Wierd Carb Problem

[petryshyn]

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.

 

[ak bandit]

Have you adjusted the timing at all? Sounds like you're timing is too advanced. Could also be why it seemed like your other carb was dieseling. Also check to make sure ALL your vacuum lines are connected. A buddy of mine spent 2 weeks scratching his head because he had 1 vacuum line causing a rought idle. But he was 100% POSITIVE that everything was connected....Until he saw a open hose laying behind his carb

 

[stockk5]

this is coming from dirt bike experience....maybe your float/needle?

 

[petryshyn]

Yeah timing should not be far off, I am also fairly sure that all the vacumn lines are hooked up cause I had it idling, just when i hit the throttle it was staying at 1500 rpm

 

[diesel4me]

might need a spacer...

Q-jet on an Edelbrock manifold might need a spacer or adapter for it to sit properly or seal 100% of the way to the intake...those huge secondary butterflies might be hitting the intake enough to prevent them from closing all the way too..

Could be the throttle cable bracket is a bit too far away for it to let it go all the way back to idle too..make sure the cable does not run out of slack before the carb is at idle..this is common when swapping carbs and intakes around..and be sure the fast idle cam on the choke is on the lowest step too..good luck..