Help.....High RPM's after WOT

[struck by Lightning]

Any suggestions and help is appreciated:

After WOT the RPM's will not come down?

1. I have added a ground wire to the carbs choke
2. Adjusted the float levels, they were slightly below sight glass center line
3. Checked for vacuum leaks, going to change the carb gasket just in case
4. Readjusted the idle mixture screws to achieve max vacuum
5. lowered the idle screw

Car idles and runs great at cruising speeds, no hesitation or surging.

Quickfuel SS-780-VS Carb
Automatic transmission

Any ideas guys?

[71RS/SS396]

Have you looked at the distributor? Maybe the advance weights are sticking but I would think it would happen at part throttle as well. If the distributor checks out ok you have to be drawing air in somewhere, bad brake booster, trans modulator or line, vacuum line, bad pcv valve, sticking throttle linkage...etc.

[struck by Lightning]

Have you looked at the distributor? Maybe the advance weights are sticking but I would think it would happen at part throttle as well. If the distributor checks out ok you have to be drawing air in somewhere, bad brake booster, trans modulator or line, vacuum line, bad pcv valve, sticking throttle linkage...etc.

Tim - thank you for responding.

I checked everything and pulled the carb to replace the gasket with no luck. I decided to bolt up a Proform 750 mechanical secondary carb that I had and that did the trick. I believe the problem may be a faulty electric choke but will tear into it later. For now, I'll run the Proform carb at optima this weekend.

[dirty rick]

Secondary butterfly probably not closing fully.