93, GMC Van won't start

well I have been trying to get the thing started and stay running.

Heres what's wrong now i changed the fuel pump cause I was getting 10 psi the it dropped to 3 psi now i get no pressure at all but i get gas to tbi and i noticed that when i did a volt check i get battery voltage the it drops to zero in about a minute

So let me run this by you, let me know if it's accurate:

You have a '93 GMC with an electric fuel pump and throttle body fuel injection. Initially you had low (10psi) pressure at the throttle body which quickly dropped to 3 psi.

You changed the fuel pump and now you have no fuel pressure at the throttle body. There is voltage to the fuel pump for the first several seconds while it attempts to prime the system.

I'm lost by your comment of no fuel pressure but there is gas at the throttle body. Where are you measuring the fuel pressure? Did you change the fuel filter when changing the fuel pump?

If you spray throttle body cleaner into the throttle body while someone else cranks the engine, eill it start and run while cleaner is metered in?

-Rod