1994 Chevy Lumina stalls at stops

My 1994 Chevy Lumina drives great when its in motion but when it warms up it will stall when your at a stop light. It does great at a quick stop,like a short red light or a stop sign but when Im sitting at a long red light it just stalls. It will start right back up but this is annoying. Recently the car radiator was replaced, so the car over heated. What could the problem be?

Chances are you have a leaking fuel pressure regulator. It is located close to the throttle body about two inches in diameter with a vacuum line going to it. Remove the vacuum line going to it and check for the presence of fuel.

The problem might be caused from a defective Idle Air Control or IAC valve or circuit.
This is what controls the engine idle speed whenever the accelerator is released.

You might try removing the IAC valve and clean it along with the idle air bleed port on the throttle body to see if this improves the idle condition. If not, more than likely there’s a problem IAC valve.