Won’t start after changing fuel filters

Topic: Won’t start after changing fuel filters (Read 3242 times) previous topic - next topic

Re: Won’t start after changing fuel filters

Reply #50 – December 01, 2023, 01:16:58 pm

Quote from: dbennett9 – November 30, 2023, 06:34:25 pm

I finally got the coach to Cummins in Austin on Tuesday. They diagnosed it on Wednesday and the verdict is the fuel pump died. So they are ordering a fuel pump. You don't even want to know what it will cost.

Dave do they have any idea what caused the failure

Re: Won’t start after changing fuel filters

Reply #51 – December 01, 2023, 02:29:43 pm

I asked that. I wanted to know if there was anything I might have done that caused it or anything that might have prevented it, but the service person said that they just fail sometimes. He said that things like not driving it a lot or bad fuel would not cause the pump to fail. Apparently it is just the luck of the draw. Like they used to say on Hee-Haw, if it weren't for bad luck I'd have no luck at all.

Re: Won’t start after changing fuel filters

Reply #52 – December 01, 2023, 02:41:38 pm

That's exactly why I reccomeded to use some diesel kleen,just got off their site,it is used to lubricate the fuel system and the fuel pumps,for the guy to say they just fail sounds like a lame answer.

Re: Won’t start after changing fuel filters

Reply #53 – December 01, 2023, 02:54:48 pm

Sorry I didn't see this when you had the problem.
Our build is only 15 coaches after yours. We also have an ISL400 with CAPS.

We had a similar problem and it ended up being a bad Injector Control Valve, p/n 4089662RX
Lost power stuck roadside - Page 2

Re: Won’t start after changing fuel filters

Reply #54 – December 01, 2023, 09:05:01 pm

Quote from: John44 – December 01, 2023, 02:41:38 pm

That's exactly why I reccomeded to use some diesel kleen,just got off their site,it is used to lubricate the fuel system and the fuel pumps,for the guy to say they just fail sounds like a lame answer.

I use Diesel Klein with every tank of fuel, but that didn't save me. Sometimes things do just fail.

Re: Won’t start after changing fuel filters

Reply #55 – December 01, 2023, 09:10:59 pm

Quote from: bpal – December 01, 2023, 02:54:48 pm

Sorry I didn't see this when you had the problem.
Our build is only 15 coaches after yours. We also have an ISL400 with CAPS.

We had a similar problem and it ended up being a bad Injector Control Valve, p/n 4089662RX
Lost power stuck roadside - Page 2

I did tested the electrical function of the injector control valve myself, and it appeared to be OK. Cummins also tested it and it passed. They said the pump is not building enough pressure. If I understand correctly, and I plan on double checking this on Monday, they are replacing the entire assembly, which includes the injector control valve. I hope I have that right because I wouldn't want to have the old injector control valve since my understanding is they fail more often than the pump.

Re: Won’t start after changing fuel filters

Reply #56 – December 01, 2023, 09:23:20 pm

Have they test the pressure relief valve a little blow by from this valve would cause a low fuel rail pressue

Re: Won’t start after changing fuel filters

Reply #57 – December 01, 2023, 10:49:41 pm

Quote from: wolfe10 – November 30, 2023, 06:46:42 pm

Assuming this is a CAPS fuel system (depends on when engine was manufactured):

Fuel pump or CAPS pump? One is $$, the other $$$$$$$.

If fuel pump, a known issue, particularly for leaks (fuel out and AIR IN). Not a big job to replace.

Beginning in 1998, Cummins introduced the ISC based off the earlier mechanical 8.3 C-series engine. The original ISC engine featured a Cummins Accumulator Pump System (CAPS).

This CAPS pump was a computer controlled injection pump,with individual fuel lines to each injector.

In 2003 the HPCR system was introduced.

Cummins Accumulator Pump System (CAPS) fuel injection pump for Cummins 6 cylinder C series engines where used in heavy duty on-road, agricultural applications and many Motor-home applications.

