ML270 Cdi slow starting.

Discussion in 'Engine' started by BIGjoe, Nov 28, 2008.

  1. BIGjoe

    BIGjoe Active Member

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    For several weeks I've been aware of the car taking slightly longer than normal to fire up from cold. Well this morning it was not having it, after several attemps it refused to fire at all. A quick look at the exhaust and no vapour, so lack of fuel hence no ignition. A burst of easy start got it to fire and away she went. The tank was nearly empty, so I'm thinking fuel pump/lift pump not pressurising the injection system, is this giong to be expensive :(.
     
  2. panason1c

    panason1c Hardcore MB Enthusiast

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    More likely to be one or more injectors faulty.
     
  3. Dieselman

    Dieselman Banned

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  4. OP
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    BIGjoe

    BIGjoe Active Member

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    Thanks DM, thats what I'm thinking it may be, when the tank is full, it starts instantly, but below half full starting takes longer as all the fuel in the system has run back into the tank drawing in air as it goes.
     
  5. OP
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    BIGjoe

    BIGjoe Active Member

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    Had an investigation today, can't see a lot wrong, but going to try replacing the pipe between the filter and pump. Whilst the plastic top was off, was amazed to see a mass of black gunk around an injector, one of the infamous copper seal failures no doubt :crazy: , and another job to boot.
    I've heard horror stories about getting the injectors out, is it best engine cold or hot, and any other tips.
    TIA.
     
  6. OP
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    BIGjoe

    BIGjoe Active Member

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    Right, finally got round to having a play:eek: under the bonnet. No 3 injector has a serious flow of fuel through the return port, so is goosed and no doubt the cause of the starting problem, and every other injector is leaking combustion past the seal in different velocities, except No3 of course:rolleyes:.
    Looks like I know what I'm going to be doing over christmas:confused:.
    Any tips for removing gunked up injectors, is it easier when the engine is hot?, and is it worth using a liquid gasket with the new sealing washer. I've used blue goo on other machinery in the past with succes:cool:
     
  7. OP
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    BIGjoe

    BIGjoe Active Member

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    Ok, job sorted. after a good long run, the carbon was nice a soft , so it came away in great big lumps. The injectors came out without to much of a struggle, found the best way was to loosen the retaining bolt first, and with electric plug and fuel pipe still connected, start engine which dislodged the injector, then remove bolt/electrics/ fuel pipe, and then slowly twist back and too with mole grips until injector could be pulled clear. A thorough clean and a good blast of compressed air, then replaced injectors with new washers/liquid gasket and bolts, with a new injector for no3 cylinder (£143, Merc Warrington).
    Result:now runs as sweet as a nut, with instant starting (-5' here yesterday morning:D)
     
    Last edited: Dec 28, 2008
  8. jaymanek

    jaymanek Authorised Forum Sponsor Authorised Forum Sponsor

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    You are lucky they came out so easy... they are not always so... we have invested in a Klann removal kit as normally they are stuck solid..
     
  9. OP
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    BIGjoe

    BIGjoe Active Member

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    Wasn't I :D, after reading so many horror stories about the blessed things refusing to leave their nests I was dreading the job :crazy:
     
  10. proser

    proser Hardcore MB Enthusiast

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    I found Mr Muscle oven cleaner was very good at cleaning everything up and dissolving the carbon build up.:)
     

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