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Old 05-10-2012, 10:12 PM
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Holley Carb Fast Idle Adjustment

I have installed a newly rebuilt Holley 600 CFM 80457S carb with electric choke on my Small Block Chevy.

Carb runs really well but had to make the usual adjustments, curb idle, etc,.

I'm trying to adjust the choke and fast idle but having difficulty.

Normal startup routine:
When cold, I pump accelerator once for an initial shot of gas through accelerator pump. Then, without touching the pedal, I crank the engine..and it fires and revs at 1800 RPMS...This is a bit I give the accelerator another small pump...and insteading of the idle droping in a graduated steps, the engine RPM immediately drops below 1000 and eventually it stall because it is not warm enough.

My undertsanding is that as the car warms up and the choke slowly releases the Holley carb steps down the fast idle cam in graduated increments. Once fully warm it it reaches curb idle.

Is what I am experience normal? If not what am I doing wrong?
Manual says to adjust fast idle to about 1200-1500 RPM? But which step? the first one? There are five steps in Holley fast idle cam. BTW, the choke is set at it's middle lean/rich setting.

Once the engine is fully warmed, the Holley is solid and runs like a champ. But until 100% warm, I stall at least 2 times before I leave the driveway...a bit aggrevating)

Help and guidance would be appreciated. Thanks!

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