CAPS systems had many failures due to air leaks on the Lift pumps. CAPS pumps then fail due to lack of lubrication costing in the 4K and up range.
According to his signature this is a 2004. he shouldnt have the CAPS system.

Re: Won’t start after changing fuel filters

Reply #58 – December 01, 2023, 10:52:39 pm

The common rail pumps seem to last better and cost lessBUTfuel injectors fail sooner and are real grossly expensive. If I owned a caps system i would be looking to spend more money to delete the required draw on the pump inlet and install some sort of positive feed like a FASS system. I feel it would be better and even plan to install on our ISM coach eventually. Other benefits are air free fuel and longer injector life. Cooler ECM, Fuel polishing and better filtration . Hate to see anyone have to go thru these issues

Won't start after changing fuel filters

Re: Won’t start after changing fuel filters

Reply #59 – December 01, 2023, 10:59:22 pm

Quote from: dsd – December 01, 2023, 10:52:39 pm

The common rail pumps seem to last better and cost lessBUTfuel injectors fail sooner and are real grossly expensive. If I owned a caps system i would be looking to spend more money to delete the required draw on the pump inlet and install some sort of positive feed like a FASS system. I feel it would be better and even plan to install on our ISM coach eventually. Other benefits are air free fuel and longer injector life. Cooler ECM, Fuel polishing and better filtration . Hate to see anyone have to go thru these issues

And....the very reason I did away with my problem prone lift pump and installed the full FASS system on ours. Unless you keep and eye on your lift pump every time you take it out, you just never know when it can start to leak and suck air. Also made our coach run much smoother, and a decent performance /economy upgrade too.

Re: Won’t start after changing fuel filters

Reply #60 – December 01, 2023, 11:36:58 pm

CAPS systems had many failures due to air leaks on the Lift pumps. CAPS pumps then fail due to lack of lubrication costing in the 4K and up range.
According to his signature this is a 2004. he shouldnt have the CAPS system.
[/quote]
This is the pump that Cummins lists for my coach's engine serial number: 142-075-0003 by D&W - D&W Remanufactured Cummins Fuel Pump CAPS

I used the link to Find-it Parts because they have a description that identifies it as a CAPS pump, but the part number is from Cummins Parts. Maybe they continued using it after the newer system was introduced, or maybe Foretravel still had older engines on hand.

Re: Won’t start after changing fuel filters

Reply #61 – December 01, 2023, 11:50:48 pm

IIRC, these pumps are modular consisting of 5 major parts. Sometimes it's not necessary to replace the entire pump,

Re: Won’t start after changing fuel filters

Reply #62 – December 01, 2023, 11:54:48 pm

yep, thats a CAPS pump. Guess you must have a left over 2002 Engine in a 2004 coach.

If it were my coach, and I was going to have to spend that much on an injection pump, I would also do away with the leak prone Lift pump as part of the work. Even new out of the box lift pumps have a tendency to start leaking due to the fact they still use a Nitrile Diaphram. The modern diesel takes its toll on Nitrile. Once the pumps starts to weep fuel, it is also sucking air and thats what causes the CAPS pump to fail. I preferred to not want to have to check it daily, and maybe end up where you are at. I knew this when I bought the coach and planned for the upgrade soon after purchase.

I personally have had great service out of my FASS Titanium system and did a full write up on it here.
You dont have to install the full FASS system unless you want to, you could just do the pump. But glad I bought the full system. Another company called AIRDOG sells a similar.

My Fass writeup
FASS fuel system install upgrade

Re: Won’t start after changing fuel filters

Reply #63 – December 02, 2023, 08:22:18 am

Often, newer design engines (mainly done to meet ever-stiffer emission requirements) are more expensive than the older ones.

I don't know if there was a price jump between CAPS and the HPCR engines, but likely.

That was certainly true as after-treatment systems were needed to meet the new standards. Big $$$ increase.

