Bought this car in a barn find kinda deal not running but all original great condition. Put a distributor, fuel pump, plugs and wires on it and got it running. It did good for a couple months until one morning I started it up and noticed the throttle was sticking. Jumped the gun and bought a Rochester quadrajet reman to put back on it. Put it on and it flooded my motor. Pulled it apart today and the needle wasn’t set in the float right, set it put it back on the car changed the oil and started it up idled great. As soon as I touch the gas it seems to hang, if I pat it hard it comes back down… same as the one I replaced. Pulled the throttle cable, kickdown, and return springs off of the carb and started it. It would idle for about 5 seconds then rapidly idle up until it sounded like it was going to tac out. Shut it off worked the throttle by hand and cranked it again same thing. I’m lost at this point.

 

Are you sure your return spring is not weak or stretched? I'm thinking if you took the return spring off, a weak or stretched spring would have the same effect.

 

I replaced the spring when the problem first started thinking that would be it. So far I have found a vacuum hose with a slit in it, one of the primary valves were bent, and I can’t for the life of me get the fuel leak where the line threads into the carb to stop. I swapped out the valve and replaced the vacuum line. Put the new carb on about an hour ago since I had a little time after work and it started at a high idle, I patted the gas, and it idled down. No sooner than it idled down I smelt gas and had a puddle on my manifold so shut it off without checking to see if it was still going to hang up. Letting gas dry up and will try again tomorrow. Thank you for response though

 

Good luck! Keep us up to date.