[wiswind]

There is a fuel pressure test point on the front fuel rail....middle of the rail.
It looks like a tire valve.
One problem that comes up is that the fuel pump can fail, just as you describe.
Of course, I would try the fuel filter first.......as that will reduce the back pressure that the fuel pump is pumping against.

The other thing to check is the "Inertia" switch.
This is a safety switch that will disable power to the fuel pump in the event of an accident.
They can become intermittent.
The inertia switch is located in the jack compartment in back.....it is below the jack....should have a label on it.
You push the button to "reset" it.
The switch contacts could be corroded or even the wire connectors where the plug into the switch.

That is 2 things to check before the expense an LABOR of a new fuel pump, which is located inside the fuel tank.....you have to remove the fuel tank from the vehicle to access the fuel pump.

I do not know for sure......if they went to a fuel pump relay in the relay box in the engine compartment?
My '96 still had the fuel pump relay inside the "Constant Current Relay Module" (CCRM).
If you have the separate relay....that would be something that I would check/replace also.
Because the problem comes and goes.......it will be hard to troubleshoot.