I am dealing with a problem with prolonged start on a 06 D12 engine since it became colder in the midwest.
Already checked for fuel leaks and replaced the water separator filter, main fuel filter, fuel return valve, installed new priming pump assembly. I don't see any bubbles in the fuel tanks while engine is running nor any bubbles in the water separator sight glass. Also there is no coolant leak or overpressure in the surge tank. Priming the fuel pump does not help, after a couple pumps the plunger becomes stiff.
Any ideas would be greatly appreciated
Batteries and starter are good. After sitting overnight the engine struggles to start as if there is not enogh fuel in the head, sputtering and blowing white smoke for a second when starting.
No codes on the dash or ToolTech