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bounder39zman's avatar
bounder39zman
Explorer II
Aug 09, 2014

Dead Cummins ISB/275

Looking for some help with Cummins ISB/275hp in DP motor home.
Started normally, backed it out of garage, went to close garage door and engine stopped, just like key switched off. Will nor re-start. Cranks at normal speed, but not seeing any sign of smoke out of tailpipe. Changed fuel filter, checked electric lift (supply) pump, it is running and have fuel delivery when cranking. Any ideas? Also, anyone know how to release spring (parking) brake, as I have no air pressure due to no engine running..so I can pull vehicle back into shop?
RV is on a Freightliner chassis, with an electric throttle mechanism. Any suggestions would be appreciated...I can swap for Generator info, as I work on Onan/Kohler/Generac, etc at my work
Class A
  • hershey's avatar
    hershey
    Explorer
    Aug 11, 2014
    You said you replaced the fuel filter...was that before you started it? If so, I'm betting you didn;t prime the system well enough before starting. If so, bleed the injectors.
  • teddychamp's avatar
    teddychamp
    Explorer
    Aug 10, 2014
    Do you have any Warning lights on Dashboard ? I had the same problem not to long ago and it turned out I had 3 wires shortened out to fuel pumps. Had also 2 blown fuses in the battery compartment. Dashboard showed "Check Engine" only.
  • dakdave's avatar
    dakdave
    Explorer
    Aug 09, 2014
    mine has a tire like stem on air gryer you can use to fill air tanks
    dave
  • bounder39zman's avatar
    bounder39zman
    Explorer II
    Aug 09, 2014
    thanks for quick replies. I checked fuel delivery at low pressure (12V)electric supply pump. I have not cracked injector line to check fuel delivery from Injection pump. Air filter is disposable type, restriction indicator not pegged, but removed filter and tried just in case. no better. I have air chuck installed at front(for air horns, tire inflation, etc). but has a check valve somewhere in line, will not let air from shop compressor get to brake air tanks
  • John_Wayne's avatar
    John_Wayne
    Explorer II
    Aug 09, 2014
    Do you have a chuck on the air manifold to inflate your tires from your air tank? If you do, do you have an air compressor? if so back feed the air into the air manifold to your air tanks to get the MH back into the garage.
  • SeaDog_BRR's avatar
    SeaDog_BRR
    Explorer
    Aug 09, 2014
    You say you have fuel delivery when cranking are you testing the high pressure side of the engine driven fuel pump?
    1. Check that there is nothing obstructing the air intake
    2. check that the high pressure side of the fuel pump is truly putting out fuel
    3. bleed fuel system to remove any air and ensure the injectors are getting fuel

    when turning over with fuel and air it should start

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