I have a 2000 f250 that has 366,000 on it that is really hard to start when it sits over night and even harder when its cold out. and it white smokes like a mother. After it starts it takes like 5 minutes of driving to clear out and run smooth. Once its running smooth and good then im usually at my destination so i shut it down go do whatever im doing them come back like 2 hours later and the truck will start but run like its missing and has no power. Ive replaced the Gpr, glow plugs, hpop and injector pressure sensor all in the last week and I still have problems. My glow plug system checks out fine and my harness through the valve cover gasket is making connection. Any experts out there that can help me out im really frustrated.