Unlimited Revs with Weber 32ADFA

[Johnf]

1976 Spider 1800 with a 32ADFA. Running up through the gears, when clutch is depressed the engine does not come back to idle, but it runs wild without any throttle input by me. It has a water choke. The throttle cable is free and the whole mechanism does not get hung up. I'll take any and all advice.

John Frawley

[wetminkey]

I'm not completely familiar with the ADFA, but I'm sure that it has a fast idle adjustment,...is yours' incorrectly set? Should run fast on cold startup (1500 - 1800 rpm), and decrease (in steps) to normal as the engine warms,...
This may help you:
https://www.piercemanifolds.com/category_s/229.htm

[bobplyler]

I don't know about that carb, but on my 79 there's a throttle return spring on the linkage. Also, my original carb had a problem with idling too fast. No matter what I did, I couldn't get the idle down. I replaced the carb. And got much better performance, as well as an idle.

[18Fiatsandcounting]

Good suggestions so far. One other possibility is that the carb's throttle shaft is binding and so it doesn't return to idle. Try disconnecting the throttle linkage while the car is running, and move the primary throttle shaft by hand to see if you can tell if and where it's binding.

-Bryan

[blazingspider]

Check the return spring for the secondary throttle plate. I had one break and the secondary throttle would not return to the closed position