can't get past 2600 rpms

Discussion in 'Gas Engines' started by molokai bro, Mar 21, 2006.

  1. molokai bro
    Joined: Mar 2006
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    molokai bro New Member

    2001 shamrock 420 hrs 5.7 pleasurecraft. Checked compress,spark ,dist and changed ecu at manufact suggestion after test indicated all electronic systems ok. Where do i go from here?
     
  2. Jango
    Joined: Aug 2005
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    Jango Senior Enthusiast

    Sounds like all there's left to check is Fuel - Fuel Injection, perhaps Fuel pressure?
     
  3. molokai bro
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    molokai bro New Member

    Max 2600 rpms

    Thanks but presure is almost 15 lbs at the injecter rail. Computer tells us motor using 1gal at 1000, 7gal /hr at 2000, and 15 gal /hr at 2600 rpms plowing trying to get up on plane. Normal to burn 10- 12 gal/hr cruising. I'm stimied so is pleasure craft and mechanic. Any other ideas would be appreciated, Mahalo , Molokai Bro
     
  4. longliner45
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    longliner45 Senior Member

    dose the engine miss or cut out at higher rpms? sure you have checked your air intakesand cleaned rakoars and or filters for fuel problems,,,,,,,,water,if that dont help I would go back to manufactureand put it on the computer could be a chip or sensor problem
     
  5. molokai bro
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    molokai bro New Member

    longline45

    Runs without any miss or any indication until it hits 2600 rpm and then it fells like a governor kicks in . put throtel all the way down and no change.Have changed filters both air and fuel. didn't check injectors as computer indicated it was going thru a lot of fuel? What are rakors? Appreciate any other help,
     
  6. longliner45
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    longliner45 Senior Member

    raykors ..spelling ? are fuel filters that catch water in diesle engines, ,,sorry for not being to much help.
     
  7. longliner45
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    longliner45 Senior Member

    dont know if you have em but vacuum lines could be collapsing under strain at higher rpms?
     
  8. RHough
    Joined: Nov 2005
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    RHough Retro Dude

    Did it ever get up on plane and run over 2600?

    What has changed since then?

    Did it slowly get worse or just stop running over 2600 all of a sudden?
     
  9. Ari
    Joined: Jan 2006
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    Ari Patience s/o Genius

    Your exhaust system checked ?Do this engine have RPM kill switch ?set properly?
     
  10. molokai bro
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    molokai bro New Member

    Molokai Bro

    Aloha and a big mahala to all how helped. The boat had sat during the heat for 5 months. Water must have gotten past the 2 fuel filters and corrodided the injectors. so bad that first rail injejtors when disconnected individual didn't change idel at all. corrision even under o ring on alum rail. openings on 2 almost closed at opening don't see how it even ran not alone how it ran smooth.Mechanic said that's the last thing they would check. Verifing injector elecricaly then visually a lot quicker and less expensive than changing the ecm as reccommended by Pleasure Craft and the Marine service center. Hope this might help someone else
     
  11. bilgeboy
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    bilgeboy Senior Member

    Glad you found it, sounds very fixable.

    I just wanted to add to Longliner's thoughts. He was suggesting you check the Racor's, and if you don't have them, I think you want to install them.

    They are water separators with a filter. Dahl is another popular brand, but nowhere near Racor. They'll save you this aggravation in the future.

    Good Luck

    Mike
     
  12. longliner45
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    longliner45 Senior Member

    thanks for keeping us up on it, I was curious,thanks
     

  13. gonzo
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    gonzo Senior Member

    Pressure should be around 39 pounds at the rail
     
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