I have a 2001 ranger 3.0 that I recently changed the the engine in and now I can’t get it to start. It will turn over the engine and when you first turn the key the injectors come on for a second and the shut off and it will just spin over. I don’t think it has anything to do with the wiring harness because I had the new one on and then tried the old one. If I spray starting fluid in it it will start right up and the fuel pump is getting fuel to the rail. And at this point I think it has something to do with pats because I only have one key for the truck

 

Welcome to the forum

Does the CEL(check engine light) come on with key on, that means computer has booted up
Does the CEL go OFF when cranking engine, that means computer is getting a timing signal from crank sensor

Did the 2 wire Cam Sensor get plugged back in, top rear of engine bay, on 3.0l no cam sensor timing can cause a no start

PATS disables starter relay, fuel pump and fuel injectors, in a 2001 Ranger not just the injectors
There is also a THEFT light on the dash that will start to flash rapidly if PATS has shut down the system

All 6 injectors being disabled is a long shot, but if it starts by adding fuel manually then spark is working so computer is working
Each injector shares a 12volt wire with the other injectors, the red wire, if you can test one of the red wires to see if it has 12volts with key on

Each injector has one Ground wire that runs back to the computer, the computer uses that ground wire to open each injector, but ONLY after engine starts to spin
To have all 6 wires fail would be, well, unlikely
More likely would be the one 12volt wire losing its connection somewhere

 

Would only having one key for the truck cause the injectors not to fire off because when I hook up a FORScan to it it throws a code for only one of two keys available

 

If more than one key is already programmed into PATS memory then engine should start just fine with any one of those keys, there is no way for PATS to know you lost a key or 2 or 3, lol
All PATS keys have a unique 40 or 80bit number embedded in an RFID tag in the handle, that number is programmed into PATS memory at the Factory, usually a new vehicle comes with 3 PATS keys, so 3 numbers are in PATS memory when new
New PATS Keys can be added but must have minimum of 2 PATS keys once you start programming mode, can be one old key and one new key, but must be 2

If you were trying to program a new key then no, you can't program just one key, must have 2 different keys(no clones), minimum, or PATS can't be programmed and will be in lock down mode until it can "see" two different PATS keys added in Forscan programming mode
It will ask you to insert the 2nd key, if you don't have one then lock down, at this point all the old keys have been erased, so no going back

 

I figured out the key problem it has nothing to do with it and the parts guy gave me a faulty key, but it’s still not getting fuel I checked the pressure and it’s around 20psi so I’m thinking a new fuel pump and filter

 

Yes, 20psi would be an issue on 1998 and up Rangers, expected is 55-65psi