Cummins El Paso

moisheh wrote:
Access is dependent on your unit side V rear rad. On mine it is very easy to open the hatch. It is not in the floor under the bed or in the closet. I opened it up but the mechanic was able to climb into the engine compartment and reach. You need a skinny mechanic. There is one other possibility for your problem. When they removed the filters were they full? Are the thick o rings installed? On mine there was one filter mounting flange that was not machined straight. Don't know how it worked for 7 years. BTW there is a new improved filter . I am sick today so cannot get it but hopefully will find the # tomorrow. If the only code is that 559 Cummins has a whole list of things to check or replace. But I would suggest to just do the things I did. Anything else is going to be mega bucks. Do you have those plastic fuel lines? Could one of them have rubbed on something and made a pin hole? Please keep us posted. ON EDIT: What brand of filter are you using?

I have side radiator but access on the fuel rail side of the engine looks tight. To access top of engine, I have to remove the two wardrobe doors (have to remove bottom track to remove access panel in floor) and raise the bed.

Whenever I have removed my filters, they were full of fuel. My primary has 1" threaded stud and that filter uses the center rubber o ring. My secondary filter head has 7/8" stud and it is pretty short and there is no center o ring. If you try to put the o ring on that stud, there is not enough thread left to get the filter on.

The large diameter line from the tank to the inlet of the primary filter head appears to be a hard plastic. The line out of the primary and both lines on the secondary are some sort of nylon mesh wrapped lines.

I am under the impression it cannot be a bad lift pump since on our engine the lift pump only runs briefly, then goes into a bypass mode and a mechanical pump takes over.

I do remember my local Cummins shop telling me the diagnostic time and effort related to the 559 code was lengthy and expensive. I certainly don't want to tell the mechanic what to do but I do plan share your experience with him. I will be at an independent shop so not sure if they have the full access to all things related to Cummins.

Access is dependent on your unit side V rear rad. On mine it is very easy to open the hatch. It is not in the floor under the bed or in the closet. I opened it up but the mechanic was able to climb into the engine compartment and reach. You need a skinny mechanic. There is one other possibility for your problem. When they removed the filters were they full? Are the thick o rings installed? On mine there was one filter mounting flange that was not machined straight. Don't know how it worked for 7 years. BTW there is a new improved filter . I am sick today so cannot get it but hopefully will find the # tomorrow. If the only code is that 559 Cummins has a whole list of things to check or replace. But I would suggest to just do the things I did. Anything else is going to be mega bucks. Do you have those plastic fuel lines? Could one of them have rubbed on something and made a pin hole? Please keep us posted. ON EDIT: What brand of filter are you using?

moisheh wrote:
Fuel problems

I had a similar problem and a Cummins specialist could not fix the problem. Did some googling and 2 or 3 other ISL owners had the same problem. It was the fuel rail pressure switch and sensor. Even though they were faulty it did not show up on a test. Parts are about $250.00 . Were you getting a 559 code? You might have to join IRV2 to read the above link.

Moisheh

I get code 157 on my Silverleaf which is the same as Cummins 559 code. I changed my filters yesterday and only got from San Antonio to Kerrville, TX before it reared its head. 30 mph up the grades is no fun.

I have an appointment with LeMeilleur's RV/Truck repair in Kerrville early next week. They say they think they know the likely cause but will need to do the diagnostics. I will share your info with them.

Do you know if you can get to the rail pressure switch and sensor without getting to the top of the engine? Just curious if we need to get stuff in bedroom out of the way so they can work from top or bottom.

I'd replace the whole filter to a Raycor

230R10 would be the one I'd use

Fuel problems

I had a similar problem and a Cummins specialist could not fix the problem. Did some googling and 2 or 3 other ISL owners had the same problem. It was the fuel rail pressure switch and sensor. Even though they were faulty it did not show up on a test. Parts are about $250.00 . Were you getting a 559 code? You might have to join IRV2 to read the above link.

Moisheh

smlranger wrote:

I may see if the folks at Cummins El Paso will replace my secondary filter head with the head with 1" stud which gives me a lot of filter options.

Fuel system terminology-- fuel system from fuel tank:

Tank

PRIMARY fuel filter/water separator. Typically 10-30 micron element

Lift pump on many applications.

SECONDARY fuel filter. Depending on engine manufacturer's specs, but generally 2-5 micron.

Engine injection system

Tom/Barb wrote:

smlranger wrote:

wolfe10 wrote:
When you changed the fuel filters-- what did you find?

Fuel poured out of any of my filters has looked absolutely fine. I have not cut any filter open yet. I always store the coach with a full fuel tank and I have been treating the fuel with BioBor (just in case) for the past year.

My issue this trip started after getting 50 gallons of fuel at a very busy Pilot and after driving over some really rough road in LA. That led me to suspect something stirred up in the tank.

I talked to my local Cummins shop in VA and they told me that some folks had reported similar issues and had switched their secondary filter to a 10 micron filter and the problem went away. My secondary fuel filter head has 7/8" stud and I have not yet located any 10 micron filters that will fit that head. My Fleetguard FF5636 is 2 micron. My primary filter is 10 micron. A friend with an ISC read a Cummins tech bulletin about fuel starvation on ISC's with 2 micron filters and recommended changing to 10 micron. He has done that and his similar issue went away.

I do not have any issue with oil consumption. I have never had to add oil between annual service except last year when I had a leaking valve cover and gear cover. That was fixed at Cummins.

When I had the coach at my local Cummins shop last year for the oil leaks, they were aware of the previous issue I had with low fuel pressure. They said they checked over everything and found no obvious issues. They ran the coach on their dyno for 3 hours and it ran fine.

I have never had any overheating issues. My coolant temp runs 186-188 until hard pulls when it may reach 195 for brief periods.

No chips. This is a bone stock 425ISL clean diesel (DPF).

In that case, forget the engine contaminating the fuel system, (our problems are not the same)
The 2 micron filters clog very easy. 2 micron is .0.00007874015748031496 inches. that is 98% of the particles bigger than that will be trapped. Many have gone to a 10 micron, and have no problems.

I have been browsing the net.... Baldwin, Wix, Donaldson, Fleetguard and I have not been able to find any 10 micron fuel filter that has the 7/8" stud opening. The best I've found is a Donaldson rated at 5 micron. I may see if the folks at Cummins El Paso will replace my secondary filter head with the head with 1" stud which gives me a lot of filter options.

RayChez wrote:
I had a problem like that and it was a air filter that needed changing out. And how is your Turbo pressure?

A clogged air filter will cause a major loss of power, but not a low fuel pressure event.

I had a problem like that and it was a air filter that needed changing out. And how is your Turbo pressure?

Can't help with your problem but as full-timers, we've used Cummins facilities for maintenance in many states. I would trust them especially if you give them a thorough background on your motorhome issues. I'd recommend calling to set up an appt. when you can judge when you'd get there. Tell them you're traveling. Then you won't have a long wait. Good luck!