So I had a few a issues with my quadrajet (1985 firebird) including dieseling when shutting down, harder than normal start when cold, and throttle sticking open after going wide open throttle. I would park and the engine would rev to about 2000 rpm, and I would physically have to grab the throttle linkage and pull it closed, after that it would fine until I go wide open again.

I figured it was time for a rebuild, solved all issues except for the sticking problem. Has anyone else had a similar problem? Does anyone know what could causing the linkages to stick? I don't see anything binding, it's as if the throttle spring is not pulling it closed hard enough.

 

Disconnect the throttle and TV cables from the carb. Does it still do it?

If not, then you've got a problem with one of the cables.

If it still does, then you've got an internal carb linkage issue, or something interfering with the throttle blades. Not uncommon for a carb gasket to get in the way and hold things up.

 

Worn throttle bushings?