Rough Idle -- What to check first?
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Rough Idle -- What to check first? -- SOLVED ;-)
On my way in to work this morning, commute is around 30 miles one-way, car (2004 Vert) was running fine. 25 miles into the commute, I hit my first traffic light and noticed the car was idling very rough. Any speed over idle, runs fine. If I put in park and bring up to 1,000 or so RPMs runs smooth.
Only performance mods are Blackwing intake and LG headers w/ hi-flow cats. Intake has been on a year or so, headers intalled 7/29. Been running fine. Checked for codes, there are no codes.
Any ideas on what to check? I did get gas Sunday at an out-of-town Chevron, but not my usual location. Could this be a symptom of bad gas?
Thanks...
Only performance mods are Blackwing intake and LG headers w/ hi-flow cats. Intake has been on a year or so, headers intalled 7/29. Been running fine. Checked for codes, there are no codes.
Any ideas on what to check? I did get gas Sunday at an out-of-town Chevron, but not my usual location. Could this be a symptom of bad gas?
Thanks...
Last edited by 2K4Vert; Nov 29, 2006 at 04:25 PM.
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From: Baltimore suburbs Maryland
Vaccuum leaks, then make sure all the cylinders are firing. Like mentioned could be plugs too, but in my experience on a C5 bad plugs will idle OK but stumble under load at lower RPMs.
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any codes? Check plug wires, 02 wires, MAF (clean it), and also check the passenger side fuel injectory wiring harness, there's a bracket at the back left of the intake manifold that can rub through it and make the car run poorly.
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From: Simi Valley CA
Originally Posted by ericdwong
Vaccuum leaks, then make sure all the cylinders are firing. Like mentioned could be plugs too, but in my experience on a C5 bad plugs will idle OK but stumble under load at lower RPMs.
Look for intake leak AFTER the maf.
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From: Louisiana
Originally Posted by Cobra4B
any codes? Check plug wires, 02 wires, MAF (clean it), and also check the passenger side fuel injectory wiring harness, there's a bracket at the back left of the intake manifold that can rub through it and make the car run poorly.
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From: Louisiana
Thanks for all of the replies!!
Went back to the car, started it up, and let it idle. Same rough idle problem after sitting since around 7:00am. Rough part still stops at around 1,000 RPMs.
Checked for codes, and still no codes. Main concern now is whether it will stall on me on my way home.
Went back to the car, started it up, and let it idle. Same rough idle problem after sitting since around 7:00am. Rough part still stops at around 1,000 RPMs.
Checked for codes, and still no codes. Main concern now is whether it will stall on me on my way home.
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From: Grafton Ohio
Originally Posted by WKMCD
Get some electrical cleaner and clean the inside of the MAF - gently.
My $.02
My $.02
You probably have some air filter oil getting through the filter and settling on your maf. Remove the maf and clean it with some maf cleaner or electrical contact cleaner.
Jer.
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From: Louisiana
Originally Posted by jers98vet
You probably have some air filter oil getting through the filter and settling on your maf. Remove the maf and clean it with some maf cleaner or electrical contact cleaner.
Jer.
I just returned from some pretty high rev (not exceeding the legal speed limit but not using overdrive either) driving. Car pulls and sounds great at around 3,000 RPMs. I did, however, notice a lot of hesitation getting up to speed on the Interstate entrance ramp from a stop.
I'm still thinking "bad gas", but I'll try the maf cleaning. What is the brand for the cleaner and where do I get it?
One more thing, anyone have a write-up on how to clean the MAF?
Still no codes...
Thanks...
Last edited by 2K4Vert; Nov 27, 2006 at 10:31 PM.
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From: Louisiana
Originally Posted by zeevette
First thing is spark plug wires, then since you have headers, O2 sensors.
On the way home last night, I bought some MAF cleaner. So, since I took the day off to work on the car and fixed it in 2 minutes, I cleaned the MAF. No sign of crud. That thing is a PITA to get unplugged!!
Thanks again for the suggestions!!
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From: Louisiana
Originally Posted by jers98vet
Glad you fixed it and that it was a simple fix.
Jer.
Jer.
