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Topic: 1999 U270 8.3 CAPs Starts but won't stay running (Read 2073 times) previous topic - next topic

1999 U270 8.3 CAPs Starts but won't stay running

Hello everyone,
I just inherited my Grandfathers 1999 U270 and I am trying to get it back on the road after sitting for 7 years. I have been searching forums for the last couple of weeks trying to find answers and I'm about to give up. The coach will crank and sometimes stay running for 3-4 seconds then it shuts down. The start batteries are brand new along with 1 house battery. I went thru the fuel system, replacing fuel filters and a manual primer. While I had the fuel system open, I hooked a Jabsco pump up to the main fuel line and pumped about 30 gallons of fuel thru a Dhal fuel filter/water separator, to check the main tank for algae, water or debris, it was all clear. I also verified no air leaks and plenty of fuel flow thru the system. I have bled the fuel system up to the injectors and it still won't stay running. The Cummins CAPS fuel injection does not have a fuel shut off valve so I'm out of ideas. All other fluids have been serviced/topped up and any ideas or suggestions are welcome.   

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #1 –
Have you looked to see if there are any codes on the ECU?
Could be shutting down due to engine protection condition like low coolant, no oil pressure, or something else.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #2 –
I have not been able to read the ECU. I have one of my kids looking up a reader now.

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #3 –
I had problems starting my 1999 u270 after changing fuel lines won't stay running so I remove one of fuel cap and put air in to tank with a rag to cover up the hole it ran and keep run forcing the fuel to the engine after I found a kink in the line try putting air in tank don't go over bored with the air pressure
Rick & Hilda looking forward to full- timing one day for now couple of months at a time
1999 U270 3602
Built number  5530.  Feb 1999            Motorcade  number 18438
8.3 Cummins Allison six speed with brake  retarder
Purchased Nov 28 2019

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #4 –
Quote from: Jim K –
The Cummins CAPS fuel injection does not have a fuel shut off valve...
Jim,

It sounds like you have a good understanding of the fuel system on the Cummins 8.3 and have covered most of the usual suspects.

You said your engine does not have a "fuel shut off valve"...  Does it have have a fuel shutoff solenoid?  If it is getting intermittent power, it might open (ignition ON) to allow the engine to start, then if it loses power might close and shut the engine off.  See the thread below for more info:

Fuel shutoff 1996 c 8.3

If the fuel shutoff solenoid is not your problem, then you may be having trouble with the CAPS fuel injection pump.  Some of our members have had CAPS problems.  I will link some threads below pertaining to CAPS.  See if they are of any help.

Cummins ISC CAPS intermittent stop engine light (long!)

OEM Fuel Cooler Replacement

Stop engine flicker
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #5 –
There is a thread on irv2 in the Monaco section where a guy has been having  a hard time getting his coach back running  while he is in Denver or close to it. Thread is very long, but lots of good information. When I get to a computer I will post the link
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #6 –
Dead on road. - Page 29 - iRV2 Forums

Here is the link
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #7 –
Check the coolant level. If it's below the sensor, the engine won't start. This happened to a surviving spouse as she could not pull it out of it's garage plus it was too close to the back wall to add coolant. A member went to assist her.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #8 –
Jim,

If the engine is actually running for 2 to 3 seconds at times this could be either sensor is failing or you have an electric plug that has a wire that is loosing contact from vibration.  There should be a flag down in the engine ECM if you have something like the oil pressure sensor failing (that is one that will shut the engine down)

Mike. 
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #9 –
Fuel, air, and the commands from ECM to run.  Sounds like you have updated the fuel system-good.  Have you checked the air intake system completely?  I remember one forum member found a nest way up in the system past the filter. Without clean air it won't stay running.  If air system is clean then I would think it is electronic ( ECM), wiring bad, or part of the CAPS pump itself gone bad.  Do verify that fuel is being pumped if possible and maybe put a fuel pressure gauge in the line- some on the forum have done this. 

Best of luck getting her running................... ^.^d
Ted & Karen
2001 U270 36' - sold after 12 years full timing

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #10 –
OK, code reader has been ordered and is on the way. After reading the 30 page post (thanks for the link Turbojack ) I am confident I will get it running, but, I'm also a lot less confident that I can actually afford RVing. Y'all have an expensive hobby. I really hope it's not the CAPS.   

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #11 –
Quote from: Jim K –
OK, code reader has been ordered and is on the way. After reading the 30 page post (thanks for the link Turbojack ) I am confident I will get it running, but, I'm also a lot less confident that I can actually afford RVing. Y'all have an expensive hobby. I really hope it's not the CAPS.

The code reader is a great idea.  If the code reader does not lead you to success, do not be afraid to spend an hours labor with a mobile hd truck mechanic.  You might check with your local Napa or HD Truck auto parts store for a referral.
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #12 –
Jim- let's hope it is not the CAPS, however I found from experience that there are 2 ways to deal with the CAPS.  When I was having trouble with mine, I went to Cummins Coachcare in Arizona, just outside of Phoenix.  They had treated others on the forum well and knew what they were doing so since I was out west I managed to limp in.  It turns out the CAPS pump system has 3 separate parts- mine was the accumulator.  They replaced it ( took most of a day) and it was maybe 1/3 of the cost of replacing the whole CAPS pump.  Again, they had good techs who knew what they were doing and how to do it.  Still not cheap but that new system is still running well in the coach with her new owner.  I did post on the forum about it if you want to search for it- about 4 years ago I think.
Wow- it has been almost a year since we sold our coach/home for 12 years and 110,000 miles full timing. 

Best of luck getting your coach running-it is worth it.                  ^.^d
Ted & Karen
2001 U270 36' - sold after 12 years full timing

Re: 1999 U270 8.3 CAPs Starts but won't stay running

Reply #13 –
Short update. No joy on the code reader. The reader appears to work, it hooks up and reads, it's just not showing that there are any active (or historical) fault codes. After the New Year I will be calling a local mobile mechanic that I was referred to by a friend. From here on out parts are expensive and I want to be right. My brain is stuck on the fact that the coach ran fine when I parked it, although realistically it has been 7 years and things that are meant for the road don't like to sit and I understand that. On a positive note, the generator is running strong, the A/C's work great, the fridge works fine and most of the lights work.