Rough idle when warm?

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Oct 31, 2006 | 12:28 AM

Justin1889

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From: Waco Tx

Rough idle when warm?

I purchased a 99 FRC a couple months ago and lately have noticed when it gets warm it has a very noticable shake at idle. Last weekend I put in new TR 55's and MSD wires and had a friend hook up his scan tool and everything look good. Does anyone have any idea what could be causing this? BTW the car has 47k miles on it.

Oct 31, 2006 | 01:00 AM

Bill Dearborn

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Depends on how much shake you have. They all have a little lope at idle. Is this something that just started or has it been there all along and you just noticed it?
Bill

Oct 31, 2006 | 05:40 PM

jasonlu

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Clean All Of The Carbon Out Of The Throttle Body.

Oct 31, 2006 | 08:52 PM

JR_VETTE

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Quote:

Originally Posted by Bill Dearborn

Depends on how much shake you have. They all have a little lope at idle. Is this something that just started or has it been there all along and you just noticed it?
Bill

Oct 31, 2006 | 10:36 PM

Justin1889

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From: Waco Tx

Quote:

Originally Posted by Bill Dearborn

Depends on how much shake you have. They all have a little lope at idle. Is this something that just started or has it been there all along and you just noticed it?
Bill

I don't recall it doing it when I first purchased it 3 months ago, atleast not the extent that it is shaking now. This is quite a bit more than a lope....you can see the motor moving when it misses or stumbles. I took it to a friend of mine who is a GM tech that does alot of high performance work on the side. He hooked it up to his scanner and said that everything looked fine and wasn't showing any misses.

Oct 31, 2006 | 10:40 PM

NW_Vettes

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From: Albany Oregon

Clean your MAF with a MAF cleaning spray. This tends to be the culprit behind these sort of things so start here

Nov 1, 2006 | 08:14 AM

Linxs

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From: Katy Tx

I have the same issue. I've changed the plugs/wires, O2's, seafoamed it, put fuel injection cleaner in the gas tank, cleaned the TB. I have not had a chance to put on another MAF yet (I have an SLP MAF sitting in the garage). Nothing looks out of place when I scan it either. Another board member suggested "Use a timing light to check the coils. We have found the coils can be bad/misfiring and still not throw codes... I had that problem for 8 months and finally fixed it with a coil replacement.
"