So, what all manufacturers (OTR truck as well as RV) is buy a huge quantity of the older/less expensive engines.

Remember, it is actual date of engine manufacture, not year of coach that determines what emission standards the vehicle must meet.

So, by reading the fine print in the EPA rules, the manufacturers saved $$$ and it was pretty common for the engine to be older than the vehicle they were installed in.

Re: Won’t start after changing fuel filters

Reply #64 – December 03, 2023, 11:46:56 pm

Quote from: bbeane – December 01, 2023, 11:50:48 pm

IIRC, these pumps are modular consisting of 5 major parts. Sometimes it's not necessary to replace the entire pump,

I want the entire assembly replaced. With labor costing what it does, I would rather spend more on the entire assembly than risk another part of it failing down the road.

Re: Won’t start after changing fuel filters

Reply #65 – December 04, 2023, 11:57:55 am

Quote from: dbennett9 – December 03, 2023, 11:46:56 pm

I want the entire assembly replaced. With labor costing what it does, I would rather spend more on the entire assembly than risk another part of it failing down the road.

BBeane is correct, but agree with your view.
Just be sure and ALSO address the Lift pump issue, or you will be doing it again. These pumps, DONT just up and fail. Its caused by air entering the fuel path at the lift pump. If you start searching this in great detail you will see many, many cases of this failure for this reason. Even Cummins techs nationwide will tell you, CAPS was not a proud moment for Cummins for this very reason. Just about any tech out there will also tell you, to avoid the problem, do away with the lift pump and go with a more reliable low pressure fed fuel delivery system. CAPS injector pump is not the weak link, the lift pump and its failing diaphram is.

If you truly have a good knowledgeable Diesel repair shop, they should be fully aware of this problem and be more than willing to also assist with a pump upgrade by installing a FASS or Airdog system.

Re: Won’t start after changing fuel filters

Reply #66 – December 04, 2023, 05:43:12 pm

Quote from: dbennett9 – December 03, 2023, 11:46:56 pm

I want the entire assembly replaced. With labor costing what it does, I would rather spend more on the entire assembly than risk another part of it failing down the road.

I had my ICV on my pump replaced several years ago at Cummins. But my pump failed last year and had to replace the whole pump with a Cummins rebuilt pump. I think the pump was around $4600.

Mark

Re: Won’t start after changing fuel filters

Reply #67 – December 25, 2023, 12:26:53 am

I am updating this in case anyone else has a similar problem, as they might know better what to check based on our experience. As I posted earlier, the problem was the fuel pump was not building pressure. Cummins did replace the entire fuel pump assembly, which includes the injector control valve. They also replaced the transient suppressor; I asked about that because I had read about issues with it, and they said it is always replaced with the fuel pump. However, once the new fuel pump was installed the engine started and ran but ran very rough. They were getting a code that indicated an ECM issue, so they tried recalibrating the ECM. The engine still ran rough, so they tried a test ECM, which fixed the problem. They then replaced the ECM.

I don't know exactly why the ECM failed along with the fuel pump, but I do have a theory based on what I have read. A failing fuel pump can apparently send voltage spikes back to the ECM; that is what the transient suppressor is supposed to prevent. So I think the transient suppressor was probably bad, and when the fuel pump died it damaged the ECM. If that is the case, it was a perfect storm of events. I hope this doesn't happen to anyone else because it is a very expensive issue. The entire repair was in excess of 14K. And that does not include fixing the damage done by the tow driver who did not properly secure the drive shaft after he disconnected it. That repair includes a new pinion yoke, driveshaft, and u joints.

Re: Won’t start after changing fuel filters

Reply #68 – December 25, 2023, 02:25:53 am

Terrified to hear about all this. So glad you have it resolved.

Re: Won’t start after changing fuel filters

Reply #69 – December 25, 2023, 01:02:53 pm

Wow, glad you finally got it resolved, and surely a very costly failure......did you have your lift pump thoroughly checked out or replaced as well?

