Hi guys,

Quick question:
Is the "Fast Idle" setting on a Holley DP only for when the choke is closed?

Longer question:
I recently aquired my first holley 750 DP with a manual choke. I started a basic rebuild and took apart the choke assembly to inspect the diaphram in the vacuum secondary housing. I'm pretty sure I put it back together correctly (but not positive), as it appears the Fast Idle adjustment screw is supposed to ride along a cam in the choke mechanism. The screw isn't really making contact with the cam unless I close the choke all the way. The linkage is hooked to the axle of the primary throttle blades and my main idle screw is presently keeping it backed-off the choke cam when it is wide-open. Does this sound like the way it is supposed to work? Is this adjustments only to throttle-up while the choke butterflys are closed?
The chevy manual has a spec for fast idle (2400 RPM I believe) which seems too high for anything else but warming your engine.
I haven't had to use my choke (it's usually pretty warm here and I just feather the gas for a minute or so until it idles on it's own).

Do I need to be concerned about this setting if I never use the choke?

Thanks,
dan

The fast idle screw is supposed to ride on the stepped cam on the choke, so that when the choke is closed, the throttle plates are opened enough to get air for the amount of fuel the choke is causing to be pulled in.

As the choke opens, the cam should move so that the fast idle screw moves to a lower setting, and when the choke is all the way open it has no contact, and the curb idle adjustment is in effect.

The curb idle should not touch when the choke is closed, as the fast idle screw should be keeping the primary blades open more than the curb idle screw.

Thanks Ron for the thorough explanation.
This confirms what I was thinking.