Alberta, _______Canada._______ West Coast Bonneville Fest ___05,06,07 Survivor___

Alright, its done this since the day I bought it, but I'm just getting around to asking now.
When its cold, weather its -30 or 70 above out, makes no diffrence. Usually happens on initial start up. I start it, it idles itself up to 1200 then slowly back down to 700 or so, but u can feel it missing, its like its almost running on 5.5 cylinders, its not like pulling a plug wire off and running it like that, usually once your driving its fine, like at red lights and all. Every now and then when its hot it will idle like that, u can feel the miss shake the car slightly, my msd coils and wires didnt make a diffrence, as the stockers did the same thing...any suggestions, im going to scan it for codes as well, hopefully that might lead me somewere...any ideas though?
When its cold, weather its -30 or 70 above out, makes no diffrence. Usually happens on initial start up. I start it, it idles itself up to 1200 then slowly back down to 700 or so, but u can feel it missing, its like its almost running on 5.5 cylinders, its not like pulling a plug wire off and running it like that, usually once your driving its fine, like at red lights and all. Every now and then when its hot it will idle like that, u can feel the miss shake the car slightly, my msd coils and wires didnt make a diffrence, as the stockers did the same thing...any suggestions, im going to scan it for codes as well, hopefully that might lead me somewere...any ideas though?
Thread Starter
Senior Member
True Car Nut
Joined: May 2003
Posts: 8,135
Likes: 1
From: Lethbridge, Alberta, _______Canada._______ West Coast Bonneville Fest ___05,06,07 Survivor___

they are the factory gap settings and they are the basic AC delco stock ones, there new.
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Joined: Feb 2005
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From: Ocean County, New Jersey

I seem to be having the same exact problem. On intial start up the idle sometimes will be real rough for a few seconds but when im driving or idling at a light its fine. I just changed my spark plugs too, i switched to the NGK'*. I put them in as they were gapped because I was told they are already pregapped. I didnt have this problem before I did the plugs so I am kinda short for ideas.
If the issue is only there when you first start it and goes away after driving for a bit I would think it has to do with air/fuel delivery. Once its warmed up and the o2 sensor kicks in the pcm can make adjustments as necessary. But when its cold and not listening to the o2 sensor any issues will show up more.
Tough to say though, sometimes these things end up something you'd never think of. I'd suggest hooking up a scantool and watching your o2 mv. Short of that maybe go over all the hoses and bend them to check for small cracks.
Just a thought
Tough to say though, sometimes these things end up something you'd never think of. I'd suggest hooking up a scantool and watching your o2 mv. Short of that maybe go over all the hoses and bend them to check for small cracks.
Just a thought
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southernengineerin
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Apr 4, 2010 07:19 PM