Re: Won’t start after changing fuel filters

Reply #70 – December 26, 2023, 01:34:09 pm

[I removed a couple of off-topic, unhelpful posts. Michelle]

Re: Won’t start after changing fuel filters

Reply #71 – December 26, 2023, 11:32:22 pm

Quote from: mkc1962 – December 25, 2023, 01:02:53 pm

Wow, glad you finally got it resolved, and surely a very costly failure......did you have your lift pump thoroughly checked out or replaced as well?

I spoke to the Cummins service advisor about the lift pump. He said he was not aware of lift pump issues causing the fuel pump to fail. He also said they saw no sign that the lift pump was leaking, so it should not be able to suck air. I plan to look into the lift pump more once I get the drive train fully repaired—I still need to get the new driveshaft and install it. It is on order and should come in this week.

Re: Won’t start after changing fuel filters

Reply #72 – December 27, 2023, 08:34:14 am

Quote from: dbennett9 – December 26, 2023, 11:32:22 pm

I spoke to the Cummins service advisor about the lift pump. He said he was not aware of lift pump issues causing the fuel pump to fail.

Hard to believe a Cummins service advisor would say that as that is a very common failure issue on that fuel system-- sucking air at the lift pump with the engine running.

Re: Won’t start after changing fuel filters

Reply #73 – December 27, 2023, 11:14:05 am

Brett is 150% spot on with his comment. lift pumps sucking air and causing Injection pump failures, is a well documented Cummins issue that any reputable Cummins shop should know about. You must have been dealing with a young inexperienced service advisor. I talked with over 3 myself back before buying our coach and afterwards, as well as a few older techs since that time, All of them stated the CAPS years is a time Cummins is not proud of, but brings them lots of revenue from time to time. I am glad you got your issue resolved, but in your best interest, you might want to read more on the subject and know that even brand new pumps eventually fail, start to leak, and in turn will suck air. Keep in mind, Air can also come from other places, Like loose fittings, old fuel lines, etc. As your coach is soon to be 20 years old, if not already done so, fuel line replacement is wise. Many of us that have done them have found cracks in fuel lines or loose fittings. If I was just on the receiving end of a very costly CAPS failure, I would only run it to get it home, or to the the next shop that is knowledgeable on the subject, and can do a system upgrade, to include new fuel lines.

Here is the why the pumps fail.
Old and even brand new lift pumps use a BunaN/Nitrile diaphragm at their core. The modern diesel fuel is missing key lubricant qualities that makes it not as compatible with BunaN as it used to be. It eventually causes the rubber to get firm and the gasket to lightly shrink, which in turn allows that gasket to leak. All the tightening in the world will not stop the leak, only make it leak a bit less. Any leak is sucking air. Your lift pump only runs for 30 seconds at the beginning of the start cycle, then the CAPS pump is forced to suck that fuel all the way from the tank. ANY air entering the system is causing the caps pump to work harder, lose lubrication and cooling to the caps system, which ultimately can lead to a very costly failure. Any seasoned reputable Cummins tech would tell you (if asked) that to keep positive pressure to the CAPS pumps is definitely better than the OE design.

I was aware of this issue with the 8.3's of our vintage, and kept it in the back of my mind as I shopped for a coach. But ultimately I did buy one that had it. But at the same time was aware of the upgrade, and said the minute I see any sort of leakage of fuel I was going to do that upgrade. Sure enough after a few short trips of ownership it did so. Any 20+ year old lift pump is apt to do it at any minute. When it did, I installed that upgrade, along with all new fuel lines, as they too can be a cause of air into the system, and hopefully never have to worry about this issue again....we have enough issues to worry about driving 20+ year old coaches..
FYI the basic FASS System is not much more cost than a new Lift pump, but is a bit more complicated to install.

Re: Won’t start after changing fuel filters

Reply #74 – December 27, 2023, 11:33:35 am

Another reason for using fuel additives.

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