I have a 2001 Ford F150 Supercrew 4WD 5.4 V8. Sometimes at start up it won't Start when this happens I have noticed the fuel pump doesen't hum when the key is first turned on. I have swapped the relays inside the truck under the dash rotating it with the other ones like it to see if the problem moves and it didn't. I have also replaced the fuel filter. I have tried the spare set of keys with no luck. If I keep turning the key off and on eventually the pump will hum and the truck will start right up and run with no issues. Sometimes it will go weeks without having this issue and suddenly it will do it twice in the same day. It does appear to happen more often when the weather is cold. Also I stopped by Autozone and had the codes pulled and the only thing they said it had was a bank 1 and 2 02 sensor faults. Please help the next thing I know to try is changing the fuel pump.
Thanks for your Help Jason