When i start my car it will not idle at all... I have to feather the gas to keep it running and im coding for the Idle Air Control Valve... anyone know how to correct this problem?? Plus Its a 2000 LS head on a 1990 Ls block so im pretty sure that the sensor isn't bad.

 

make sure the correct plug is plugged into it. The air intake sensor has the same plug and is very close to the EAVC.
Try to clean it out. Make sure there is no carbon build up on it.

Take your throttle body off and clean that too with some carbon cleaner. I had crappy idle until I did this.

 

Same here...open your book and trace the line...make sure the right hose goes where and wallah!