Since the cold weather, the truck won't start. It's warmed up now still won't start. It will crank. I pulled off plug wire, held it next to enngine block and could see spark arching to engine bl;ock while someone tried cranking. It seems ignition electic is not the problem. Is there an injector relay, switch, etc.? Has new fuel pump and fuel filter. It just crank, crank cranks with nothing taking.