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  1. #1
    Riko's Avatar
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    Cold engine shaking

    Ok guys here is my problem..when i start the ski with cold engine it starts to wobble/shake and it sounds like crap...also rmp varies from 1650-1900.When it warms up it runs fine for the rest of the day.So please i need your help on this one!

    Things i ve done until now:

    new oil
    new spark plugs
    charged battery
    fresh fuel 100 oct
    swapped injectors
    swapped coils
    cleaned TB/TB hose/idle valve (with battery off)
    cleaned intake manifold
    cleaned MAP sensor
    compression test showed 1)125 2)127 3)140
    changed fuel pump last season


    From my exprerience it seems like a fuel/spark problem...but i am out of ideas... :/


  2. #2
    Sanfish's Avatar
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    Maybe it could be built up condensation (water) that eventually gets blown through motor.

    To test, next time you start a cold motor, remove the large air hose at the throttle body. While seat off, start ski in water and ride while looking at hose outlet. Some condensation is expected but shouldn't be that much (hard to explain in words) and quickly stop.

    Only other thing I have is drain 100% gas and put fresh gas. If you have some water in tank, it will settle on bottom and on first start up, since its not mixed from riding it could be picking up water.\

    Does it have same symptom if you let ski sit for 15 minutes or must it be completely cold?

  3. #3
    Riko's Avatar
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    It happens every time the engine is completely cold..for example if i ride and then let it in the water for 2-3 hours and start it again it will be fine .I drained the fuel tank completely and then i added new fuel..nothing changed! :/

  4. #4
    GasResearch-VT.SE's Avatar
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    Could be a bad sensor somewhere, maybe try logging the sensors on cold start with BUDS or vtech logger.

  5. #5
    Riko's Avatar
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    Quote Originally Posted by GasResearch-VT.SE View Post
    Could be a bad sensor somewhere, maybe try logging the sensors on cold start with BUDS or vtech logger.
    Is that possible?I mean a sensor reading wrong only when ski is on "cold start mode" ? I will give it a try!

  6. #6
    Kosh's Avatar
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    How long does it wobble and shake for before settling down?
    have you checked fuel pressure?

  7. #7
    GasResearch-VT.SE's Avatar
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    yes.... or your fueling is up the poo

  8. #8
    Riko's Avatar
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    Kosh it wobbles for about 1-2 minutes as much as cold start takes...when rpms drop to normal operation everything works wonderful! No i didn't check fuel pressure yet...i have an aeromotive regulator on the way and waiting to receive it so i can install it...If my fuel pump or fuel regulator crapped out wouldn't this effect the engine even after cold start?

    Gas by fueling you mean gasoline?pump?FR? or all together ?

    Thanks!

  9. #9
    GasResearch-VT.SE's Avatar
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    I mean if you running 10:1 cold start afr then it makes sense. Or too lean

  10. #10
    Riko's Avatar
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    I don't have a tap for sensor in my exhaust yet so i can check my afr..but i have an idea.What if i install just for 2-3 minutes smaller injectors(38 for example so i can be leaner) or bigger than 42s (so i am richer) to see if any of that will affect how engine is working?
    Do you think it will work?

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