We own a 99 HR Endeavor with the 5.9 Cummins.Last year after returning from a 4 month winter trip we wanted some maintenance done. My mechanic called me and told me he had trouble starting the MH. He determined it was the electric fuel pump and replaced it. We went on our 14-15 winter trip and had no problems.In spring we wanted annual maintenance. My mechanic informed me he had the same problem again (starts runs for 3-5 seconds and dies) and replaced the pump again. It happened to him yet again and this time he installed an OEM pump. I brought the coach home. Tried to start it a couple of weeks later and it happened yet again. This time he thought it was sucking air somewhere in the line from the tank to the pump. He tightened everything and it started. He called me last Wednesday and said it was all set. They had checked it at least 15 times and it started. We went to pick it up Friday AM and same thing happened.Any of you wise people have any ideas?

retiredtravelers2013 wrote:We own a 99 HR Endeavor with the 5.9 Cummins.Last year after returning from a 4 month winter trip we wanted some maintenance done. My mechanic called me and told me he had trouble starting the MH. He determined it was the electric fuel pump and replaced it. We went on our 14-15 winter trip and had no problems.In spring we wanted annual maintenance. My mechanic informed me he had the same problem again (starts runs for 3-5 seconds and dies) and replaced the pump again. It happened to him yet again and this time he installed an OEM pump. I brought the coach home. Tried to start it a couple of weeks later and it happened yet again. This time he thought it was sucking air somewhere in the line from the tank to the pump. He tightened everything and it started. He called me last Wednesday and said it was all set. They had checked it at least 15 times and it started. We went to pick it up Friday AM and same thing happened.Any of you wise people have any ideas?Look for a bad GROUND wire - either the direct or a secondary to the Battery - if he still has the old pump do like most mechanics do, "Check it out on the bench to see if it is truly the Problem" if it works on the bench then likely the ground.Over the years the grounds become an issue, on many occasions.JMHO,

I have the same year endeavor with the 5.9 cummins. Recently mine started acting up as well. Doesn't want to start. You can crank and crank, never starts. If you bump the starter that should get the fuel pump turned on and pressure built so you can start it. If your pump is not putting out the pressure it should, it may take several tries before it starts. That's what mine is doing. I don't know if mine has the original lift pump, but the previous owner already had a lift pump die and take out the very expensive VP44 pump. I am going to upgrade my lift pump to something from FASS when I have a few extra dollars. From all the reading I have done, the factory lift pumps are not that great.

Thank you for the tip regarding the ground.And to Glamisorbust. My mechanic told me at least two of the times he tapped the pump and it worked. Does not make sense that it does not have enough pressure to start but enough to run at 70-75. Does anyone have any logic? I have looked at the FASS, but they are pricy indeed.

Have him look for an air leak past the lift pump. On the fuel rail assembly. You get a tiny leak there, and you get those symptoms. A leaking banjo bolt will cause that.If he's tapping the pump and it starts right up, but he's replaced it already, I think that just might be a coincidence, or maybe the tap is vibrating up to something else.I feel for you and your mechanic though. Tracking down an intermittant problem is the worst.

Don't know about the 5.9 but most deisel engines also have a fuel shut off solenoid in the injector pump circuit. If the spring gets weak in these they will intermittently fail causing the engine to run a brief time then stall.

5.9 Cummins fuel problem (Still) | Good Sam Community

17 Replies

retiredtraveler
Explorer
Sep 07, 2015
Thank you to everyone for all the suggestions. I will make a list for my mechanic and present it tomorrow.
glamisorbust
Explorer II
Sep 07, 2015
What I have read online has told me this: A weak or failing lift pump will ruin a good VP44 injection pump(expensive). However, the VP44 is strong enough to suck fuel from the tank even though the lift pump is not working properly.

However, letting the VP44 suck fuel is bad because it will overheat and get ruined also.
jtfcons
Explorer
Sep 07, 2015
Don't know about the 5.9 but most deisel engines also have a fuel shut off solenoid in the injector pump circuit. If the spring gets weak in these they will intermittently fail causing the engine to run a brief time then stall.
Jim
Explorer
Sep 06, 2015
Have him look for an air leak past the lift pump. On the fuel rail assembly. You get a tiny leak there, and you get those symptoms. A leaking banjo bolt will cause that.

If he's tapping the pump and it starts right up, but he's replaced it already, I think that just might be a coincidence, or maybe the tap is vibrating up to something else.

I feel for you and your mechanic though. Tracking down an intermittant problem is the worst.
retiredtraveler
Explorer
Sep 06, 2015
Thank you for the tip regarding the ground.
And to Glamisorbust. My mechanic told me at least two of the times he tapped the pump and it worked. Does not make sense that it does not have enough pressure to start but enough to run at 70-75. Does anyone have any logic? I have looked at the FASS, but they are pricy indeed.
glamisorbust
Explorer II
Sep 06, 2015
I have the same year endeavor with the 5.9 cummins.

Recently mine started acting up as well. Doesn't want to start. You can crank and crank, never starts. If you bump the starter that should get the fuel pump turned on and pressure built so you can start it. If your pump is not putting out the pressure it should, it may take several tries before it starts. That's what mine is doing.

I don't know if mine has the original lift pump, but the previous owner already had a lift pump die and take out the very expensive VP44 pump.

I am going to upgrade my lift pump to something from FASS when I have a few extra dollars. From all the reading I have done, the factory lift pumps are not that great.
Busskipper
Explorer
Sep 06, 2015
retiredtravelers2013 wrote:
We own a 99 HR Endeavor with the 5.9 Cummins.
Last year after returning from a 4 month winter trip we wanted some maintenance done. My mechanic called me and told me he had trouble starting the MH. He determined it was the electric fuel pump and replaced it. We went on our 14-15 winter trip and had no problems.
In spring we wanted annual maintenance. My mechanic informed me he had the same problem again (starts runs for 3-5 seconds and dies) and replaced the pump again. It happened to him yet again and this time he installed an OEM pump. I brought the coach home. Tried to start it a couple of weeks later and it happened yet again. This time he thought it was sucking air somewhere in the line from the tank to the pump. He tightened everything and it started. He called me last Wednesday and said it was all set. They had checked it at least 15 times and it started. We went to pick it up Friday AM and same thing happened.
Any of you wise people have any ideas?

Look for a bad GROUND wire - either the direct or a secondary to the Battery - if he still has the old pump do like most mechanics do, "Check it out on the bench to see if it is truly the Problem" if it works on the bench then likely the ground.

Over the years the grounds become an issue, on many occasions.

JMHO,

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5.9 Cummins fuel problem (Still)

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