My 1990 740 GL stalled and wouldnt restart. It has been taking a few cranks to start and then it just wouldnt restart. It will start with Carb cleaner in the throttle body, but runs really roughly and still stalls.

It has started twice, but the only thing we did was touch the TP sensor and it checks out fine. There is pulse to the injectors and they work during the self diagnostic. The self diagnostic shows nothing wrong. You can hear the fuel pump starting when the key is on.We have fuel to the fuel rail and spark at the spark plugs, but no fuel on the plugs. The injectors look fine, but what are the chances of all 4 going bad at the same time not letting any fuel at all to the plugs.

Two fuses had been melted into the fuse box and after rewiring them # 11 (which runs the fuel pump) blew once, but has been fine since. We traced most of the wiring to that fuse and it doesnt look corroded. We replaced the crankshaft sensor as the old one had more resistance than a new one, but no difference. The ECU's look good, no corrosion, but we dont have a tester for that and that wouldn't be intermittent anyway right? the fuel relay warms up when we did get it started.

Could the fuel pump be wearing down and demanding more power and screwing with the wiring? What does the PSI need to be at the fuel rail and is there a way to check that? Could the pump be running and generating pressure, but not enough to get the fuel atomized at the injectors? How do I know if I have one pump or two?

Thanks for your time,

Sarah