Measure the clearance between the lever roller and the top of the fast idle cam using a feeler gauge. You cannot adjust the idle mixture if the idle speed is too fast.
How To Adjust The Choke And Fast Idle On Holley Carburetors
Fast idle cam adjustment. Turn the screw counter clockwise 14 of a turn. You do not want to aggressively throttle the engine to get the fast idle to drop. Set the idle to specification. If the accelerator is moved slightly open the fast idle cam will drop a notch and move toward curb warm idle rpm. Start the engine and let it warm to operating temperature or do the repair after a few errands that you needed to run anyway. Holley set up and adjust step by step duration.
Fast idle and choke has to be set with the engine cold so it can be a bit of a pain to get it right since you pretty well have let it cool completely off between adjustments. Now screw it in another 14 turn. Turn the screw clockwise 14 of a turn at a time until the rpm starts to drop. Adjust by switching between each screw. High speed idle cam discussion duration. Screw it in until it just touches the very bottom of the stepped cam not on any of the steps themselves.
How to adjust the choke and fast idle on holley carburetors holleyperformance. Then rotate it back slowly until the choke plate just comes closed. Slightly crack the throttle open unload the fast idle cam and turn the choke cap clockwise until you see the choke plate open. To get to the fast idle screw you have to open the throttle all the way and only then will you see it swing into view and be accessible. Back it off about one turn. At that point you can go ahead and snug those screws back up and thats going to give you a good starting point to make adjustments from.
If necessary adjust the fast idle cam screw a until the alignment mark is centered on the lever roller. As the engine warms up the choke spring tension will be reduced. Make sure that the choke is fully open and the fast idle adjuster screw is resting on the very bottom of the stepped cam. Unscrew the fast idle adjuster screw until it is clear of the stepped cam.
Gallery of Fast Idle Cam Adjustment
