the onlt other thing i can think of with idling when the engine is warm, is that it could be the Fast Idle Thermo Valve. It is located below the air intake connection and is held on with three bolts. Also make sure that your coolant level is high and bleed any air out of the coolant lines using the bleed valve. The fast idle control valve needs coolant to work properly because they depend on the coolant temp.

 

It is looking bad in that case, i've fixed the FITV time after time, TB with it, blah blah blah... Coolant was recently changed as well as air bubbles...

 

try something simple like adjusting your idle...set screw on throttle body. could be ecu....get another one....other then that i am out of ideas....anyone else? maybe this would shed more light....when did this start idling like you have explined......overnight or afer an install......or evr since youowned the car? etc... no codes right?

 

No codes, idles as- is since i've owned the car, idle screw is all the way in and no help, have an Si ECU that I have tried just to see how she idled, no help in doing this.