No fuel pressure in 96 silverado

I have 96 /chevy silverado 1500 pickup it started developing start problems; finally stopped and would not start again.
I assumed it was a gas problem because if I sprayed starting fluid in it would start right up.
So I have replaced the fuel pump, the filter, the relay and the pressure regulator. I can feel the relay relaying and hear the fuel pump energizing but (using gage) I have no fuel pressure.
Can any one help.

If the pump is running, either it's a bad pump, a line has come off in the tank, or there is a restriction in the fuel line. Was there any rust in the tank? Unhook the fuel filter an turn the key on to see in there is pressure to the filter. Just be careful!!!!

Thanks for the input; i did loosen the filter and there was no gas when cranking.
There also is little trash and no rust. I will remove again and check connections.