ok I'm having a really strange problem with the Idle when I start the car and it gets warm it mat or my not come down when I take the air filter off and filter housing exposing the carb and I start it and it Idles it warms up and drops down to like 900 but this is was really gets me some times when I have the air filter and all on it warms up and runs fine then when I give it some gas it just sticks idleing high but it I rev it to like 4-5k it drops down to like 1200 and I'm just lost on this

 

Dirt/grime around the throttle plate may be causing it to stick open slightly. Check all the throttle linkage for dirt/grime. Clean and lubricate.

Check the choke linkage to be sure it's not causing throttle plate misposition or binding.

good luck