Cummins 8.3 diesel cuts out about once every 1000 miles on my newly acquired 1997 U270. I am on a 2700 mile trip delivering the coach from California back to Pennsylvania. Both times, the motorhome was on about a 2% up grade going 56 MPH with the cruise control on. Fuel tanks were about half. After the engine cut out, I stomped on the accelerator...nothing. After waiting about 10 seconds, power was restored. This last cut-out, after the power returned, the coolant gauge read about 100 degrees higher than before.
No idiot lights were displayed.
Other strage behavior:
After the engine cut out, the coolant temperature gauge began to rapidly dance up to 300 degrees and back down to 190 degrees.
Sometimes when the engine is hot and at idle, the oil pressure gauge dances from 20 PSI up to 80 PSI.
Both of the above behaviors subside after a few seconds to a minute, then return to normal for days.
Could the problem be the electric fuel pump near the fuel tank?
Is there a fuel shut-off solenoid?
Is there an ECM / computer in this year of Foretravel?
Other than the above, the engine has run fine for 2000 miles. Plenty of power going up mountain passes. Oil consumption is low and doesn't get dirty too fast. All other fluids are full and normal.
I suspect, as far as the cutting out goes, that it will involve fuel filters and maybe a bit of algae. I would immediately acquire several spare primary fuel filters incase you discover algae, as well as some Biocide. Going up a grade is just where you would expect to find sudden fuel filter related power loss first. I don't think your engine has much in the way of electronics, but on our 99' ISC, I was experiencing a similar symptom that would throw a stop engine light and I would see a code on the VMSPC. When I took the filter off, I was surprised to see some black algae. Changed the filter, added some biocide and no reoccurrence since. Of course, with that age coach, there could be some other more serious issues such as aged fuel lines, lift pump (I assume the C8.3's have such). But fuel filters are the lowest coast, most likely, and easiest things to try first. Even if the filter has been recently changed, a load of bad diesel can clog it quick with algae.
As for the electrical anomalies, first thing to do is check grounds and the connections at both ends. Some good electrical cleaner like Corrosion X applied after cleaning the connections can work wonders.
Don
All rubber fuel lines die with ULSD. Winn fuel filter system vacuum leaks badly. Full tank might help?
My 97 needed the gauge wires crimped tighter then reinstalled on their posts
Not familiar with the 8.3, but symptoms seem electrical. The coach was always in Southern California I doubt there will be an algae problem. The coach was well maintained and you should have the receipts. I talked to John extensively about this coach before I linked it on the Forum. If it hadn't had the window creep I might have bought it myself. Check when the fuel filters were replaced. if over a year ago change proactively.
You probably have the Cummins C8.3 325hp fully mechanical engine with no ECM. Big question is when engine cuts out, do the dash gauges also go off, does dash air fan go off. You must determine what else goes off. It could be ignition solenoid, that give us problems and is often replaced. Does it happen on throttle or just cruise. Throttle and cruise are probably controlled by the King Cruise control box frame mounted on curb rear corner of engine, where it pulls throttle cable. This engine has a fuel shut off solenoid mounted on curb side where it moves a lever to open fuel solenoid when cranking engine, and is held open by ignition circuit. This solenoid could be manually held open with a wire tie and when you want to stop engine cut wire tie. No electric fuel pump on this engine, but there is a mechanical fuel lift pump on curb side that when worn could not be flowing enough fuel to fuel injector pump on curb side. You will figure it out, and this is the most simple of engines that Foretravel has used.
its somethibg electrical, causing the king throttle control to go haywire. More reading:
King Control Throttle and Cruise Control Issues (http://beamalarm.com/Documents/king_control_throttle_and_cruise_control_issues.html)
Tim,
In the 8.3 Mechanical engine, these are all symptoms of a low dash voltage.
The relay that provides power to the dash and systems throughout the coach (located near floor level behind the removable panel in front of the co-pilot's seat) when the ignition is on, may be dropping voltage due to pitted/arced contacts.
On low voltage, the King Cruise and throttle control fails to "Limp Home Mode" (allows 1500 RPM max.), the most voltage sensitive of the dash instruments, the engine temperature instrument, spikes high, oil pressure instrument "flails" on idle RPM. Further down in voltage, at 9 Vdc decreasing, the ECM for the transmission starts misbehaving.
At any rate, (a real) low battery voltage will give strange behavior in exactly the parameters that you have mentioned. And, a low dash voltage, downstream of the "ignition on" relay contacts, will give these symptoms. Sudden onset of unreasonable temperature swings (and rapid temperature fluctuations high) provides the red flag regarding dash low voltage problems on the mechanical 8.3 Cummins.
In a jam, if the "limp home" condition persists and you end up beside the road and you are unable to clear the condition, I have been able to temporarily improve it by cycling the Boost Switch rapidly several times, or, if you can shut the engine down, rapidly cycle the ignition off and on several times. Of course that's only temporary and the next downshift of the transmission on a 2% uphill grade, while under cruise control, may provide just enough jarring of the ignition relay contacts, or change in electrical demands on the engine start batteries, to shift voltages down enough to provide onset of the condition again. BTDT
HTH
Neal
I agree with those who believe it's an electrical problem, and I think you've received excellent information so far.
