Kodiaks 53 / S10 Build

[Kodiaks53]

Ran into a bit of a problem today which I haven't had time to look into just yet. I hooked up the fuel line from my electric fuel pump to the carb this afternoon and applied power.....fuel pump runs (external Holley unit for carbs) fuel pressure goes to 9psi them slowly drops to 0 . It never pumps up again, but the fuel pump runs. I'm thinking trash somewhere in the fuel system? Any suggestions? Where to start looking for trash? I did clean out the tank while off the chassis, put in a new fuel pickup, old one was useless, no fuel pump in tank its now a Holley external unit.
Any thoughts or suggestions?