first off its a 305 tbi.


so when i start my car it jumps to 2,500 rpm. the person before me told me it was it warm it up. it goes down after sitting for a few minutes. if i put it in any gear it drops down. but still runs higher then 1000 rpm when idling. anyone know whats goin on? my uncle who knows more about cars then anyone else i know said there is a screw on the carb that you can adjust. i looked and saw a screw but it had no screw head on it..

 

Well, if its a 305 TPI then it doesn't have a carb. It is fuel injected with a throttle body. It common for the car to idle a little high when first started, mine does the same. And most likely all you have to do is adjust the idle screw, but someone correct me if i'm wrong, but the idle in park should be 900 to 1000, so your not the far off. But in gear it should idle at 6 to 750. the idle screw is on the side of the throttle body, its the screw that the throttle rests on.
Good Luck

 

my 86 doesnt idle that high but it has a carb so that could explain that

 

He doesn't have TPI, it's a TBI (fuel injection carb-looking unit).
When things are working as they should, you shouldn't have to fiddle with idle adjustments.
It's more than likely either the IAC-Idle Air Control motor (sticking out on the rear passenger side of the TBI), or a vacuum leak.

 

also check tps (throttle postion sensor) and iac (idle air control) like Camaro 69 and to check for vacuum leak spray carb clear wd40 etc. around base of tbi unit and manifold also vacuum lines idle will bounce around then if vacuum leak

 

or it could be the also very common faulty tach. 2500 is higher than what it would be with the brake booster vac line off