Truck Repair: fuel, gmc pickup, throttle plate

Question
1996 GMC pickup 5.7 truck has ran very well then
would not start the other day. checked and installed new fuel pump and filter now getting
fuel to the throttle plate but will not start
added fuel down throttle plate and truck will start. theres a big plug behind the throttle
plate where the fuel lines enter does this meter the fuel and could this be the problem

Answer
Hi Rick,
If you see fuel entering the throttle plate, and it won't even hit on it, is there a chance it might be water? Like from a gas can?
I assume it is fuel injected, with an in tank pump? If so, there is no filter at that plug, but there is a pressure regulator that maintains 13PSI when running.

If yours happens to have a carburetor, then there is a filter behind that big nut.

Van