Fuel filter and loss of power

[wilson8ford]

The latest on my loss of power/filter issue: I replaced both filters. I liked Ron's idea of putting two ball valves on the primary filter to make changing filters easier:(not sure if the picture will up load). The primary filter is easy to reach with a 3" filter wrenth; however, the one on the motor is a bit closer quarters, so I purchased a Harbor Freight adjstable filter plires. I had some other work to do. When I purchased the mh, I know it had some rusted seal planes, so I replaced them. Winnebago carries the exact replacement--the holes and all are perfectly placed. At any rate, after that job was complete, we took the rig for a drive. All worked perfectly, so the filters were the problem. I cut the apart and the primary one and it had some slime in the settlement bowl, so I purchased some BioGuard to treat the fuel. The fuel tank has a settlement recess, so I drained about a gallon of fuel to see if there was any kind of trash in the fuel, but the fuel that came out, after the rig had been setting several days, was clear. I now have a couple extra filters, so if this happens again I think I can make the filter change in 20-30 minutes.

Thanks to all for your suggestions.

[Vanha Pieru]

Well we finally ransomed our '02. This has the Cummins on a freightliner frame. No pre-lift pump filter. Bad fuel I guess, caused rust to get into the lift pump.
New lift pump, warranty people won't cover it because rust is a "pre existing condition".
Put that on, and shop installed a pre-lift pump filter to prevent similar future issues.
Took off for home, got to first hard pull hill, SAME problem as before. Now they say injector pump is bad.
Warranty people deny this one too, same reason.
Test drive, still problems, bad injector this time.
Caused by(per warranty people), you guessed it that rust again. Interesting how it got all the way through a sediment bowl, two pumps, a fuel filter, and into an injector!
ANYWAY, IF you have a pre2002 Freightliner frame unit, get a filter added on pre-lift pump! Could save you a ton of money, as in, about $9grand!!
Damm poor design for sure.
The shop guys did a nice job of installing the filter easy access, thanks.

[David K]

Right after I got my 2002 Ultimate Advantage, I had the people at Cummins South install a dual fuel filter arrangement on the back rail of the frame. The 8.3 Cummins comes with one filter located above the starter on the engine -- very difficult to get to. The first filter is before the lift pump and the second one is before the injection pump. Best $450 I have ever spent as I can now change both filters easy. Just as a note to any 8.3 engine owners with dual fuel filters installed -- don't use any filter with a less than 10 micron filter rating (don't ask me how I found out) as any smaller opening will fuel starve the engine.

[Mr_D]

I thought CAT used a 10 micron and then a 2 micron filter on their engines? We had a 3126 in our 2000 Dutch Star and I think that's what it had. But after 13 years I don't remember for sure.

[Arizona Anni]

I am having similar issue with power loss. I have a 05 Journey with 330 Cummins on a freightliner chassis. Would love any further feedback.

[AFChap]

Update on my April 2015 post in this thread where I mentioned changing fuel filter on the road in 2013 and again in 2015 due to loss of power. My 02 Spartan chassis came with just one fuel filter. In 2017 I again had loss of power on hills. Changing the filter did not help. On most hills between Kerrville & Albuquerque we would fee some loss of power, and sometimes a little "bucking". I took it to Cummins SW in Albuquerque. Long story short, we had to have the fuel tank dropped & cleaned, all fuel lines & lift pump replaced, and I had them add a second filter before the lift pump. All due to "crud" in the fuel system.

Since buying this coach new ... now at 120k ... I have always bought fuel from truck stops or large volume locations. I have always filled the tank before parking the coach for more than a few days. And I used Howes Diesel Treat occasionally early on, and Power Service Clear Diesel in more recent years.

After doing all the work, plus replacing the cracked manifold, ...about $7k all together ... Cummins SW told me I need to be using a biocide with EVERY fillup. They recommend Power Service Bio Kleen. BECAUSE: 1) the advent of ULSD fuel removed sulfur which killed microbes; and, 2) the advent of bio-diesel introduced stuff that microbes thrive on. Bio Kleen can be used in "cleau-up doses or in maintenance doses in both vehicle fuel tanks and larger storage tanks. It is expensive, but you only use a few ounces at a time so the bottle lasts a long time.

ANOTHER CAUSE FOR REDUCED POWER: A few months ago I again sensed reduced power. Changing the primary filter did not help. My mechanic found the engine had de-rated due to a CAPS pump failure.

So, if filters don't help ... now you know a couple of other possibilities, neither one fun or inexpensive!!

[Arizona Anni]

Thanks for sharing your insight. Mine is also shooting black smoke. Will start with filters and see where we go. Will update when we figure it out.