Dumb question - Engine Idle
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Launching!
Joined: Jan 2011
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From: Dickson, TN
Dumb question - Engine Idle Tried searching couldn't find. I have a 2000 Z28 A4. Idle in drive is about 650rpm according to the stock tach. Is this too low, and is there a way to raise the idle properly? Car runs and drives good. Just wondering.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
The stock tach is almost never 100% accurate. You will need a scanner if you want to confirm the true idle rpm.
Stock GM tuning for these cars results in the following commanded idle speeds:
A4 cars: 650rpm in park/neutral, 550rpm in gear
M6 cars: 800rpm
The above is true for all years of LS1 F-body.
Idle speed can be modified via custom tuning. As these engines have an IAC motor to maintain commanded idle speed as temp and load conditions change, there isn't much you can do to adjust idle speed without some negative side effects (other than the proper method, which is custom tuning to change the commanded idle in the PCM).
Stock GM tuning for these cars results in the following commanded idle speeds:
A4 cars: 650rpm in park/neutral, 550rpm in gear
M6 cars: 800rpm
The above is true for all years of LS1 F-body.
Idle speed can be modified via custom tuning. As these engines have an IAC motor to maintain commanded idle speed as temp and load conditions change, there isn't much you can do to adjust idle speed without some negative side effects (other than the proper method, which is custom tuning to change the commanded idle in the PCM).
Teching In
Joined: Apr 2010
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From: AL
there is a idle adjustment screw on throttle body. it is upside down, cant see it without mirror. takes a small torx bit, cant remember size. unsure about how it will affect stock tune though.
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Joined: Nov 2001
Posts: 34,647
Likes: 2,573
From: Schiller Park, ILL Member: #317
If you have a stock cam, there shouldn't be any need to adjust the idle speed.
