My car loses power while driving. All the lights on the dash board go on and it just dies. I have a new alternator, wire set, spark plugs, dist cap, tension belt, hoses. It doesn't over heat when stalling while driving. I have taken my car in 3 times in the last 4 months. It is back at the shop today. SO far they cannot find a problem. Engine strong, starts right up. After I managed to get the car in a near by parking lot I called my mechanic and started the car right up again and was able to drive in the parking lot. I had it towed rather then chance driving in heavy traffic. Frustrating because it other wise runs well. It is a 1993 Mercedes 300E. Sometimes it seems a little slow when accelarating but then speed kicks in. It is a heavy car with a 6cyl engine. Could it be the fuel pump? They are checking that tomorrow. Mechanic said engine and other main things seem fine. No strange burnt smell that would indicate electrical short. Sometimes though when starting car one of the head lights won't work then after minutes it goes on. Short somewhere where light is but stalls happen during daylight. Could a short without smell cause this problem while driving full speed (the losing power and car shutting down?)

Optional Information:
1993 Mercedes-Benz 3ooE 6 cyc

Already Tried:
alternator, wire set, tension belt, dist cap others/p>