My truck died. I've replaced the fuel pump relay and EEC relay, thinking that was the problem, but it wasn't. I have spark, and the inertia switch is good. I bypassed the fuel pump relay for power to the pump,and it still won't start. I don't know what else I can do, any suggestions would be great
thanks, Sean

chekc your fuel pressure, just push the release with the key on.

The problem is that there is no power to the fuel pump.

So give it power.

Year?

truck is a f-250 1986.

Check the wire harness connector (1" square about) under the master cylinder. It is VERY common for the connectors to corrode and fail there. Also, the connector under the driver's seat on the inside of the left frame, check that for power as well. From there it is straight to the in-tank and frame (main) pumps.

I am also having a fuel problem with a 86 f250 no fuel pressure with key on or cranking over but if i prime carb to start then fuel starts pumping i dont know if there is a safety on this model that only lets pump run if oil pressure is present some cars will only pump for about one second to prime system then will pump normal after engine starts

I finally fixed the problem. A bad ground going to the EEC, which was disallowing the relays to kick over with a low 10.5 volts. Jumped the EEC ground to a good source and the pig fired up!