Have an 1989 Ford F-150 with the 300 six and fuel injection. The problem is eletrical current to the high pressue pump. When I turn the ignition on the I hear the high pressure pump charge up, the truck starts no problem, when the ignition is turn on and the pump does not charge up then of course the truck does not start. But you never know when this will happen. I have replaced the fuse link in the system, replaced the high pressure pump and the fuel pump relay. Looking at the wiring diagram the only thing left is the EEC relay and the ignition switch itself, has anyone else had this problem?

 

I am no expert but ign switches are not expensive and easy to replace (on the steering column under the instrument cluster). However I would have a close look at the connectors at the relay, they can go bad.