Have a bit of a problem, I drive a 03 6 liter truck has around 225,000 miles on her.
Truck had been running good. then it lost power and shut down while driving, had to get her towed as she won't start. Shop looked at camshaft sensor, fuel pumps was told it was the fuel pump after what seemed like forever, got the truck back. On the way home truck was surging now an then the weather had turned colder and the truck had been sitting at the shop for 2.5 months with summer fuel in her, thought it was maybe the filters and it needed some conditioner in it. Did that trucks seemed to run OK. Next day was working and it lost power climbing a little hill ( no light came on to show a code) took my foot off the pedal truck kept running but slowed down to 30 pushed the pedal again and it picked up power after that the thing ran fine again lots of power turbo was working good.Got home checked the filers again they were good air was good no leaks, went for a test run stalled out right away restarted surged and lost power again.Took it out again today did the same thing stalled out and after restarting it kept losing power but this time the glow plug light came on, did this three more times then started running great again. I am thinking it is a wiring problem maybe the harness which has been replaced 3 times, or a short in the fuel systems, If any one can help point me in the right direction I would appreciate it