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Topic: Intermittent Stop Engine Light (Read 3431 times) previous topic - next topic

Intermittent Stop Engine Light

One problem solved (actually two counting the leaking fuel filter), another takes its place :o The oil pressure sensor issue is completely solved, but now I have another that is trying to rob me of my equanimity. Fueled up at Sam's Club near Salt Lake yesterday (diesel $2.49.9 per gal) and was feeling good about the 403 mile run from Vegas the day before (no running issues, no annoying check engine lights, all systems go). Shortly after leaving Sam's, I got the dreaded stop engine light and the boost was basically turned off. The stop engine light only flashed for a split second and then went away. Rinse and repeat Ad Nauseum. We got off the freeway a couple of times where I would check things over and cycle the switch on the chassis battery disconnect. It would get back on the expressway just fine, boost and all, and then shortly thereafter it would start happening again. The diagnostics log on the VMSPC wasn't all that helpful giving a number and then "Bad Program" and sometimes unknown component.

Well, I once experienced a similar issue that turned out to be something nasty growing in the fuel system which seemed to be solved with a primary fuel filter change and doeses of biocide at each fill up. We filled up at the Sam's Club in Murrieta Hot Springs on the way to Las Vegas (being kind of punchy from the process of getting ready to leave, I neglected the biocide :headwall: Anyway, I carry a couple of spare primary filters and the fuel that I drained from the leaking secondary looked clean before I changed the filter, so I did a quick change of the primary (should :facepalm:  have changed it when I changed the secondary!). The one that was on there was the Baldwin which didn't have a clear bowl, but it does of course have a drain. Well, draining it revealed that was definitely contaminated! Okay, I got out my new filter and the clean clear plastic bowl and installed it. Unfortunately, I didn't have any clean diesel to prime it with, so I just used the key on for thirty seconds and then off again to cycle the electronic lift pump that the ISC's have. I thought that should work to purge the air, as Cummins says specifically not to prime the secondary filter but to use the lift pump to fill it, or it might damage the fuel injection pump. Anyway, that seemed to work for a little while, but soon it started happening again, though maybe not as severely. I stopped multiple times, drained a bit of fuel into a clean glass jar from the primary fuel filter, and it looked fine.
I have one more spare primary, but I thought it might possibly be some air (listed as a possibility by the Cummins Trouble Shooting manual) so I pulled out my Cummins InLine 5 interface a tried to fire up my Toughbook with the Cummins InSite software (which I bought as a package on eBay a couple of years ago). After a couple of frustrating hours of trying to get the software to work (don't ask!) I finally managed to get it working. With this, I was able to get some more specific information about the fault codes. It involves the CAPS fuel injection pump giving an over pumping indication which cause a derating. Following that troubleshooting tree, the first items are fuel contamination, air in the line, and possible incompatible fuels that don't meet the Cummins specification. I suspect I got one or maybe two loads of crap diesel from Sam's Club. To try and eliminate the air in the line scenario as suggested by the trouble shooting tree, I used the software tools to run the lift pump override test from the ECM test menu of the InSite software. With the key on, it just runs the lift pump for 60 seconds (engine not running) to cycle the fuel through. I did this 3 times with a minute or so between each test which should help purge any air. I also ran the click test for the CAPS pump and that passed normally (this tests the valve and two solenoids that are part of the CAPS pump). I considered putting in my last primary filter, but the fuel coming out of the clear bowl of the primary was still looking clean.
Hoping that the air purge would do the trick, we hit the road. Everything looked normal for the first ten minutes, and then... well you know the rest :headwall: Well, it was a bit better overall as the boost kept working normally, but any prolonged pull under moderate to high load, would flash the stop engine light and in a couple of cases, it would last until the grade leveled off. Naturally I was not pushing it mostly keeping under 60. Only 130 miles total today and it almost feels like I did it Fred Flintstone style. Tomorrow, I will try to have a fresh look and we will try and make it to a Kenworth Shop, to at least stock up on a bunch of fuel filters and possibly to have them look at it. Worst case scenario, a bad CAPS injection pump (I really, really don't want to go there!). Best case, and most likely in my mind is bad fuel. I will stop at the very next truck stop and see what kind of magic juice they have for fuel treatment, so feel free to recommend your favorites! Thanks for slogging through this rather long post, but I doubt I will be the last to experience the dreaded bad fuel issue, so maybe our outcome, whatever it is might help the next guy or gal. I am to tired to do anymore searching tonight, so if anyone wants to link a thread you think might be helpful or relevant, pleas do!
Don

Re: Intermittent Stop Engine Light

Reply #1 –
Good morning, Don.  When I recently had our oil changed at the local Cummins dealer, I asked about additives.  He pointed out that Cummins recommends Power Services brand.  Power Services products are available at Wal-Mart.  The PS Clear-Diesel Fuel and Tank Cleaner might be something to consider.

