2001 f150 supercrew wont start but will turn over low on fuel.

can you hear the fuel pump run when you turn the key to the run position(not start position)maybe nothing to do with theft light-cheers Denny

Give some more details of the problem.

Usually if no rpm signal, the vehicle won't start. Engine cranking, did you check for spark at the spark plugs? The fuel pressure you listed may have been the initial prime. It sounds like no injector pulse. The rpm signal comes from crank sensor. If your missing rpm signal, may thought is the crank sensor.
Were there any applicable trouble codes?

The gasoline in it is very likely no longer any good. Put new gas in with an additive designed to remove water and it should turn over.

When you turn the key forward you should be able to hear the pump turn on. Have someone listen by the gas tank.

When the crank no start happens, is the theft light blinking ? If you turn the key from the off to run position ( do not start ) does the theft light on the cluster go out ?

If not, check the key ring for other RFID fobs ( Mobil speed pass, etc ). If they are too close to the ign switch, this can mess up the RFID of the programmed key for PATS ( Passive AntiTheft System ).

If the theft light goes out, it could be a problem with the fuel pump relay. You can swap this with the trailer tow battery charge relay to test. My 2001 SuperCrew had the fuel pump relay go out at ~ 30K miles ( think that was it, it was low ).

If the relay change with the battery charge relay does not change things, is this happening with a specific fuel level ( i.e. 1/4 or 1/8 th of a tank ) ? Could be something floating in the tank that is getting pulled to the fuel pickup, blocking the fuel to the fuel pump.

The other thing , it could be the fuel pump itself, but start with the PATS check, and the fuel pump relay.

You can check to see if it is a fuel issue next time remove the air cleaner and shoot a squirt of carb cleaner in the throttle body if it fires right up with it running give it a little gas and squirt sperts of T.B. cleaner into the T.B. to clean any residue. Also if that works throw a bottle of gas treatment in.

When you turn the key on do you hear the pump start and shut off? Does it keep running? If you have anywhere over 75,000 miles it's a good chance your fuel pump died. You are not getting fuel to the rails? Can you check the fuel before your fuel filter. That will give you a good indication if the fuel pump is bad or not. You could turn the key on, and if you do not hear the pump come on hit the bottom of the fuel tank with a rubber mallet. That may jar the pump to start pumping. Hope this helps.

Have you Checked the Fuel Pump and Filter???? It Sounds like you may not be Getting fuel to the Injection System. Let me Know. Please Rate my Response, I need all the Help that I can get!

Voltage regulator possible.