So my 72 cutlass stalled out on me and would not fire back up had to get towed home. It's getting fire, clean fuel filter and the fuel pump is working. The carburatetor was dripping fuel under the choke so I removed the carburetor replaced seals fires up wow now it has a high idle.
Played with the idle screws,put a new spring on the throttle and adjusted air and fuel screws. When it fired up it was like the pedal was on the floor really high idle. Today I adjusted the choke and the idle is much better but it idles at 1500rpm then it will go to 2000rpm just keeps doing it up and down.
It's a quadrajet 4bb it was rebuilt a year ago and he had the air and fuel screws turned out 11 times and it ran good. The idle problem became an issue when I removed the carb. The metering rods that go into the jets looked good and I made sure they spring up and down correctly.

 

Make sure your choke linkage is correct and not binding. Also make sure the choke is completely disengaging when the engine is warmed.

 

As mentioned, make sure the choke is all the way open, and fast idle cam is disengaged. Also check for vacuum leaks. If wrong base gasket was used, you may have a leak.

 

Thank you guys the choke is disengaging correctly,no vacuum leaks as I was spraying the carb with carb cleaner all around it as it was running and no change with the idle.
I removed the carb checked things out and the base plate is correct. Something to do with the choke piece leakage that needs to be on the edge of choke valve and wall of air horn which controlls the primarys to close all the way. So I will put the carb back on today.

 

Did you check the intake at the heads?
Railguy

 

I don't know anything about quadrajets but my holley manual chock has a fast idea adjustment . Maybe yours dose too . Good time to look if the carb is off. Maybe someone will see this and tell you if so.
Railguy