Hey Ken
Check your fuel pressure at the rails. Even with a new pump, if the fuel pressure sensor is conking out, the PCM may not see enough pressure to enable the injectors. A weak or leaking injector can also cause rail pressure to bleed down after sitting. Then check your camshaft or crankshaft position sensor. If the PCM doesn’t get a proper RPM signal, it won’t fire the injectors. When we par out these trucks and test the sensors, we have seen them fail intermittently with heat soak, then work again after cooling off.
If your alarm security light flashes rapidly during the no-start, you may have the passive anti-theft getting in the way. Finally check for corroded grounds (especially near frame rails or battery-to-block). That can cause intermittent no-starts. Harness chafing around the fuel pump driver module, frame rail, or PCM wiring is also a common issue we have seen.
Hope that helps. Let us know if we can help with any parts - all used but always OEM. Also happy to keep brainstorming is none of these tips resolve it.
when the truck runs it runs great .... does this make any sense?