In addition to what Bob said, it also only takes a pinhole in a steel line, a cracked rubber line or even a loose clamp to make the fuel pump suck air instead of gasoline.Disconnect the line below the fuel filter to be sure that's not clogged.
Replacing the pump is easy, except access is not great. Disconnect the fuel lines in and out, and then the bolts holding it to the right side of the engine. When installing, be sure the pump arm is riding on top of the camshaft lobe and not under it. This would break the pump arm and possibly the camshaft. To avoid this, after installing the pump, turn the engine by hand and see if it binds at all.