Weird idle problems...?

[89iroc-Z]

Sometimes when i start my car it runs at like 2500rpms. next time i start it. it will run at abou 1100. or i will start it and it will be 1100 then a lil while later 2500 again.
any help would be great thank you :D

[dwilliamsfaq]

Is it carb, TBI, TPI? if fuel injected sounds like the air temp sensor is choking the idle.