Truck is high milage, 410,000. Last summer replaced all injectors, high pressure oil pump, injector pressure regulator, injector wiring harness, and all glow plugs. When below 30 degrees if I do not plug in the truck, it will not start and run. Batteries are one year old, crank speed is good warm. During cold cranking I have white smoke from tailpipe, I also notice the crank speed increase, I assume from the fuel in the cylinders. I have an OTC scan tool but have not checked injector pressure during cold cranking. I also can perform an injector test with this tool but have not done it cold. I'm wondering if the engine is just worn out to the point that the compression won't fire at the cold temps. I have limited diesel experience, especially diagnostic. I run Stanadyne additive, NAPA 15-40 oil, Motorcraft filter.

I recently discovered this site and would be greatful for any diagnostic direction.