i just replaced the heads and head gaskets in a 1997 f-150 xl with the 4.6l. got it all in and now the truck won't start. i checked and it is getting fuel up to the rail on the intake. i checked the coil packs and the number one is not getting a spark. i tried 3 other coil packs and all with the same result. it did start and run with the current coil packs before i pulled the motor and replaced the heads and head gaskets. it does crank over and acts like it wants to start but just won't fire...any suggestions???

 

did you set the cam gears to the right positions along with the crank at cyl. 1? that would be the most likely thing i would assume.

 

yea, i set the cam at 8degrees before top dead center. there was no bang or popping or back firing. so i am pretty sure the timing is right and i had it set at number one cylinder before i tore it apart