2002 F150 5.4 would not start after sitting for about a month in some VERY cold weather (-15). It would crank, but not fire. Suspected frozen fuel line, and noted no fuel pump whine when key was turned to run position. I thawed everything out and got it to fire momentary with starting fluid, and after I warmed the fuel rails with a heat gun. Disconnected the fuel pump harness and put 12 volts to the pump and nothing. YEAY, I now know it's the pump, although i wonder how it died so suddenly. Replaced the pump, and let it prime a few times by turning key to run position, and it started right up! shut off, put bed back down and finished up. Started again, backed out, hooked up my trailer and pulled it up to check tire pressure, shut off truck, Went to restart and IT's DEAD AGAIN!. Yes I can hear pump come on, but won't fire even with starting fluid, NO SPARK! Checked all fuses, swapped relay, HELP! This one has me by the short hairs...

 

If the pump runs, the PCM is alive to operate the pump relay.

If you feel there is no spark because the engine would not fire with starting fluid, that is not positive proof because the PCM fires all the coils in a fire order from coil drivers in the PCM one at a time.
You must check for spark in a more positive way to prove the possibility.
The coils and injectors are all supplied power from the same source.
The PCM supplies a ground to each coil and injector in the order.
Go to the front of the crank behind the A/C compressor and reseat the crank position sensor plug to be sure it's good.
Then check with a gauge the fuel pressure on the fuel rail to be sure you have fuel pressure.
After these possible causes are eliminated then it time to get deeper into the issue.
Good luck.