Fuel Problems

1992 Ford F150 with 160K+ miles, 4.9L

I have to spray gas in the throttle body to crank it and keep it running. I hear the fuel pump running when I turn on the ignition and it never stops, like it's not building up pressure. I have replaced the fuel pump, fuel filter, fuel pressure regulator, cleaned the tank and swapped out the relay with one of the other in the fuse box. Fuel seems to be getting to the rail ok. There is a lot of gas released when I push the valve. Am I missing another component that helps supply fuel to the injectors? Can all the injectors be plugged or bad at once?

I have also replaced the spark plugs, wires, distributor cap and rotor cap, so those are ok.