96, 2500, 305 won't start?

My van won't start I turn the key forward the pump kicks on it builds 62p.s.i. and then the pump shuts off like it is supposed to but then the pressure drops right to zero and there is no fuel for it to start.
Do I need a pump or is there a check valve that is bad somewhere it seems like the pump motor and sending unit work perfect but it just loses pressure.

Please HELP my van is driving me nuts!

Jumper the gray fuel pump wire with a fused jumper and take the pressure reading with fuel pump running.
You should have 64-65 with pump running.
Then plug off the return line for a few seconds and recheck pressure.
If the fuel pump is good the pressure should jump to 85 lbs or more with return line blocked .
Then check direct pressure at the in line at fuel filter.
See if pressure there jumps up to 75-85 and holds.

Fuel pressure can leak down at fuel regulator or back into the pump check valve or may have a line leaking.
For a final test on a fuel puump check running pressure on the road after a 15-20 minute run.

I checked everything out and when the van is running all the pressures seem right, at idle it has 55psi but I had a guy at the auto parts look up what it should have and the book said 50 to 66 is acceptable. The van is starting every time now but still cranks longer than it should which I am assuming is because it loses pressure after the fuel pump initially kicks on.

Should the pressure line stay pressurized after the fuel pump kicks on for the first time?
What would be the symptoms of a bad fuel press. regulator?

Your pressure is low.
Specs are 60/66 lbs of pressure.
You need 64-65 lbs for a cold start engine cranking pressure.
What did the full pressure come up to with return line blocked off?
MT