Re: Intermittent Stop Engine Light

Reply #3 –
Quote from: Don & Tys (AKA acousticart) –
I stopped multiple times, drained a bit of fuel into a clean glass jar from the primary fuel filter, and it looked fine.
I have one more spare primary, but I thought it might possibly be some air (listed as a possibility by the Cummins Trouble Shooting manual) so I pulled out my Cummins InLine 5 interface a tried to fire up my Toughbook with the Cummins InSite software (which I bought as a package on eBay a couple of years ago). After a couple of frustrating hours of trying to get the software to work (don't ask!) I finally managed to get it working. With this, I was able to get some more specific information about the fault codes. It involves the CAPS fuel injection pump giving an over pumping indication which cause a derating. Following that troubleshooting tree, the first items are fuel contamination, air in the line, and possible incompatible fuels that don't meet the Cummins specification.

Hoping that the air purge would do the trick, we hit the road. Everything looked normal for the first ten minutes, and then... well you know the rest

Don - are your fuel lines original?  ...  Noting that you have a 1999 and many folks with a 2001 going back to the 1996's have had to replace their fuel lines due to cracking/air...

Re: Intermittent Stop Engine Light

Reply #4 –
Thanks for mentioning that Michelle! In my fog last night I forgot to mention that the fuel lines (all of them!) were changed at Foretravel in November of 2013. One of the first things to be considered with fuel problems on these vintage coaches!
Don
Quote from: Michelle –
Don - are your fuel lines original?  ...  Noting that you have a 1999 and many folks with a 2001 going back to the 1996's have had to replace their fuel lines due to cracking/air...

Re: Intermittent Stop Engine Light

Reply #5 –
I use the optilube also and the biocide

Re: Intermittent Stop Engine Light

Reply #6 –
Don, if they start talking about replacing the CAPS pump make sure it is the
problem. I replaced mine ( leaking) 2 years ago they are pricey.

Re: Intermittent Stop Engine Light

Reply #7 –
Regarding the lubricity enhancers... found an interesting test linked here;
Lubricity Additive Study Results - Diesel Place : Chevrolet and GMC Diesel...
This was linked from the Optilube site but doesn't appear to have any ties to the company. Some of the additives appear to decrease the lubricity of the USLD. Among them was ValvTect! I have been using ValvTect's Biocide (not the same stuff as the lubricity additive, but it does make me want to choose a different brand for algae assassination!). Now to research the biocides...
Don

Re: Intermittent Stop Engine Light

Reply #8 –
Don,

Sorry for continued problems.  We have never had to deal with these things (knock on wood).  I know in the past Brett W. has often mentioned a "fuel polishing" process to deal with contaminated diesel.  If you decide this current problem is caused by "dirty" fuel, I am wondering if there are any kind "fuel polishing" services available along your route, perhaps at truck stops or diesel fuel suppliers. If feasible, seems like getting the whole tank of fuel cleaned/filtered/treated all at once would be better than having to stop every 100 miles for the next week to change out filters.

Re: Intermittent Stop Engine Light

Reply #9 –
When I first saw which area the leak was coming from, that was my worst fear, but that leak proved to be the filter (the one mounted on the engine near the CAPS pump). I think fuel contamination is far more likely, but some of that may be just my fervent hope. However, I know it is possible that the CAPS pump itself could be the culprit until proven otherwise. If you don't mind sharing, who did yours and how much did it cost? Go ahead, I am sitting down... :'(
Don
Quote from: bbeane –
Don, if they start talking about replacing the CAPS pump make sure it is the
problem. I replaced mine ( leaking) 2 years ago they are pricey.

Re: Intermittent Stop Engine Light

Reply #10 –
Algae is either the problem or it's not. If you find algae in the primary filter, then it's the problem. Going through several filters usually does the job. If you can see down in the tank (you can on our U300), use a bright LED light and a mirror to look at the bottom of the tank once the tank is low. You can use the HWH to lean the coach to one side and then using a pump/hose combination, remove the algae and water from the bottom. The LEDs/mirror will make sure there is nothing stuck on the walls of the tank.

