Very Intermittent Problem With Ignition System?

Discussion in 'Engine, Fuel and Exhaust' started by SoonerSoftail, Dec 12, 2011.

  1. SoonerSoftail

    SoonerSoftail Active Member

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    In almost three years this has only happened twice so I'm not terribly concerned. Just curious.

    I turn on the main switch, turn on the run-off switch and hit the start button. The bike fires up but is running on just one cylinder, barely. I turn off the main switch, let it sit a few seconds, turn it back on and she fires right up and runs fine. Like I said earlier it did this once at a gas station (engine warm) about two years ago. It did it again in the driveway (engine cold) this morning. Any ideas?
     
  2. glider

    glider Veteran Member

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    Have you checked/replaced the plugs or plug wires?

    Take a compression test on both cylinders?

    Run some Marvel mystery oil in the engine oil to clean things up?

    Many possibilities on what it could be but you have to try a few things first to eliminate them as a source.
     
  3. SoonerSoftail

    SoonerSoftail Active Member

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    I did change to red SE wires about a year ago. So that would make it one time it did this with the old wires and once with the new. Cams about the same time so again once before and once after.

    I didn't think to when it did it the first time and didn't think any more about since it hasn't done it again until today.

    I do run SeaFoam through it every few tanks.

    Other than this two times she runs perfect. Also, it has approx. 24,000 miles. The first time it did it this had maybe 8,000. It had about 5,000 miles when I bought it. It had V&H LongShots and a Arlen Ness A/C when I bought it and it still does. It's had a PCV since about 6,000 miles.

    Also, there were no codes the first time. I haven't checked this time. But powering the main switch off and back on seemed to fix it both times. Sounding like something in the ECM to me.
     
  4. Hoople

    Hoople Account Removed

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    Don't just go by the check engine light, perform a WOW test. Next time it happens, see if you can keep it running for a bit & try to increase the RPM in order to force a code to post. You really should be logging a combustion code of some sort. It almost sounds like ignition phasing latched onto the wrong cylinder.

    Also, instead of turning off the ignition key (which re-boots the ECM), try turning off only the run/stop switch and then restarting. Don't turn off & turn on the ignition key. That keeps the ECM from rebooting and resetting the software which will clear almost anything that is spooky. Now if the problem clears up without an ECM reboot, it points more toward loosing ignition sync and phasing.
    What brand/model plug are you using.
     
  5. texas tom

    texas tom Active Member

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    How do you know its running on one cylinder? Are you sure its not simply gone into parade mode and as soon as you take off it wont go back to normal? The reason I say that is you say it does it when hot on a restart it could be that simple or could be a problem..good luck..Tom..
     
  6. Charlies Harley

    Charlies Harley Active Member

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    Had much the same thing happen some time back on my 06 heritage, as all things it got worse as time went on. In the end it turned out to the electrical conector to the rear injector wasn't on properly. Easy fix after down loading the codes and checking that system.
     
  7. SoonerSoftail

    SoonerSoftail Active Member

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    I checked for stored codes. None. I've tried to keep it running when it does this but it only runs for a couple of seconds no matter what I do. If it does it again I'll just use the run-off switch. Should have thought of that. And I'm using SE plugs.

    One cylinder not firing is a pretty obvious sound. And in this case it sounds like my old TT500 single cylinder dirt bike if it had had a halfway fouled plug. It did it once hot. The other time was yesterday morning in 40 degree weather right out of the garage. Heat isn't it.

    I'll check that.
     
  8. texas tom

    texas tom Active Member

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    Ok I see,the fact that turning it off for a few secs fixes it allmost reminds me of a problem I had with a 2000 chev pickup when the fuel pump started to go bad, if I cycled it off on a few times it would seem as if nothing was wrong.Not saying thats your problem but I would check the fuel system ,but it seems to me that a weak fuel pump would throw a code,try this for grins take fuel cap off turn ign on switch to run see if you hear something strange in your tank,possibly have a leak in the fuel hose inside of tank. Good luck keep us informed if you find something. Tom..
     
  9. Lawdog314

    Lawdog314 Active Member

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    Friends Heritage, older don't recall the year, acted the same way a couple of years ago. As I recall, it seemed run fine and then without warning, start breaking up and running as if it was on a single cylinder. He removed and replaced all the common suspects without luck.

    I know a tad about electrical, so I cleaned most every contact and especially grounds. Many had a little to way too much corrosion on them. When she was put back together it ran much better for the rest of the season. I say better because he still experienced misses once and a blue moon. He finished the season and sold it before we could do any in depth winter troubleshooting.

    May want to check your contacts over. Time consuming and not real fun. Recommend a ball game on the radio, and your favorite adult beverage in close reach. Good luck! :cheers
     
  10. SoonerSoftail

    SoonerSoftail Active Member

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    Thanks everyone. Most suggestions I've looked at. The others I'll do. But with it only happening twice in three years/19,000 miles it might be a long time before I know I found it, if ever.