Mike,

If the needle and seat is somehow stuck shut it will not allow the fuel pump to transfer fuel. This would be rare though.

My thought would be the check valves inside the fuel pump are stuck from sitting so long. Working, wiggling and tapping on the pump might break them free.

I bought a truck that sat for 8 years, and after the preliminaries, it started right up. The pumps are made to bathe in gasoline.

Stuart