The car is not starting.

The customer towed the vehicle in with a broken glow plug to be extracted. When further questioned, the customer acknowledged that he had previously overfilled the fuel tank, which overflowed. Since then, he said he could tow start it, but it wouldn't start using the ignition key. The glow plugs were replaced but the engine still won't start. The engine will crank for a few seconds, stop, then crank again and will not start.