Code on Fuel-Injected Engines (EFI Kohler on Exmark Lazer)

Discussion in 'Mechanic and Repair' started by Cboy7, Sep 29, 2009.

  1. Cboy7

    Cboy7 LawnSite Senior Member
    from Fl
    Messages: 386

    My EFI kohler has been to the shop many times , and they cant find the problem.

    When it gets hot.. after 3-4 hrs of use, it will gasp and snap and sputter like its runnig out of gas, or like its timing is off.

    I can bleed the fuel line , and it helps a bit.(always seems to have air in line when hot.

    I can park it under a tree to cool it off , but it sounds horribly unprofessional , and I am wondering if any other EFI owners have had a problem.

    The blinking red light code gives this... 3 blinks pause, 4 blinks , in this order

    i need a new cpu module?
  2. Oldtimer

    Oldtimer LawnSite Bronze Member
    Messages: 1,459

    Has the dealer used a computer to diagnose the problem?

    How old is the unit?

  3. Cboy7

    Cboy7 LawnSite Senior Member
    from Fl
    Messages: 386

    yea, but the codes throw him off.

    its about 4yrs old

    JABBERS LawnSite Senior Member
    from Ohio
    Messages: 459

    I have had a problem with mine for about 4 years come and go no rhyme or reason. I believe a code 34 is the oxygen sensor. I have replaced several things, oil sending unit twice oxygen sensor twice, fuel pump, rocker arm came off, and replaced the lifters and its finally fixed.
  5. Cboy7

    Cboy7 LawnSite Senior Member
    from Fl
    Messages: 386

    would a bad fuel pump make sense only when hot??
    I have been thinking of replacing that , since it does grunt and groan , and sometimes seems to have air in it , and not pushing gas.
  6. Cboy7

    Cboy7 LawnSite Senior Member
    from Fl
    Messages: 386

    "oil sending Unit" ... is that something easy to replace??? I have felt for some time , like it must be a cooling issue, with not sending enough oil through the machine...

    any one know??
  7. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Messages: 1,791

    I may be way off on this, and I'll explain. Back in the day I had a 64 Pontiac GP with the big 455 engine. It would run great in the winter, but come the summer, you could not take it for long drives. Problem was the the fuel line ran near the headers, causing vapor lock, fuel bubbling in the fuel line. At the time, I wasn't going to put the time or effort in to rerouting the fuel line, the beast was a beater :laugh: Now my cheap fix at the time was to wrap the fuel line ( it was metal ) in aluminum foil, like a heat shield.

    My suggestion would be that the next time this happens, trace the fuel line back and see if there is any place where it is really hot. If you find a hot spot, either move the fuel line or make up a heat shield and see if this works

    Just a thought.. Good Luck :drinkup:
    ericg likes this.
  8. Cboy7

    Cboy7 LawnSite Senior Member
    from Fl
    Messages: 386

    Thanks, I do appreciate it.

    I dont think there is uch to be able to change since some of the gas lines run through metal tubing tight close to the carb intakes.
    It didnt use to do it.
    another theory was the ethanol in the gas.

    i looked up the code 31 and 34 are both from running lean , which could be vapor lock , but it alos mentioned the fuel pump , fuel condensor and oxygen sensor.

    I may just order those all and install it myself.

    i wish they could give me real gas again without the ethonal ... messing up my small equipment too.
    i use sentry plus gas additive for that , helps some.
  9. ricky86

    ricky86 LawnSite Silver Member
    Messages: 2,135

    If it's running that lean, you better fix it quick.Both the codes are related to the o2 sensor. That doesn't mean it's bad. Could have lost ground, exhaust leak or bad connection or sensor. Check the fuel pressure first at the fuel rail. You need 40psi. How old is the high pressure filter? Code 34 could be a bunch of things. Check the simple first. You didn't add an other fuel filter into the system?
  10. Cboy7

    Cboy7 LawnSite Senior Member
    from Fl
    Messages: 386

    No I havnt added a filter.

    I bought it used about 2000 hours ago , and filter hasnt been changed. But i dont think that would make it skip and pop when hot only. needs to be changed anyway I guess.

    How do I check the fuel pressure?? i need a special guage? any ideas where to order one?


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