I installed a pressure gauge on the outlet of the secondary filter. Shows pressure after all the filters and lift pump at idle. You would need a camera to see the pressure under load (or a gauge with a sender). Cummins lift pumps DO have occasional problems.

After fueling and while the engine is idling, check the see through bowl at the bottom of the primary filter (if you have one). If fuel contamination is not the problem, check the lift pump. Good article below.

CAPs injection pumps had a terrible reputation early on. They have improved since then but still very expensive to replace. Some go with the super reliable Bosch inline pumps but that's expensive too as other components have to be replaced also. Low fuel pressure from a restriction or bad lift pump can damage a CAPs pump. Not a problem with later common rail injection systems.

For those interested in the CAPs symptoms, etc, here is a quote from "Rich" in an article:

"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.
Cummins ISC 8.3 300 Hp Warm engine rough Idle
Some time ago Cummins issued a service bulletin to change the wiring from the old connector and lead that goes to the fuel pressure sensor to a new connector and lead - an upgrade kit was issued for this which included a new connector, three crimp connectors and an instruction sheet.
A lot of time the connectors which are supposed to be sealed upon crimping, fail and the ECM sees the fuel pressure vary during idle hence rough idle and sometimes no starts.
The solution is twofold, one is to clean and inspect every connector (including the big one near the lift pump) and degrease/grease them with the right dielectric grease made for Packard connectors (a lot of techs fail to get that part).
The second is if the upgrade was done, have the tech properly splice (re-solder) the connection and use the correct method to seal the splice.
Also, check the Transient Suppressor. A bad one can damage the injector pump, and if you change the injector pump with out replacing the suppressor; will void the warranty.
Not always the problem, but worth a try!
Replacing the injectors will not solve a bad injector pump problem.
One brand new injector bad?
As the engine warmed up the O-ring on the injector expanded out of spec. and was failing.
To be sure that was the problem, moved the injector to different cylinders to see if the problem followed and it did, but the injector pump proved to be defective also! A relatively new injector pump about 6 months old and exchanged under warranty.
Internal seal-diaphragm can fail and fuel will pass into the oil, making oil! Not good!
Fuel Pressure Specs ISC Series (Minimum)
Low Fuel flow / Pressure can damage the internal electronics. The excess fuel is used to cool the circuits and then returned to the fuel tank.
HPCR CAPS
 Pump 5 psi Cranking 5 psi Minimum
Gear Pump 10 psi Cranking 10 psi Cranking
70 psi @ rated speed"

Pierce




Re: Intermittent Stop Engine Light

Reply #11 –
Don, I had that happen with the stop engine light coming on and off and I tracked it down to my coolant sensor on that metal expansion tank.  It was going bad and as it sent no coolant present in the tank it would set the stop engine off. I got the error message on my silverleaf so I knew where to look

Re: Intermittent Stop Engine Light

Reply #12 –
Don Cummins is the only ones that rebuild those pumps, there are no parts available for aftermarket repair. Cummins rebuilt was 3800.00 + freight, tax and install 5800.00 Freightliner in Decatur Al. Could have done it myself but a little difficult in a camp ground.

Re: Intermittent Stop Engine Light

Reply #15 –
Don & Tys,  So sorry you are having such a big problem.  Hope it resolves quickly.

Your situation helps reinforce our desire to only fill at truck stops, with Flying J/Pilot as first choice, and to carry 3 spares of each of our Isuzu gen & Cummins engine fuel filters, along with a gallon of filter priming diesel fuel (in a red plastic gasoline container). 

We also add a quantity of Power Service's Diesel Kleen with each fill up, and have started adding a container of their Clear-Diesel when storing our motorhome.  We carry several containers of Power Service Diesel 9-1-1 and Bio Kleen, but have never used them.

Good luck and keep us posted.
Barry & Cindy

Re: Intermittent Stop Engine Light

Reply #16 –
Time for one of those fancy USB powered bore scopes...

Re: Intermittent Stop Engine Light

Reply #17 –
Don,

Good biocides are different than fuel system cleaners.

A widely used biocide, particularly in the marine industry is: Biobor Jf Fuel Additives - Products

Been using it since the late 1970's-- sail boats and motorhomes.  Use it any time a "bio-problem" is identified (kill dose) and also when storing diesel for over 2 months in summer or 3 months in winter (maintenance dose).

Re: Intermittent Stop Engine Light

Reply #19 –
Thanks, Chuck.

Brett