John I had one where the accelerator pump linkage would hang up. I fixed it by reversing the S looking clamp that inserts in the accelerator pump and arm. Easy to check just take off the pump squirt and see if it goes away.

Took forever to find it. You could run the throttle by hand and everything was fine but the minute you drove it it would stick. Rev it and it would go back to idle. push throttle and stuck again.

This was on a two four barrel hemi with chokes removed and only one carb was sticking.

Mike