When my car is cold, when I start it the idle is around 2000 rpm's which is normal when cold, but it takes for ever for it to drop to normal (700rpm's)when the engine is warm (220+degrees). Thats a good 15 minutes for a high idle. It wasnt always like this. It used to take a few minutes to warm up enough for the idle to drop and it didn't need to be as warm. Any suggestions?

 

If this is a Rochester carb, you should check the choke heater element, it's power supply, and ground.

 

My carb dosent have a element, it never need it.

I think its involved with the Choke themostat or the pull-off, but I don't know. Another thing I forgot about but it may or may not be related to my problem is after I shut off my car after running up to normal temp when it was cold, it backfires once. If I started it again while its warm then shut it off it won't backfire anymore. Only after it was cold.

 

bump

 

I'd say you should check the choke heater element, it's power supply, and ground.

(The heater element is built into the choke thermostat - in fact, it is the same thing as the choke thermostat.)

 

So your QuadraJet doesn't have an integral choke, but a divorced choke heater? I thought those went out in the '70s.