Jim Grant's Tech Tips

’86 Chevy Truck, Sticking Accelerator

Q: I own an '86 Chevy Truck C-20 with a sticking accelerator. The truck has 280k miles on it. I suspect the bushings are worn on the carburetor butterfly plate. Is this an easy fix or do I send it to a repair shop?

Jim

A: The carburetor you’re referring to is likely GM’s well loved and hated Quadrajet. The wear problem with the Quadrajet carburetors was due to the steel throttle shaft wearing into the aluminum housing of the throttle body assembly. The throttle body assembly does not have replaceable bushings. To correctly repair this wear condition requires removing the throttle plates and shaft from the throttle body. Then the holes for the throttle shaft are bored out to allow for bushings to be installed and fitted to the throttle shaft. In some cases the shaft is too worn and has to be replaced as well. This type of work has to be done correctly or the throttle plates will bind when reassembled. You’ll need to find a machine shop or carburetor shop that performs this type of repair.