Sorry for the long story, but if anyone can get this, it's you guys.
If you've ever had the "joy" of trying to hunt down an issue with a vehicle by throwing part after part after part at it. Then trying everything that has ever been said on a forum for fixing said problem and come up short. Then you know how I was feeling yesterday.
I have a 6.5L Turbo Diesel that was hiccuping and stuttering, under load at first, then slowly it kept getting worse, to the point where it was bucking and almost stalling at idle.
I had gone down the whole list of easy to swap out parts. Fuel filter, check. Lift pump, check. PMD, check. Oil Pressure Sensor, check. The only thing left to replace in the fuel system was the Injector Pump. I was dreading it, and the five hundred dollars and 8 hours worth of work I would have to put in to R&R that thing. I finally bit the bullet and installed the pump over a couple evenings. Got it all back together, and turned the key, it took a couple cranks to get it going, but it was running. Damn, was I excited that it was running again, and seemed to be idling good after it cleared out the air int he lines. Then, I took it for a test drive.
My excitement and elation quickly sank below the waves frustration, exhaustion, and anger, as the truck started to buck and spit and sputter again. All that time, all that money, all down the drain and nothing to show for it.
So I took a break, and decided to start back at the beginning. The fuel filter, I had replaced it about a month ago when it first started hiccuping, so it should be good, right? Thankfully the filter on a 6.5 is easy to get at, it just unscrews from the filter manager on the back of the engine. I remove it and low and behold, it's covered in crud. I'm kinda shocked by just how much there is, abut also a little elated. Could it really be this simple? I look in the holder for the filter, the bottom of the unit is just completely cover in brown crud. I take the unit off, clean it out with compressed air. While I have the lines removed I go and remove the lift pump and from the pump lines I blow compressed air through them. If any crud was lodged in them, it's not now!
After I;m satisfied it's all clean, I put it back together. I prime the system and everything looks good. It's now time, I tentatively turn the key. She fires up very quick this time, my heart races. I back it out of the driveway, it's time. I put it in first, runs good, I go to second and floor it. Nothing but a steady climb of the RPM's as the turbo spools! No hiccups, no bucking, nothing but smooth power. It's fixed.
What I choose to believe is that the old injection pumps internals were breaking down and that caused the crud to get on the wrong side of the filter from the fuel return on the pump, clogging the lines. Also with three hundred thousand miles on it, it was probably nearing the end of it's life, so it wasn't a wasted five hundred dollars and two nights of work, that's my story anyways.
So moral of the story, check EVERY simple thing first, don't get lazy and skip over something. If I had looked int he bowl when I replaced the filter the first time, I might have been able to avoid all this frustration.
