Rough Idle probs.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 43
From: Auburn MA
Rough Idle probs.
My car is idling rough now and smells like its running rich. I dont know if its because of the rain we have been getting recently or what. But When I first start it up it doesnt idle rough but as it gets to opperating temp it starts idling rough. The Car is a 94 coupe 6 speed and its only when its idling that it runs rough going down the road it smooths out and it doesnt break up or throw any check engine lights
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
How are the injectors? Have you ohmed them hot and cold or leak tested them. Also you might want to pull some plugs and take a look.
EDIT: How old is the opti?
EDIT: How old is the opti?
Last edited by RRT vette; Jul 13, 2006 at 07:18 PM.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 43
From: Auburn MA
The Opti as far as i know has never been replaced. The light came on on my drive home for a couple minutes just now but then shut off. I havent tried anything to diagnose it yet.
Burning Brakes
Joined: Jul 2005
Posts: 758
Likes: 6
From: Gainesville, FL
Originally Posted by RRT vette
Sounds like an o2 sensor. You are sure there are not codes?
Your (Impala Balko's) description is exactly how my car ran before the right side O2 completely went south. It had some oil leak onto it...
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Melting Slicks
Joined: Jan 2002
Posts: 2,531
Likes: 35
From: Lecanto Florida
Don't know if your newer Vette has the same componants as my 87, but while I was on the Power Tour mine started with a rough idle. Had it diagnosed by GM Performance (which followed the tour) as a bad IAC (Idle Air Controller part #70). They cleaned it but only helped a little. When I got home I ordered and installed a new kit (parts #70 & #71) and it purrs like a kitten now.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 43
From: Auburn MA
Put it on the reader and its the O2 sensor on the left bank is basicly Inop it is reading lean so the motor is dumping in fuel to overcompensate and its killing my Gas mileage. I went from averaging 19-20 mpg to 12.8. But i am so happy its only an O2 sensor i thought for a second it was the Opti.... man did i dodge the bullet on that one.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Yes, I would say you are very lucky. So the SES light wan't on but the code reader pulled a code for the O2 sensor?? My 95 vette was running rough after it warmed up and idled rough, and had black smoke coming from the left muffler. My SES light wasn't on, so I had someone run a diagnostic scan on it and turned up the left front sensor was lean. I replaced the O2 sensor and it ran like a champ. From the description you gave it sound like a bad O2 sensor. While you under there check the wiring out for any shorts on the exhaust. Good luck bro.