I have a 2004 new bodystyle 150 with a 4.6L
Never had any problems like this before. Took to carwash few weeks ago and sprayed under the truck and fenderwells. Did not open hood and spray. Truck would try to start but wouldn't. Took about half an hour of trying and it finally started. Didn't have any problems since. Mechanic said try replacing coil boots. I replaced. Now it was raining really hard last night and there was alot of standing water running down the streets as I was driving. I ran several erands and had no issues. Went to start truck this morning and it would not start. Would not even try. Just turned over. I set a small heater on the radiator shroud to blow hot air across the motor trying to dry it out. Only had on about 2 minutes and tried to start and it fire right up. Anybody have any ideas? Something must be getting moisture. Also, check engine light never comes on and it is not throwing any codes. I'd appreciate any help. Thanks.

 

(2004 5.4 screw) Mine was doing this about 2 years ago. Then one day I was driving in the rain and shut it off and it didn't restart. We had to tow it home. We found that there is a fuel managment box on the frame above your spare tire. It was cracked and it had corroded so bad it wasn't making a good connection. It cost about 80 bucks to fix and was back up in running. I beleive it did make my fuel pump go bad not even three months later. It is worth a check