Posted by Steve Fay on Sunday, February 20, 2005 at 11:42AM :
In Reply to: OT: Cummins Troubleshooting posted by KBishop on Sunday, February 20, 2005 at 8:39AM :
I'm pretty good with diesels but had the same problem last fall with my '97. Mine would drop out at 2300 rpm then when I release the throttle she'd be ok. Got Bue to white smoke every time she lost power. I tried the fuel filter change, injector cleaner, cleaned the AFE filter, Changed conditioners and nothing worked. I finally sent it out and here was what the problem was. The lift pump was ok at idle @ 16 PSI as speed increases tye pump should have gone to a max of @ 35 PSI. It fel to about 6-7 PSI. I had a lift pump let go in my crane and the diagnostics were a whole lot easier. Another problem was a small crack in the fuel line. The last problem , was a small short in a fuel preheater that caused the small crack. Without the test equipment, which I don't have...I would never have found the problem. It would be just easier if the lift pump failed completely and you'd know...this just drives everyone bonkers. Good luck and let me know how you make out.