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Executive45's avatar
Executive45
Explorer III
Apr 14, 2019

UPDATE: Hard starting Cummins ISM

Good Morning everyone! Cummins ISM. 95,000 miles. Just had it serviced, replaced water separator, filters etc. including Allison transmission service. Generally used Speedco for service but tried out a new facility in Arizona. My engine has always started within 3-5 seconds, I'll call it a short crank. After service it will still start but it now takes a long crank. That's the best way I can describe it. I'm not used to cranking an engine for an extended period of time. What could be the cause? It appears they used the correct water separator when it was changed Racor RK12963. Any insight will be appreciated....Dennis
Class A
  • wildmanbaker's avatar
    wildmanbaker
    Explorer
    Apr 14, 2019
    Contact the shop and voice you concerns after the service. There may be a small leak allowing air into the fuel line.
  • grldst's avatar
    grldst
    Explorer
    Apr 14, 2019
    Are you using the water separator with the clear bowl on the bottom? Some installers get confused as to proper installation of seals on these.
  • JaxDad's avatar
    JaxDad
    Explorer III
    Apr 14, 2019
    Typically a longer crank to start after a service would indicate you still have some air in the system. Unusual on a newer diesel, but not unheard of.

    How far / long have you driven it since the service was done?
  • ppine's avatar
    ppine
    Explorer II
    Apr 14, 2019
    Try some additive for diesel to make sure you have gotten all the water out of the system. Many will add some cetane which makes for easier starting. They help take out some varnish in your engine.

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