Truck sometimes wont start

I have a 2001 Ford F150 Supercrew. It has a 5.4L V8. I’m the original owner and the only repair Ive had to do on the truck was replace an ignition coil pack last summer (other than routine stuff). IN the last few months Ive run into a situation if I l don’t hold the key to the start position until the engine is running it wont start until I let the truck “rest” for an extended period of time. Once I have one of these false starts no matter how long I crank the engine, pump or don’t touch the gas pedal, it wont start. The cylenders are not firing. The battery is good. There is fuel in the tank. I dont get a service light. This has happened to me twice so far and Ive left the truck over night and it restarted fine in the morning. Im guessing its a computer or sensor issue, but since there are no service codes, where does one start?