Continued dirty fuel problems.

[Tom_Barb]

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.

[donkeydew]

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]

"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]

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]

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]

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]

Comments on using one of These?

[Tom_Barb]

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]

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]

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]

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.

[rgatijnet1]

Page two, paragraph four, seems to talk about your problem. Diesel fuel problems

Another link about fuel filter problems. Diesel fuel

[wolfe10]

Could be the fuel lines breaking down. Pull one where you have access and look carefully at the inside.

[Tom_Barb]

Son of Norway wrote:
What you describe is like the carbon in a vapor canister.

Miles

Exactly, but we don't have any of them.

The fuel I get from the filter bowls looks like I washed out the tail pipe with it. or what you'd find at the bottom of and old oil pan. it is absolutely black.

[Tom_Barb]

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.

Lab tests on this says it is carbon, not iron oxide. (that is what rust is)