Power Loss While Climbing Hills

[Ted Carbonaro]

2006 Monaco Camelot 400 Cummings

Recording inconsistent power while driving up and down the hills of PA. Towing Honda CRV on trailer. Sometimes it cruises at 55–60 mph uphill in 5th or sixth gear. Other times, it only does 35 to 40 mph in 3rd or 4th gear on a similar incline. 
At times, engine bucks underload while climbing. Also, check engine light has come on two or three times during bucking. Note: prior to putting in 40 gallons of diesel, there was no issue with bucking. And, one extremely steep hill resulted in a 35 mph climb. 
Thanks!

[Bob Schmeckpeper]

Have you changed your fuel filter lately. Thats what mine did. I always carry an extra filter.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited February 13, 2022 by Bob Schmeckpeper
Fixed a word

[Dr4Film]

Yes, first and most important, change out both fuel filters ASAP.

[Poppa G]

Drain water fuel separator,change both fuel filters.You should always carry extra fuel filters.When you change fuel filters you don’t have to fill them with fuel before you replace them, after changing them turn your ignition on for a few minutes to allow your lift pump to fill them,then fire her up.   

[cbr046]

8 minutes ago, Poppa G said:

Drain water fuel separator,change both fuel filters.You should always carry extra fuel filters.When you change fuel filters you don’t have to fill them with fuel before you replace them, after changing them turn your ignition on for a few minutes to allow your lift pump to fill them,then fire her up.   

Drain the fuel from the separator (on the secondary filter) into a clear cup.  Check for water. 

You can pre-fill the primary filter but NOT the secondary filter, and if you fill the primary filter pour in through the holes around the edge (not into the center hole).  Lift pump runs for about a minute before it shuts off filling the secondary filter, but yah . . . cycle the ignition switch 4-5 times to fill the secondary filter.

If you're still driving monitor your boost gauge while loosing power.  You'll see the loss there easily.

- bob

 

[Bob Schmeckpeper]

Take the old filters , cut them open and check for alge. Hold filter paper up to the sun to see if you see anything through the filter media. In mine I detected alge. So I ggot some treatment for it. I carry 2 filter. Because if you do get alge you can clog the new one up you get it under control.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Paul Busch]

I had the same problem with a 2005 Detroit diesel. Changed all fuel filters and still a problem. Was told need injector #4. Turned out was injector wiring harness. Different motor,maybe the same problem. Good luck.

paulb

[Old Dog]

Also check the boot clamps to/from intercooler & turbo i.e. reduced boost. Easy stuff frist.

These rigs should come with fuel, boost and egt gauges, would make troubleshooting much easier.

[Just Jim]

Yep, check the fuel filter, but also the AIR filter.  Either will result in a loss of power.

[Nancy Knaus]

We have a 2010 42 SKQ 

we had that problem, I think it was part of the egr system.  I took it to Cummins in Jackson, Tn,  they first cleared the codes in the hope that was the problem, it wasn't.  He removed the top part of the egr manifold, it was okay, then went to the bottom, all the ports were blocked with carbon, cleaned them out, new gaskets.  It now has so much power now.

I'm sorry about not know the technical names of these parts.  I just watched the service manager 

We also owned an older Monaco, it's been years ago,  it had no compression in one of the cylinders.  We ended up replacing the motor.

[Ivylog]

Had similar on our 04 Dynasty and changing filters didn’t help plus it was all of the time above 45 mph. Replaced lift pump before I learned it only runs for 30 seconds to aid in starting…didn’t fix the problem. Over the weekend found the troubleshooting guide for  the code:

1) change the fuel filters… done.

2) check for air in the fuel. Bought 6” of clearance plastic tubing. Installed before 2nd filter and could see small bubbles in the fuel.

Because of a big change in temperature, the big fuel hose at the tank (which was very tight) let air in. Put back on, not near as tight.. bubbles were gone and problem solved.

[Ted Carbonaro]

Thank you to all for your suggestions! We changed the fuel filters and it’s running much better. And, there was a lot of algae present on the old filter. 

What would you suggest to getting the algae out of the system, as it seems it still has a loss of power.

Thank you!

[Chargerman]

Algae is a PIA to get out of the system. Suggest you buy a bunch of fuel filters for starters. The new one you put in is already likely full of it and restricting flow. You will need to treat your tank a couple times with a heavy dose of biocide. Then use it every other tankful going forward. Treat the tank with a heavy dose then take short runs until you feel a loss of power and change the filter. Might take a half dozen filters before you can feel confident to travel any real distance. 
 

good luck!

[Just Jim]

I created a mostly disposable redneck fuel tank filter system to clean mine.  I used a old garden hose a pump and a cheap house hold water filter canister.  Buy about a dozen of the filters and changed them out about every 5 minutes.  I considered draining the tank and cleaning, but it was almost full and I didn't want to fool with trying to move 100 gallons into barrels, etc.  You basically pump the fuel out, it runs through the filter and right back into the tank.  Make the out hose long enough to reach the bottom and move it around to stir up all the junk that has been accumulating for 25 years.  It worked really well and then treat heavily to make sure it doesn't come right back. 

[cbr046]

I had a total clog coming back from a trip last year.  I basically ran out of fuel and sucked anything at the bottom of the tank into the filters.  Did a lot of walking that day. 

I was worried about algae so I started a regimen of Biobor JF each fillup.  I expected more clogs as Biobor basically causes the algae to drop out of solution . . . to the fuel pickup!  Biobor JF is also a fuel lubricant, compensating for the lack of lubrication in ULSD fuel.

Next step was to install a fuel pressure gauge mounted at the inlet to the CAPS pump (main fuel pump to the injectors) to monitor fuel flow.  Any clogs would result in a drop in pressure . . . . . except the lift pump only runs for 60 sec (mine did, anyway) so it was always sucking fuel from the tank.  The lift pump was seeping so it was probably sucking air through the leak.  Not good for injectors.  And the lift pump stopped lifting anyway. 

Final step was installing a FASS "fuel air separation system" mounted where fuel comes out of the tank.  FASS uses a 140 um filter then a 2um filter before pushing fuel to the OEM primary and secondary filters.  I expected the 2um filter to clog quickly but so far, 1,000 miles later, no problems. 

A little more expensive than Jim Bob's solution but much more confidence going down the road.

Don't forget to carry extra filters with you and the tools to change them.  On the R8RR chassis / ISC engine the secondary filter is a real PITA.  Disconnect the starter battery cable if you do that one.   

- bob