As many readers here know, we have been having dirty fuel problems. We bought our Newmar in 2009, it had sat 9 years in dry storage I had only 8700 miles on it. We worked our way thru. the wake up period with new hoses belts, and tires, and were really happy with the coach. 2010 we were returning from a trip to NY, and the coach started to loose power, and would quit, we would wait 15-20 minutes and it would start and run but at a lower speed than normal. I changed fuel filters and it returned to normal, I changed filters 2 more times from N.M. to Wa. all were contaminated with a black debris looking like soot from a chimney. It's a had particulate matter and fells like black sand.I was totally convinced that we had loaded a bad / dirty fuel. Once at home, I drained all fuel, removed the fuel tank, hoses, filters, and associated units flushed and cleaned them, replaced all the equipment. and it has run great until this month. we now have 41k on the cummins. we find the whole fuel system is contaminated again. Same stuff, same symptoms, and same Fault codes of low fuel pressure. I have now replaced both fuel filters, re-set the fault codes and the coach runs great again. But where in the world is this stuff coming from?I believe the Cummins 8.3 ISC 350 horse is producing the carbon, and returning it to the tank, which is clogging the filters. I have asked Cummins for assistance but have not heard from them yet.

path1 wrote:You run any type of biocide?I do, but this not I repeat this is not Algae. Algae is a slime that clogged filters, you need water to grow Algae, there has never been any water show up in my filters, this is hard particulate carbon that feels like sand. I've had under a microscope, it is carbon particles. Not Algae.

I drove a 1978 GMC Buffalo to Mexico several years ago for a church group and it had been sitting for several years with a 1/2 tank of fuel. I checked it out, drove it to a mech to have it checked further and got fuel on the way back to park it. Loaded the kids and gear and headed out. Got fuel in Redding and added some fuel system cleaner and headed out the next morning. After stopping at Cottonwillow rest area,it started up fine,but as soon as we started to move, it stopped. We got it towed in to Bakersfield at 4 AM and got a mechanic from Valley out on a Sunday AM to fix it. It turns out that there was the type of algae that grows in diesel plugging the fuel line and both filters. He changed thefilters and blew out the fuel line from both ends and told me to hot fuel it for the next couple of tanks. Gave us a couple of extra filters and I hot fueled it there in Bakersfield and just before we went into Mexico and didn't have a bit of trouble.He also told me that you always want to park it with a full tank of fuel to stay away from that problem.

What you describe is like the carbon in a vapor canister.Miles

I have restored several old Classic vehicles and old fuel tanks can be a problem. Most fuel tanks are coated/plated to prevent rust but that only lasts for so long. Once rust starts to form in a fuel tank, just flushing it out WILL NOT solve the problem. "Rusticles" will continue to form in the tank, even if it is full, unless it is flushed and the interior is coated/sealed with one of the numerous products on the market for this purpose. These "rusticles" are very fine particles and they will clog most filters and can get past most filters that are not designed for fuel injected vehicles.

Continued dirty fuel problems. | Good Sam Community

donkeydew
Explorer
Jun 05, 2015
Tom/Barb wrote:
Comments on using one of These?

i have this on my beaver and it has never given any problem but finding filters.on line or a good marina solved this
Ivylog
Explorer III
Jun 05, 2015
"maybe a blown copper gasket"
Tom, look at the injector lines at the injectors, there is not a return fuel line... only one high pressure line to each injector.
Tom_Barb
Explorer
Jun 05, 2015
buta4 wrote:
Perhaps consider filter systems that the boating industry uses for their diesel engines. Besides the engine final filter they use one or to filters from 10 down to 2 microns, for example.

If there's room in your engine compartment.

That is exactly what the reference above is "Racor" filters are industry's best filter system. I am trying to understand the size I need. the smallest is about 15 GPM. at 2 micron. but the aircraft industry only uses a 3 micron, I think that's a little over kill.

I'd rather fix the cause, during a conversation with Cummins, there maybe a blown copper gasket under one or more of the injectors that is allowing soot from combustion to be returned to the tank as return fuel.
buta4
Explorer
Jun 04, 2015
Perhaps consider filter systems that the boating industry uses for their diesel engines. Besides the engine final filter they use one or to filters from 10 down to 2 microns, for example.

If there's room in your engine compartment.
path1
Explorer
Jun 04, 2015
That's why I asked if your running a biocide to eliminate the easy to fix algae problem. And all fuel hoses are fuel rated?

IMO soot is getting into fuel system.

Fuel problems equals big bucks. Either at injection pump, injectors, caps system somewhere. Keep testing to confirm before spending big bucks on those items.
Tom_Barb
Explorer
Jun 04, 2015
Comments on using one of These?
Tom_Barb
Explorer
Jun 04, 2015
Ivylog wrote:
Tom, sorry to hear you are still having this problem with carbon in your fuel (folks it's not algae or the tank coating coming off... read his 2011 posts). I would add this $57, 5 micron filter to the return fuel line at the tank. I've used them to filter 5+ year old diesel before using. Should take several years before needing a new cartridge and it should keep the fuel in the tank from getting dirty.

A plastic water filter?? I'm a little worried about that with hot diesel coming from the engine.
mabynack
Explorer II
Jun 04, 2015
rgatijnet1 wrote:
I have restored several old Classic vehicles and old fuel tanks can be a problem. Most fuel tanks are coated/plated to prevent rust but that only lasts for so long. Once rust starts to form in a fuel tank, just flushing it out WILL NOT solve the problem. "Rusticles" will continue to form in the tank, even if it is full, unless it is flushed and the interior is coated/sealed with one of the numerous products on the market for this purpose. These "rusticles" are very fine particles and they will clog most filters and can get past most filters that are not designed for fuel injected vehicles.

X2

Ford had a problem with this about 10 years ago. They used a coating on the inside of the fuel tank that would break down and peel off. Once it starts it's hard to get rid of without replacing the tank or sandblasting the old coating off and resealing the tank.
Ivylog
Explorer III
Jun 04, 2015
Tom, sorry to hear you are still having this problem with carbon in your fuel (folks it's not algae or the tank coating coming off... read his 2011 posts). I would add this $57, 5 micron filter to the return fuel line at the tank. I've used them to filter 5+ year old diesel before using. Should take several years before needing a new cartridge and it should keep the fuel in the tank from getting dirty.
Tom_Barb
Explorer
Jun 04, 2015
rgatijnet1 wrote:
Page two, paragraph four, seems to talk about your problem. Diesel fuel problems

Another link about fuel filter problems. Diesel fuel

Reading both of those references the answer is a better filter and more often element changes.

I'm looking at Racor filters, trying to decide which one to replace the Chassis filter with. They have an accessory that will indicate when a element change is needed.

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