Visit our Popular Forums

wxbuoy · 03-15-2014, 10:41 AM

Was taking the moho to a shop a few hours from home to get the A/Cs done.

I was unable to get above 45mph. Just had it out for a drive last week-end and it ran like a bat out of H.... I made it back to the storage lot.

Cummins 5.9 BTA with Allison transmission.

I checked all the fluids. Transmission was low and topped it off. Drained fuel separator, nothing noted.

Fuel filters are a year old with less than 100 miles in them.

Engine idles great and revs with no load just fine.

Any ideas before I call Good Sam to arrange a tow to the nearest shop would be appreciated.

I am going to crawl under and check the fuel line. There is not a secondary pump that i know of nor was one needed during the 1400 miles I have put on it in the last 15 months.

Thanks!
Dave

masseyfarm · 03-15-2014, 11:57 AM

Turbo Boost connection failure? Is the connection tight on the intake manifold fitting?

Dave

wxbuoy · 03-15-2014, 12:08 PM

Dave,

Will check but I was still getting 10 lbs of boost at 40 mph.

**GCinSC2** · 03-15-2014, 12:26 PM

Dave,

If you have a boost gage, was the 10 PSI normal? I've got a '97 Dodge 5.9L and it makes mid to upper 20's IIRC under heavy load acceleration and my '05 Dodge 5.9L gets 28-29 under hard acceleration. I know, not a motor home, but still from the 5.9L family. Checked the air filter housing for critter debris? Do you have an EGT gage also?

Gary

**moosetags** · 03-15-2014, 12:42 PM

What you are describing is a classic symptom of fuel restriction, typically at the fuel filter. Since your fuel filter is new, possibly there is some kind of restriction in the fuel line.

Brian

Melody Ranch · 03-15-2014, 12:47 PM

What Brian says above.

Valacidor · 03-15-2014, 12:55 PM

wxbouy,
Have you by any chance filled with bio-diesel lately? If you don't normally run it it can losen crud in the tank and lines and plug a fuel filter very quickly.
TomJ

wxbuoy · 03-15-2014, 01:09 PM

Dave: looks like everything is tight

Gary; no egt gauge. 10lbs is about right Only time it goes higher is if I am going up a steep incline at 65 mph. Checked the air filter all is good and no critters

Brian; no signs of crimped fuel line but they way it is run who knows.

wxbuoy · 03-15-2014, 01:11 PM

TomJ; no haven't used biodiesel yet, that I know of. But will get new filters just in case.

wxbuoy · 03-15-2014, 01:13 PM

Thanks for all the suggestions. I am off to napa to get new filters and see if that works. I have a tow scheduled for monday morning worse case scenario.

masseyfarm · 03-15-2014, 01:14 PM

The "shut down solenoid" on these has been updated with a new style.
The solenoid requires power to open, and if it hangs up, will give you that loss of power feeling before it quits for good.

Dave

wxbuoy · 03-15-2014, 01:18 PM

Dave; Never heard of that. Were is that located?

masseyfarm · 03-15-2014, 02:08 PM

Bottom or top of fuel pump.

Look on the Dodge owners site for some info. I had to change mine on my 8.3 back in 2010 on the road in Utica NY.

Hang on, I will get you a picture. Cummins has an upgrade that is heavier than the original but bolts in the same pattern.

You can manually operate it in an emergency if that is the problem. Just tie it up or pull it down.

Dave

wxbuoy · 03-15-2014, 02:15 PM

Dave

Will do thanks!

masseyfarm · 03-15-2014, 02:23 PM

See my picture in last post.

Dave

Quote:

Originally Posted by wxbuoy

Dave

Will do thanks!

mayco · 03-15-2014, 02:26 PM

Sounds like fuel restriction, you changed the lower filter but did you change the upper on the motor? Just noticed you have a cummins, probably different set up than the isuzu.

wxbuoy · 03-15-2014, 04:52 PM

Well $217 dollars later...Fuel/Water separator filter, secondary fuel filter, air filter and a belt for good measure...... I didn't need the belt, but wanted to have a spare.

Will replace first thing tomorrow morning. Having a glass of wine to dull the pain. Had to cancel all my plans..... Oh well, the bright side is it crapped out close to home and kept going until I got there! Called Good Sam and have a tow scheduled for Monday a.m. If they are as good as everyone says, I will up my 1 yr to a 3 yr membership!

I am hesitating on how far I should go in trying to fix this or just let the professionals deal with it. I am no where near mechanically inclined! The only thing that keeps me going on my own is the fact that every $ I spend on paying someone to repair it is one less $ for rehab! I do fear though replacing all this stuff and it being something that I never would have thought of.....

Thanks again for all the help!! Will let you know how it goes tomorrow!

ON the bright side, I was going to cut a hole in the bedroom floor to be able to access the fuel pump if ever needed..... That can easily be done at this point of the reno. Only issue is how to cut it and frame it that a door/hatch/access panel will fit and still be structural.

Thanks again!!!! This forum is great!

masseyfarm · 03-15-2014, 05:08 PM

If this is/was a diesel, I don't think there ever was a fuel pump at the tank. It would be engine mounted. Check that out before cutting holes in the structure???????????????

Dave

wxbuoy · 03-15-2014, 07:35 PM

Dave; it is a diesel. Cummins 6BTA, it has a lift pum and a fuel pump mounted on the engine. I have ti reach up around the tank to make sure there isn't a tank pump as well. Thanks!

Smartstream · 03-15-2014, 09:10 PM

Diesels are pretty simple. To run they need compression, heat and fuel. Because you are running and showing normal boost and don't have a significant internal problem like a broken piston or something, I would assume the compression and heat are there. As mentioned by others fuel is probably the culprit.

In checking for fuel most people look for plugged filters but another culprit is air. A poor seal on the filter or fuel line connection will allow air into the system and cause power loss. Also a plugged or restricted return line can cause power loss. At a shop I worked at we had bunch of air leak problems that turned out to be a shipment of filters with a defective crimp on the base to can. Caused a lot of head scratching.

You might disconnect the return line somewhere after the injector pump and connect a clear plastic tube to run into a bucket. Start the engine and look for a good flow with no air bubbles. When you change the filters see if they are full to the top with no air space. Sometimes this is hard to do depending on where the filters are mounted. With new filters check your return line for bubbles and compare flow.

It is usually something simple just hard to find. Good luck.