I have a 1990 911 Carrera 4 that has just had a complete engine rebuild and have stalling issues:this occurs; in traffic or at a stop/red light when I take the car out of gear and step on the break the idle drops so low all the dash red lights come on and the engine dies out. I restart it right away. And the idle picks up to normal. Once in awhile all the red lights come on but it come back to life and the engine returns to normal idle. can anyone guide me on what I should do?