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Engine dies when working hydraulics

Discussion in 'Excavators' started by ktm250rider, Sep 11, 2010.

  1. ktm250rider

    ktm250rider Well-Known Member

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    Location:
    canterbury nh
    Well, I replaced all my filters (air, fuel oil) and I seem to still have the same problem on my 96 Hyundai 130 LC-3. After working the machine for 3-4 hours, the engine rpms start to drop when putting a load on the hydraulics. It would start to drop by 2-300 then 4-500 rpm. It seems to run fine when cold. I noticed it start happening again today while digging in a pile of dirt. I released the controls thinking the rpms would come back up but the engine died. Took a lot of cranking to start back up (i didnt want to leave the boom in the air).
    Ive read the "hitachi 120 problem" post and Im thinking this may still be a fuel issue. At least I hope its a fuel problem and not a lack of compression or engine related issue.
     
  2. swampdog

    swampdog Senior Member

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    Does the machine have a small screen somewhere in the fuel line? A lot of excavators have a screen hidden at a Banjo bolt fitting near the fuel pump. If you have that, cleaning it might be an easy fix.
     
  3. ktm250rider

    ktm250rider Well-Known Member

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    dumb question, where is the fuel pump? Near the tank or on the engine?
    It wont even start now, just turns over and over.
     
  4. YELLOMTLMILITIA

    YELLOMTLMILITIA Well-Known Member

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    injection pump is on the engine
     
  5. powerjoke

    powerjoke Senior Member

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    possible collapsed or plugged fuel line, try taking it off the injector pump and fallow it clear to the tank. and make sure you have fuel flowing out the end of the line, if not check for a restriction....

    you have changed the fuel filter?

    Pj
     
  6. swampdog

    swampdog Senior Member

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    That little brass filter usually is between the fuel filter and the injection pump. Have a look before the injection pump for a banjo type fitting and see if a screen is hiding in there.
     
  7. loggah

    loggah Well-Known Member

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    New Hampshire
    I had a john deere 653 fellerbuncher that acted the same way, worn out injection pump. when its cold the tollerances were close enough so it ran, as the engine and pump warmed up it would run slower and slower, and if you shut it off hot it wouldn't start again. You let the engine and pump cool off and it would start and run again,finally just wouldn't run at all. I put a new injection pump on it and no problems after that. The john deere had a rotary fuel injection pump on it,not sure on the hyundai. Don
     
  8. eianewb

    eianewb Well-Known Member

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    eastern iowa
    ktm250rider, when you find the problem, please let us know what it was. i have a similar issue with my kobelco sk130. i have dinked with it for a couple weeks, found nothing wrong, and it finally started running fine again, every once in a while it will act up again, but it seems to go away. i am just lucky i don't HAVE to use it all day every day, as i am just a farmer.

    good luck.
     
  9. watglen

    watglen Senior Member

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    Occupation:
    Farmer, drainage and excavating contractor, Farm d
    Location:
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    My combine started that just yesterday, would die under load, but idle fine, run fine lightly loaded. Sometimes it would miss, and and run rough. Quickly diagnosed it to be a faulty lift pump. The dead giveaway was when you turn the key on you could always hear the lift pump running, then yesterday you couldn't.

    Problem solved.
     
  10. ktm250rider

    ktm250rider Well-Known Member

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    Location:
    canterbury nh
    Im thinking mine is definatly fuel related. Had a friend come over yesterday and we bleed it by loosening the injectors rather than the bleed screws. Fired right up and ran fine. I was planning on removing the filters and reseating them to watch for any leaks. Apparently last night we never tightened the last injector so now Ive got an engine covered in diesel. Fat chance Ill find the leak now.
     
  11. sultan

    sultan Senior Member

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    Location:
    Ontario, Canada
    Usually tiny fuel leaks by themselves don't cause such problems. What it sounds like to me is a blocked small filter screen upstream of the pump. It's not the main fuel filters, or at least I very much doubt that it's them.

    A couple years back, I had a tractor that would run for a few hours and then die out on me. It seemed to lose it's prime while running, and stall without producing too much smoke. I bled the fuel system and it would run another few hours and then die again. Eventually I called my mechanic to look at it, and he discovered that the tiny filter at the outlet of the fuel tank was clogged, and that was creating a vacuum in the fuel lines (because the injector pump kept on sucking). Eventually the vacuum built up to the point that some air got sucked into the fuel lines somewhere and that would stop the engine. Replaced that tiny filter, and not a problem for 2 years now. So I think its some tiny screen upstream of the fuel pump that is your issue.
     
  12. dannymcivor

    dannymcivor New Member

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    We had a similar problem with a JCB JS130 and found out it was not a fuel injection problem but a problem with the hydraulic pump but we still havent got to the bottom of it. Apparently when the pump is working at full pressure for long periods of time it will kill the engine. I would be interested to find out how you get on with your machine.
     
  13. ktm250rider

    ktm250rider Well-Known Member

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    So far, all is going good. Tightened that injector nut and havent had a problem. Now if I could just do something about loosing bucket teeth all the time. Good thing I got extras.
     
  14. tonyirish79

    tonyirish79 Member

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    removed post
     
    Last edited: Oct 1, 2010
  15. Tinkerer

    Tinkerer Senior Member

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    Post not relevant to topic
     
    Last edited: Oct 2, 2010
  16. jcbmanuk

    jcbmanuk Member

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    uk
    is it rubber lines to the pump? have seen these collapse internally!

    good luck
     
  17. ianoz

    ianoz Senior Member

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    Location:
    australia
    You may find the tooth adapters are worn,and the tooth moves on the adapter untill the retainer rubber fails and the pin breaks or falls out .. If the tooth is loose on the adapter ,its time to replace them .Ian .
     
  18. tugarul3z

    tugarul3z New Member

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    portugal
    Did you checkout the turbocharger?Happens to me on a hitachi zx670...the turbo was broken....
     
  19. Iron@Dirt

    Iron@Dirt Senior Member

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    south lou.
    Have seen piston pumps on tractors act up and get well over 4000 psi, but dont know if it would kill your engine. With temp gun you might pin point hottest spot, pump, gear drive etc.