My f150 with a 5.4 triton v8 in the pass 3 weeks some time it does not wan't to start early in the morning and i leave it along for 4 or 5 hours and them it will start, i have change al the 8 spark plugs and the fuel filter wit the original for parts, i have also check the pressure of the fuel pump and it is fine, also the battery and all the starting components have been check and every thing is o.k., for the pass 2 days it has been in a ford mechanical shop and these morning it did not wan't to start and they connected the computer to the truck and it did not told them any thing,they have not found the problem.