Cranks does not start

My truck ran and drove perfect a long trip home, then to work the next morning. On the way home I stopped at O'Reilly to put in some mtf. Went to leave the parking lot and it cranked but didn't fire. Since I have replaced coil and ICM, crank and cam sensor, and even the PCM. Fuel is pulsing and got pressure, but no spark arc the coil. There is no security system on this truck. Grounds are clean enough and connected. Tachometer doesn't bounce when cranking despite the new crank sensor. Please help my father and I have been pulling out our hair for a week.