I have a quadrajet on my cadillac 500. The car runs amazing down the road. I recently got the carb running great with some different jet combos. It always was really rich before that. My new issue is recently the car has developed a issue when it first starts. It fires right up but quickly goes very lean 18.1-21.6 when under choke does not change with choke adjustment. Once it warms up or once I pop off the choke the AFR is dead at 12.6-13.2 all day. The other issue is the idle is erratic. I will get it to hold a nice steady idle of 650-700 for a few days no issue. Next time I drive it the car is struggling to stay running. The idle is now 390-400. I have to turn idle screw in a couple full turns to bring it back up. Then later that day or a next drive the idle is way to high. I did lower my float last time I had the carb apart to .420. Other than the idle and cold start issues the car runs amazingly. I am going to go home and check for a vacuum leak and also check my dizzy advance to make sure it isn't acting up. The dizzy is brand new though So I doubt it. Thanks for any help or input.
