Good Morning. Last year Quadrajet carburetor leaked due to stuck float. Removed carb, took it to local gentleman who rebuilt it for me. Had good reputation from Car club members word.
Reinstalled in car. Car ran good, but took it out on road, immediately noticed that when taking foot off gas pedal, car idle was high around 1100 rpm. The carburetor was not returning to idle, I would tap the pedal and sometimes it would return to idle, but always. Very dangerous situation on the road as this is a very powerful engine. So, I was shifting to neutral when needed. Got car home safely.

Checked return spring in linkage. Tried adding a newer spring. Same result, reinstalled original return spring. Still intermittently won't fully return to idle.

I sense something in the carburetor is binding up, or the linkage itself , or a bearing in the carburetor itself affecting the free movement of the parts in the Carburetor, the opening and closing of the throttle. I in no way blame the gentlemen who worked on it. He was elderly. He ran it on a test engine after rebuilding it and it ran fine. It looked like new when I picked it up. When you repair an old part no guarantee.

At this point the answer possibly is a $600 new Quadrajet carburetor. I am terrified to drive this car now, particularly in any traffic, I don't want to hurt anyone.

I could take it back and have him look at it again. I am tempted to sell the car to a more experienced owner with this issue being disclosed.
Years ago my son's financial planner when hearing of this car hobby said "You are no Jay Leno!" I have three Oldsmobiles and being closer to retirement I am not going be able keep spending $ to keep them running properly. But I am willing to consider a solution to get it right. My first thought I just spend $600 and put on a new carburetor, second thought, take it to an experienced repair shop on a flatbed, but who??

Any ideas or thoughts would be greatly appreciated.

Thank you!

Jon Mueller

 

There are several ways for the idle to be stuck too high, none of them severe enough to warrant selling the car. When you reinstalled the carb, did you properly adjust curb idle speed per the Chassis Service Manual directions? It is not possible to do this without having the carb on the engine and warmed up. Ghat goes for a new carb also. Did you adjust the idle mixture screws? Did you adjust the fast idle setting? Is the choke fully opening and the fast idle cam being properly retracted? Is all linkage clear of wires and hoses that might be hanging it up? Is the gasket between the throttle body and fuel bowl correctly clear of the throttle bore (I had one case where an improperly cut gasket projected into the throttle bore and caused the throttle plates to hang up - but that is a low likelihood event).

 

Does your car have a rod throttle linkage or a cable linkage? A bad motor mount could cause a rod throttle linkage to bind, as the engine would rock causing a possible binding of the linkage! They started using cable linkage in the I believe late 60’s to prevent this from happening. Just one more thing to check.

 

You are correct about the change to cable linkages, but the Toro doesn't have this problem. There is no driveshaft to the rear axle that the engine reacts against when the motor mount is broken. Plus, Toro drivetrains mount completely differently from those in RWD cars.

 

Thanks for taking me to school Joe! Never too old to learn. lol