My 1987 944s will not start, I have fire to the plugs, fuel to the rail, adjusted speed sensor, checked connector, but still no start. I can spray fuel into air intake and it will run fine as long as fuel is sprayed. I connected a noid light on the injector connectors and only got it to pulse when all 4 was disconnected, if I connect one injector, they all go positive, meaning that I have voltage on both wires on the connectors. This is driving me crazy. Please help
Thanks

 

Sounds like a possible bad fuel pressure regulator. Is the pressure spikes too high, the injectors will not fire.

 

Thanks, can this be tested? I will get back as soon as I can check this out.

 

Sure, put a fuel pressure gauge on the port on the fuel rail and check your fuel pressure during cranking and running.

 

I removed the wiring harness, reinstalled and she fired up. Thanks for all the good information. So until next time, have a good one.