Something wrong with fuel delivery?
Ok was driving home from a fishing trip, boat and trailer in tow when my truck died at 60 mph.Complete loss of power, RPM dropped to zero and all guages showed as if they would when first started. Fuel pump and relay all seem to function as in I can hear the click and initial whir of the start up process but to no avail the engine would not start. chocked and sputtered but would never start. let it cool and even open the gas cap to make sure there wasn't a vacuum lock and never could get to start. long and short of it was had it towed to my house, left it overnight with charger on the battery (drained it trying to start) low and behold it fired right up this morning. Any ideas?? No CEL 99 F150 4X4 5.4L 84000 miles.
Very similar article I found http://www.startribune.com/business/162120605.html

 

If it cranked when it shut off i would assume fuel issue or air issue. Check throttlebody easy clean job. Other than that could be loose wire on sensor killing engine spark. Next time check if you have spark.

 

I would check battery cables, and clean posts if necessary. Follow them where they go down to the starter, and check everything over. Like said above, seems like something grounded out.

 

Thanks SilentJoker. I did clean the throttle body the day after and also cleaned the MAF with spray cleaner. Checked all the intake systems also. Here is something that I just remembered after it wold not fire...while cranking the engine the fan seemed to turn very slowly compaired to a normal start up but the pulleys seemed to turn at the proper speed. Would a slipping serpentine belt have anything to do with this mystery? I have driven it since and all appears OK.

 

Pull your belt and try turning your pulleys. Check for any resistance. I had a 93 that an idler or tensioner pulley seized on me. Busted right off, dropping the belt and shutting down the truck.

 

Well guys I have no idea. Driven it multiple time since without the boat and trailer and nothing out of the ordinary. Plugged my computer in to monitor things and nothing is throwing any flags. I'm completely stumped. Thank you for all the suggestions. Maybe hook the trailer and get it under laod and see the reaction.