Sometimes when its hot out and I use the ac my car won't restart. It will start ok and then I will stop somewhere and it won't restart. It will turn over. The electric is fine. The engine temperature is normal. Sometimes it will star and the engine will rumble with vibrations and then die. I have only ever had this problem on hot days. If I leave it alone for a few hours and try again when the sun goes down it will restart no problem. My mechanic has done some testing and can't figure it out. They would like to see the car when it won't start but its very difficult to get it to them in time.