1998 Ford Explorer Fuel pump won't run

THe fuel pump will kick on for a split second when the key is turned on and that's it. I took it to the dealer and they said it had something in the fuel tank and it wouldn't let it build pressure but I dropped the tank and the gas is good and a new fuel pump does the same thing even before it was submersed in the gas. If I hook a hot lead to the fuel pump it will run and build 40 psi but it still won't start. This leads me to believe the injectors also aren't working. It will start and run off starting fluid. I checked all the fuses and the fuel pump relay and they are all good. I checked the cam position sensor and it seemed to be good but the book said one of the wires going to it should have 1.5 volts and neither had anything. The crank position sensor seemed to be good too. I also got a computer from the junkyard cause I thought maybe that was it but it still does the exact same thing with the different computer in it.