OK so I have a weird issue going on. I have a 1988 ford f250 with a 1989 460. We just put the new motor in and after having to install a push button starter do to ignition issues I can't hear the fuel pumps come on when key is on. And no pressure in infectors.

Now here's where it gets weird. If I test the fuel pump relay with a grounded test lite fuel pumps come on and injectors build pressure. But after I remove the lite and start the truck it won't turn over and fuel pressure and pumps are off. We tried replacing cam shaft sensor and relay as well as ignition module and starter silanoid. Still nothing.

If I put a throttle injector test lite plug on one of the injectors and start the truck I get no lite. It does try to fire with starting flued but that's the only thing getting the truck to fire.

I'm sooooo lost please any help is appreciated. I don't have the time or money to just keep trouble shooting it and buying new parts that don't solve the issues. I kinda though maybe its a ground issue so I ran a ground directly to the fuel relay. Key on fuel is on key off fuel is off. Key on with ground and fuel on I get no fire of any kind.

 

Check the inertia switch under dash that cuts off fuel in the event of crash.

 

+1 on that.

If not that, you should check the ground to your PCM. The injectors complete the circuit with this ground, and have +voltage when the key is on. I assume if you checked the relays, that you checked the fuses first?

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