My 1993 626 4-Cylinder is driving me crazy. It won't stay running. It will start and run for an hour or two, then dies. After it sits and "cool's off" for about a half hour or more it will start back up and run for a short period of time. If I try to start it immediately after it dies, it won't start. There is gas flowing through the lines, the fuel pump, alternator, O2 sensor, distributor, and water pump are all brand new. The timing has also been reset. I've read the Haynes manual and checked everything I can think of. Can you please give me some ideas as to what the issue could possibly be?

 

It would be helpful to know if you are losing spark or fuel pressure when it dies. It depends what is going on as where to start looking.