I bought 1984 Porsche 944 couple of months ago. Have been working on it to get it to run. Initially it does start and run, but it cuts of. I changed the fuel pressure regulator, battery, and mass air flow sensor. After that the car stopped even running. It does crank but doesn't start. I have checked the timing, but it's not off.

I got it finally to run after working for a long time. There is fuel and spark. I took off the serpentine belt and power steering belt. Now it does start and will run forever without the serpentine belt, but can't move it because the alternator is not connected so the battery will die soon. I also noticed that it is overheating and smoking a lot so I changed the oil, coolant, and put new gasoline and it stopped smoking, but still overheating.

When I put the serpentine belt back on, the engine is cranking and trying to start but it can't keep running for more than a second or two.

I don't know what connecting the serpentine belt has to do with the starting problem.

Any ideas?

Thanks,