I think maybe my oil pressure at speed is up around 55 or so but just idling with hot oil less than 40. I just sort of notice the general position of the dial and not exact numbers.
You first need to determine whether the 12 volt Ignition source (maybe from a 20 amp fuse) is being provided to your relay (and the oil pressure sending unit) when the key is on.
Just pop out the relay from its connector and check for 12 V on Pin A of the cable connector pins.
If you wanted to, you could then move down to the oil pressure sending unit. Same thing. Unplug the connector and look for 12 V on one of the 3 pins. But at this point that's not necessary until you get the engine started on the relay circuit.
Once you've established that you have Ignition voltage I'd then go back to the relay and jumper the 12 V on pin A over to pin E while somebody is back at the gas tank. Hopefully the pump will be running. If it is not running then the likely problem is either bad wiring back to the pump or the pump itself.
If the pump runs with that jumper installed but not when you plug the relay back in and turn the key on it comes down to perhaps the computer (Control Module - ECM) - - or a loose connection somewhere. It's not energizing the relay coil to switch the contacts to provide power back to the pump. That control voltage would appear on pin D for 2 seconds when you turn the key on.
You really don't care about that oil pressure sending unit at this point. Just whether you can get the pump to run off the relay for a couple seconds. That tells you the pump and pump wiring is ok. Then the engine should also start and run for a couple seconds (and if the oil pressure sending unit is ok it should keep running).
One tricky thing to be aware of when checking for voltage on high amp vehicle circuits is that a sensitive voltmeter could show 12 V since there is virtually no load on the circuit but with any load at all the voltage could go all to h*e*l*l. (Gotta keep the moderators happy.) A corroded connection or loose wire could make that happen. Sometimes a bulb type trouble shooting tester may be a more reliable indicator for voltage. It puts at least a little load on the circuit. Hope this gets you going without too much wasted time.
Have fun