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Old Oct 23, 2007 | 09:30 PM
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Well just bought my first corvette. Its a 99 c5 with alot of aftermarket goodies!!! I have a small problem with the idle though. The car has a fairly large cam and is a bit lopey. But what I have noticed is that the idle will go from 1100 to 500 rpms and will keep on fluctuating. Warming up does not seem to help. Some times I can get the idle to stop fluctuating but as soon as I give it gas it dies. It runs fine after I am moving. any ideas? Thanks Steve
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Old Oct 23, 2007 | 09:32 PM
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Hmmm....sounds like an appointment with a tuner is in your future.
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Old Oct 23, 2007 | 11:10 PM
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Originally Posted by lucky131969
Hmmm....sounds like an appointment with a tuner is in your future.
Also look into raising your idle. Is it an A4 or MN6?
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Old Oct 24, 2007 | 02:44 AM
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You need idle tuning in your PCM. Unless you have software like HPTuner, you'll have to take it to a tuner who can adjust it for you. Your "Target Idle Speed", Base Running Airflow and Throttle Cracker parameters probably need to be tuned. This assumes you don't have any vacuum leaks in your intake, throtttle body, air bridge and MAF areas.
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Old Oct 24, 2007 | 06:17 AM
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Default bad idle

thanks for the replies, The guy I bought the car from said that it was tuned in may and Carolina auto masters was who tuned it. He said it was a $400.00 tune. I am still learning about these cars so what is a A4 or a MN6? Sorry I have had my Grand National for awhile now and need to get back into v8 mode. Will check for vacuum leaks first. Thanks Guys
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Old Oct 24, 2007 | 06:28 AM
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Originally Posted by robste
thanks for the replies, The guy I bought the car from said that it was tuned in may and Carolina auto masters was who tuned it. He said it was a $400.00 tune. I am still learning about these cars so what is a A4 or a MN6? Sorry I have had my Grand National for awhile now and need to get back into v8 mode. Will check for vacuum leaks first. Thanks Guys
A4 = Automatic Transmission
MN6 = Standard Transmission

I agree with the others. You appear to have either a tuning issue or a vacuum leak (or a combination of both) and the only way to definitively find out is to get with a good tuner. The PCM controls most everything on the engine including idle speed.

Welcome to the forum.
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