I just finished swapping carbs because the one I rebuilt was having a dieseling problem, and a wierd idle problem. I swapped on a rebuilt carb I got a while back which I intended to run, (quadrajet). The problem is the idle is staying at 1500rpm, the return springs are good, the throttle cable seems to be good, but here is the wierd part, when the carb is off the edelbrock intake it seems to shut just fine against the idle screw, but when on the intake it doesn't want to shut completly and stays a couple tenths of a cm away. Could there be interferance between the gasket and the plates somehow, or the metal, or give me some more info on why the throttle doesn't want to shut completly. Thanks, this problem almost makes me want to swap to fuel injection. If this doesn't make sense post up and I will try to clarify myself clearer, makes sense in my head.