I'm having an intermittent code 559 over the last month. The enigine derates for several seconds, then power returns. This can occur multiple times simultaneously, or it can go hours or even days without occurring. On really cold days it will idle fine to warm the truck up, but once you attempt to move the truck, the code comes on and the truck, will slowly sputter and die this occurs both loaded or bobtail. Once the lift pump is cycled, it will start back up, run fine, code comes on, then it starves for fuel again, and shuts down. All fuel pressure tests check perfect. It will not replicate the code issue in the shop while connected to insite.
Recent parts changes in the last 3 weeks: Fuel Filters, davco system housing, fuel pressure relief valve, lift pump, fuel actuator on pump, fuel rail pressure sensor.
Parts in the last year:
Full set of Injectors, high pressure pump, gear pump, all hard fuel lines. ECM, engine harness.
Have you taken the head off the high pressure pump and inspected for internal damage? 559 is the notorious fuel pump of death code. And yes it can definitely be intermittent.
Did you run a leakdown test on it?
When we did the pressure test, it stayed steady @ 28900-29300 psi. The mechanic didn't officially time it but we watched the pressure drop to -1200psi after a few minutes. On another note, Today it has developed a loud squeal on starting but it is now choking down, starving for fuel and dying much more quickly than before. We haven't been able to pinpoint the squeal as of yet....
(03-07-2022 )Heavyhaulmark Wrote: [ -> ]When we did the pressure test, it stayed steady @ 28900-29300 psi. The mechanic didn't officially time it but we watched the pressure drop to -1200psi after a few minutes. On another note, Today it has developed a loud squeal on starting but it is now choking down, starving for fuel and dying much more quickly than before. We haven't been able to pinpoint the squeal as of yet....
loud squeal?
maybe to the obvious and remove all the belts... check to see it if it a pulley or, alternator, or AC compressor seizing up?
(03-07-2022 )Rawze Wrote: [ -> ] (03-07-2022 )Heavyhaulmark Wrote: [ -> ]When we did the pressure test, it stayed steady @ 28900-29300 psi. The mechanic didn't officially time it but we watched the pressure drop to -1200psi after a few minutes. On another note, Today it has developed a loud squeal on starting but it is now choking down, starving for fuel and dying much more quickly than before. We haven't been able to pinpoint the squeal as of yet....
loud squeal?
maybe to the obvious and remove all the belts... check to see it if it a pulley or, alternator, or AC compressor seizing up?
The sound is coming from around the fuel filer area, maybe the fuel pump area, I'm going off what my driver is telling me. We have it at a cummins dealer now. I'll update with the prognosis. I'm fearing it's the fuel pump again.....
(03-07-2022 )Heavyhaulmark Wrote: [ -> ]...
The sound is coming from around the fuel filer area, maybe the fuel pump area, I'm going off what my driver is telling me. We have it at a cummins dealer now. I'll update with the prognosis. I'm fearing it's the fuel pump again.....
make sure it is not this issue...
http://rawze.com/forums/showthread.php?t...0#pid70510