I have a 95 F-150 with a 4.9 six. The engine would turn over, but had no spark. I also have a E-150 van with the same motor. I have checked all the fuses, the dist cap and rotor, and the ignition control module by replacing parts one at a time from the van. I replaced the coil with the one from the van and the truck started. It ran for about twenty minutes and died. Now I have no fire again. Is there something electrical that would cause the coil to fail?