Slight correction to Shane280Z posting.
With key to ON, the fuel pump should NOT run. Period. Check the FSM, there is a table that explains this. To do the test he suggests, try this instead.
Use a jar, not a rag, and put the return hose into the jar. Unplug the wire to the starter solenoid. The starter will not turn now. Now turn your key to START. This will engage your fuel pump, without turning over the engine. Note, with no vacuum applied to the fuel pressure regulator, I'm not too sure how much fuel you will see coming back from the rail. Maybe plenty, since it is designed to prevent overpressure as well as underpressure. Just not sure.