Jim Grant's Tech Tips
Chevy Truck, Sticking Accelerator
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?
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.