I also agree with the suggestion to keep spare fuel filters and to know how to change them. It's also a good idea to use an algaecide. The one I use is Biobor Jf Fuel Additives - Products (http://www.biobor.com/products/biobor-jf-fuel-additives/) and I highly recommend it. It's available from West Marine, Amazon and other places.
I would change the ignition solenoid.
Not expensive and even if that's not the problem the one on there may be original and a problem in the future.
Keep the one you take off. If that change doesn't fix it you have a spare for an emergency.
Tim,when you get time finish filling out your signature and put your coach in so we remember what you have.Also,check your
return throttle springs they are located where the cruise control wire is on curb side of engine,should have 2.
I knew there was a reason for getting a Foretravel: a very knowledgeable and kind group of supporters. Thanks so much for your replies. I tightened all 100+ terminal nuts in the front electrical panel. One of the power terminals that supplies a buss bar was quite loose, and required about three turns of the socket wrench. I am lead avionics engineer / technicial for our local EAA chapter, EAA 1250, so I am familiar with busses and power distribution. The distribution panel looks very well-designed and clean, for a 1997.
You have given me some peace of mind on this 2700 mile journey home. Only 6 hours of driving to go. Your help will make those miles more enjoyable knowing that your thoughs and ideas are with me.
Fuel filters that are plugged shouldn't be able to restart the engine. I go with electrical. If you loose power to the fuel solenoid the engine stops even momentarily. Having a loose terminal may have been the problem. I find a lot of times it is something simple.
Good luck
No engine shut downs yesterday. The Water Temp (Coolant) gauge pegged intermittently high off scale after slowing to a crawl in traffic. I believe this is a separate problem than the engine shutdown or power to the instrument panel because all of the other instruments were performing normally.
I will definitely replace the fuel shut off solenoid, fuel pump and trace down a potential chaffed wire for the coolant temperature sender when I get home.
Tim,
When you get a chance, put your coach information in your signature. That way, when you have a question, we will be able to better assist you with correct answers for your coach.
Tim,
Please add your coach model, year, size etc. to your signature in your profile in ForeForums
Thanks!!
What I learned, as well, is to put the build # on your sig, that's helped a lot of members who's coaches are close. ^.^d
Updated signature. Made it home with only one 5 second engine shutdown. It occurred when I was manipulating the cruise control. At 45MPH, the cruise control would not enter into "Resume" mode, nor did the gas pedal work for about five seconds. After I shut off the cruise control, the gas pedal became active. Does anyone know if the throttle has a cable to the gas pedal or if it is a fly-by-wire electronic system?
Both, potentiameter in treadle produces signal that goes to King box. Controls spool that winds cable to throttle. Should be a guide in owners manual. If you don't have it let me know and I will get it scanned. Excellent trouble shooting materials on company site. Also Beamalarm is good for diagnosis and work around.
Tim,
The 5 digit number 1xxxx is the Motorcade Club (travel club) number that belonged to a previous owner of the coach. That number stays with the person.
The build number of the coach is a 4 digit number and is in your 4 model number, which starts F99 for a 1999 coach. It's on the plate on the wall near the driver's knee. The build number for a '99 should start with a 5. Here's how to read it Build Number (http://www.foreforums.com/index.php?topic=11878.msg60685#msg60685)
Does the engine shut off, or does it lose power? And then, after pushing the brake pedal for a split second (to turn brake lights on) and then push the throttle down again, does the engine regain power?
This is a symptom I run into. I called king about it, and bascially I think the stepper motor is "slipping" for lack of better term. Long stretches of cruise control and the actuator slips and when commanded to go to 100%, it only goes to say, 60% or lower. The transmission may kick-down a gear, but the motor won't make the power.
I reset the actuator by pushing the brake pedal and then I get full power back. It's annoying when climbing a hill. King can fix it by sending the actuator box off to them....I just haven't got around to it.
On level ground it really isn't a problem.
I'd say your gauge problem is separate issue.
The engine looses power in that the cruise control and accelerator pedal are dead. I Believe you are right and that the cruise control disengages but does not hand control back over to the footpedal. When the cruise control is disengaged then the gas pedal becomes responsive again. Since the cruise control works 99.9% of the time. I probably will not take any action at this time.
Tim,
When this happens again, you can rule in/out the IGNITION SOLENOID: The dash HVAC fan and anything else that only works with the ignition solenoid working will stop working if this is your failure point. This includes the Allison shift pad illumination.
Sounds like the same problem as me. When the coach is parked, send the box off to get rebuilt at king.
What appears to be happening is that after long durations of cruise, the actuator will not open the mechanical throttle lever on the engine. Thus, it is not an engine problem.
If you send it to them, great folks to talk with by the way, ask for a bench test before the rebuild. I think it is $75. Rebuild about $450 or so. Even if you decide to rebuild as a preventive measure you may actually know root cause. Nothing more frustrating for me so far with my coach than not doing proper root cause analysis before making a repair.
I had the same problem with our U270, we had it repaired twice, after the second time I installed an air throttle, now the cruise control is just that a cruise control, if the control fails I still have a throttle, in 2014 the cruise failed on a 9000 mile trip, after many hours of testing it was the Smart Wheel control that failed, but I still had a throttle .
Side note, you should test the brake light switches, you could have one sticking.