ISM eating injectors

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by BoxCarKidd, Jun 8, 2021.

  1. BoxCarKidd

    BoxCarKidd Road Train Member

    4,167
    5,981
    Aug 26, 2014
    0
    Replaced four during inframe, the other two were only about a year old.
    Two days later it had two dead cylinders. Swapped those injectors with two others. Misfire went with the injectors. Replaced them and it ran smooth. That was 2 of the 4 new remans.
    Four months later it dropped two cylinders. Replaced those injectors and it ran smooth. One was of the new group and one of the older ones. It had a top end knock that would stop when #6 was cut out. It ran OK and injectors were out of stock. We were in a bind so put it on the road ( local ). Three days later it is a five cylinder but injectors are in. We will replace it tomorrow.
    This is in an 08 IHC 76 or 7700. Injectors look the same as N14 Celect.
    Anyone ever ran into something like this? Suggestions what to check and possible cause will be appreciated.
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. truckerbangin

    truckerbangin Light Load Member

    255
    43
    Jan 22, 2013
    0
    I’m having the same exact problem with 2004 international 8600 with Cummins ism in it. I replaced 3 six pack of injectors and after a week or two of running fine, truck will start to miss again. I’ve been chasing this problem for two years now.
     
    BoxCarKidd Thanks this.
  4. Inderjit

    Inderjit Medium Load Member

    609
    601
    Sep 17, 2017
    0
    When the N14 first came out it had quite a few injector problems that meant
    replacing injectors under warranty. There was a high incidence of the new injectors
    failing after a short period of time. We blamed the failures on Cummin's poor
    Recon parts quality. The ISM uses the same series of injector as the N14.

    On the next Cummins training course I went on they taught us that the failures were
    a result of fine metal particles that came from the valve and injector springs wearing
    against the head and valve spring caps and injectors. These particle mostly wash
    down into the oil pan and end up in the oil filter but some particles go down the
    injector bore in the head and sit on top of the top O-ring on the injector. When the
    injector is removed the particles go down the injector bore and can end up in the fuel
    passage causing injectors to fail.

    We were told to clean the oil from the area around the injector before removing
    it so it would not run down the injector bore and to clean the injector bore with a
    lint free rag immediately after removing the injector.
    After following their procedure the failure rate went down considerably.

    Cleanliness is very important when working on a fuel system. It only takes one speck
    of dirt to make an injector fail. A mechanic wearing dirty coveralls or handling rebuilt
    injectors with dirty hands is a problem.

    Its also possible that the accessory drive is out of time, as in not installed properly
    and you are setting the injectors in the wrong spot.
     
    Last edited: Jun 9, 2021
    spsauerland and BoxCarKidd Thank this.
  5. spsauerland

    spsauerland Road Train Member

    4,296
    10,876
    May 31, 2010
    West Harrison, In
    0
    Have a 08 KW that is same way, replaced first one with less than 50,000 miles on it. It has 750,000 on it now, I have replaced everyone at least once, some more. Always seems to have a long crank time, even brand new. Always used fleetguard FS1000 on it. I always thought Cummins lacked on good fuel filtration on the Celect platform.
     
    BoxCarKidd Thanks this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.