1990 e 350 wont run

Before i crush this thing and trade it in on a truck i can work on, i will try one more time to fixx it.I have a 1990 e 350 with a 460 in it that will run only when you pour fuel in the throttle body when it runs out it stalls. i have changed to many parts to list and yes it has fuel in the tank i think the injectors are not firing and without a NASA tech helping me not even the ford dealer has been able to help me. any advice please thank you

Ok, so it does run on gasoline but not by itself.

This means:

1) The engine is ok
2) The computer is working, at least enough to make spark
3) The spark plugs, wires, etc are all functioning ok.

You have a fuel problem.

What is your fuel pressure with the key "ON", as you try to start it. It should be about 40 PSI.

One of the most common causes of this is low power (voltage) to the fuel pump(s) caused by a bad fuel pump relay or corroded connections between the relay and the pump(s).

Find the fuel pump relay in the "Underhood fuse and relay box", remove the relay and short the two LARGER terminals with a wire. You should HEAR the fuel pump(s) running. If you do, check the pressure at the fuel rail with an appropriate gauge (buy or rent from local auto parts store). If pressure is good, there is a problem in the injector wiring. I suspect that you will have low fuel pressure, if any at all. If the pump(s) run, but have low pressure I would look at the fuel presure regulator as a (very) likely cause.