May have a problem

Discussion in 'eXmark' started by Keith, May 8, 2003.

  1. Keith

    Keith LawnSite Gold Member
    Posts: 3,977

    Yesterday while using my EPS Lazer, I made a turn and as I pushed both levers forward, the mower stumbled and felt like it lost some power. I played around with it in that lawn some more and it felt like it was struggling as you pushed the levers all the way forward. The engine seemed to be bogging down and then trying to catch up. I had also noticed it was having a little trouble discharging grass in some spots. On top of that, when throttling up with no load, you could see some black smoke, like it was running really fat. Never had I noticed that either. I pulled it up on the trailer and hopped off and ran it up to full throttle, no load, and you could see just a whisp of black smoke exiting the exhaust. I probably would have overlooked any one of the problems if it had not done all of them.

    As I ran it at full throttle, no load, you could here a faint popping in the exhaust, not a backfire or anything just a random pop here and there. No real frequency to it. Kinda pop..pop.......pop......pop.. pop..pop..pop. Sorry, that's the only way I can describe it, LOL :)

    Today, the mower seemed to run ok, but the stumble showed up again. Once again, making a turn, it kind of fell on it's face. Anyway, the MIL is only lit brightly before the engine is started. Once running it goes dim. I guess that is normal???

    The mower has not picked a very good time to do this, my other ZTR is down too. May have to take the Grasshopper out of mothballs.
     
  2. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Keith:

    There are several things that could be going on here, but the only way to know for sure is to have a qualified mechanic look at it. Here are just some of the things that could be going on here. There could be a problem with the Throttle Position Sensor (TPS). You could have a bad oxygen sensor. You could have a cracked muffler. If your muffler is cracked, it will cause the oxygen sensor to get an inaccurate reading and make the engine run rough. You really have to look the muffler over good because it doesn't take a very large crack to cause a problem.

    If the MIL light is very dim, several things could be wrong, but I would do this. Sometimes when the MIL light is dim, that indicates that the terminals on the relay need to be cleaned. They are supposed to be self-cleaning, but sometimes they get a little corroded. Turn the key on without starting the engine. With the park brake on, move the drive lever in towards you and away from you. When you do this, you should hear a click from the relay. I would do this about 20 times. Now repeat this process for the other drive lever. This should help clean the terminals on that relay.

    Remember that the reason the MIL is dim could also be tied to the problem you are having with the engine. Check the muffler for any cracks (even small ones) and cycle the drive levers. If you have no cracks in the muffler, you need to get that mower into the shop.

    Let me know what happens here.

    Dustin
    Exmark Customer Support
     
  3. Keith

    Keith LawnSite Gold Member
    Posts: 3,977

    So the MIL should never be on, except before starting? Hmmm, like I said, it is nice and bright when Key On- Engine Off, but goes dim when Key on-Engine On. Not only does it do that now, it did it the day I picked it up and ever since. I could not find anything in the manuals referring to the MIL being lit other than "when lit, there's something wrong." I figured the dim lit MIL meant it had power to the ecm (or whatever they call it) and a bright MIL meant there was an actual malfunction.

    Thanks
     
  4. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Keith:

    When you turn the key on, it should be red. When you start the mower, it should go off. The Operator's Manual states, "If a problem or fault within the system is detected, the malfunction indicator light (MIL) is illuminated. . .Follow the troubleshooting steps outlined in the Kohler engine operator's manual if the MIL is illuminated." Let me know if you have any other questions, but it sounds like we have to have someone look at this.

    Dustin
    Exmark Customer Support
     
  5. Keith

    Keith LawnSite Gold Member
    Posts: 3,977

    It never goes completely off, just dim. You can understand why this confused me since it has always done that. You can verify that the light can go off, dim and bright, correct? The only time it is ever off is when the key is actually in the off position. I have also noticed it is using quite a bit of fuel. It sucked through one tank in about 3 hours according to the hour meter, which seems more than usual. Today I also notice two oil leaks. One at the crank seal and another on the cover.

    Keith

    BTW, how do they interface with the ECM on these mowers? Is it a stand alone real-time monitor, or is it Kohler hardware for use with a laptop or what? Does it monitor or just scan for trouble codes? Just my geek side wanting to know. I have AutoTap hardware and software for use with automobile OBD-II systems. I just wondered how this works.
     
  6. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Keith:

    The light should go off once you release the key. If the light is on, this indicates that service of the engine is required. The light is telling you that the computer has stored a fault code in its memory. Your dealer can access this fault code without any fancy software.

    Kohler has some diagnostic software that they load onto their laptops. They then hook their laptop up to the engine. They don't plug directly into the ECU. I think they plug into a relay on the machine. The software allows your laptop to monitor the voltage and critical engine components. If a code occurs, the software helps to troubleshoot the problem. I've heard mixed reviews from dealers regarding the success of this software.

    If you want more information, I would contact Kohler Engines. They'd be more than happy to provide you with all the information you need. Here is a link to their contact page - http://www.kohlerengines.com/contact.html. Let me know if you have any other questions.

    Dustin
    Exmark Customer Support
     
  7. MikeLT1Z28

    MikeLT1Z28 LawnSite Bronze Member
    Posts: 1,732

    sounds to me like only one cylinder is firing, but if you are having the MIL light come on, may be more than something simple.
     
  8. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Keith:

    One more thing. . .I never asked you for the serial number of this machine, so we don't know how old it is. If this is a newer model, some of the troubleshooting tips that I gave you may not do you much good. This is why troubleshooting via the Internet is so much fun!

    Here's an example. Cycling the drive levers in and out will probably not help you if the serial number of your machine is above 252,000. We made a change to that relay after the 252,000 serial break and that took care of the problem.

    Also, if you have a unit with a plastic case ECU, the MIL light will appear very dim when the unit is running. This change occurred when we switched from the metal ECU to the plastic ECU, so it is possible that you see a little light from the MIL.

    The bottom line here is that we need to have a professional look at this machine. Let's get your EFI back to the dealer, and they can see what's going on here.

    Thanks,

    Dustin
     
  9. Keith

    Keith LawnSite Gold Member
    Posts: 3,977

    It's fairly new :) About two months old. The serial # is 393788. I will get it back to the dealer as soon as I can, but it's my only ZTR right this second. My Kees cut a hydro cooler loose, the Grasshopper will need a few finishing touches to get it back in cutting shape. The dealer is an hour away at best, so since I can't just run it over for them to look at, I will need something else going.

    BTW, Here's a picture of, what looks like, an oil leak. Not sure if it I can attach a pic or not.

    kohler leak 2.jpg
     

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