98 f150 4.6l won't start when it's cold

My 98 f150 won't start most of the time when it's 20 or below outside but once it starts warming up starts fine. I've tried fuel treatments to no avail. This morning i checked the valve on the fuel rail and there was no pressure with the key on. I did not hear the fuel pump either when i initially turned the key. Does this sound likea fuel pump starting to go bad or maybe a relay? If it stays warm out I never have a problem.