95' Rough Idling
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1st Gear
Joined: Apr 2005
Posts: 1
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95' Rough Idling
I got a 95 corvette of course with the LT1 which likes to idle rough when the engine is over 200 degrees or right before the fans come on. I so far put a manual fan switch in it to turn the fans on earlier. Though even with this problem the engine still runs fine when moving and shows no loss of power. Anyone have a good explanation of what the problem may be? My only idea is maybe it needs a new distibuter but as you probobly know the opti-spark isen't exactly a cheap simple fix. THe vette has 108,000 miles on it. I know what your thinking I beat it to crap.Your wrong. I bought it 2 years ago with 105,000 miles on it off an older guy that was the original owner and he used it as his everyday car. Since he really didn't appricate vettes for what they are he never beat it up and always had it professionally repaired. So all in all the car looks like it has 20,000 miles on it. So now I do what everyother Corvette owners does, park it in the garage under a cover and brag about how fast it is.
Last edited by snow rider; Apr 2, 2005 at 09:16 PM.
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Joined: Jul 2003
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Well don't assume the worst and throw the big money at it first. It doesn't sound like an opti but I never say never in this business. You don't state how many miles are on it but I'd start with a good throttle body cleaning, replacing the PCV valve with an AC Delco piece and check your basic ignition components such as plugs, wires. Could be an IAC getting weak, you get the idea. I'm sure you'll get some other good ideas and easy things to check.
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
you say that it idles rough at 200F , so I am assuming that it idles OK during engine warmup. Sounds like your idle is messing up when the PCM goes into "closed" loop mode. Sounds like you have a an O2 sensor(s) which has gone bad. O2 sensor feedback only occurs during "closed" loop operation. I also have a '95 , and I had the exact same Idle symptom as you, it idled fine for the first 10 minutes of driving, then idle'd crappy when engine reached normal operating temp. It turned out to be a bad O2 sensor on drivers side.
When your engine is "cold", the PCM is running "Open" loop, and the O2 sensors are ignored.
READ YOUR ERROR CODES FIRST:
You can short pin 4 and pin 12 on your ALDL and read the error codes from the LCD screen which normally displays Fuel level. Chime in if you need more info. on how to do this......
When your engine is "cold", the PCM is running "Open" loop, and the O2 sensors are ignored.
READ YOUR ERROR CODES FIRST:
You can short pin 4 and pin 12 on your ALDL and read the error codes from the LCD screen which normally displays Fuel level. Chime in if you need more info. on how to do this......
Last edited by MikeC4; Apr 2, 2005 at 11:36 PM.
