Hi folks, I've got a quadrajet question that is on my 83' Z28. I have an odd idling issue. After the engine is warm and the choke is disengaged, my idle is running 900-1000 rpm which seems ok. When I go down the road and then push the clutch in, the idle sits at 1500 rpm for anywhere from 5-20 secs, then drops down to 1300 rpm for again 5-20 secs and finally resting around 900 rpm after that. And then, on occasion, the rpm will drop to 750 rpm (way too low). At the lowest rpm the engine starts to slightly stumble. Any clues as what would cause the carb to behave this way? Didn't know if anyone has had this issue with their quad? I'm brand new to the site so hopefully I can retrieve any answers

 

It has been a very long time since I have had any encounters with a Q-jet, so take this as a shot in the dark at best.

When I used to run them, they were known to have a fuel leak down issue in the float bowl. Nearly every rebuild kit came with a neoprene plug that was installed between the throttle plate and the carb body. If you haven't rebuilt your carb in a long time, I'd suggest picking up a rebuilt kit and freshening up the unit.

Good luck.