Intermittent Miss

Discussion in 'General Harley Davidson Topic' started by Jennmarr, Jul 8, 2013.

  1. Jennmarr

    Jennmarr Junior Member

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    Hi guys, I have not commented here much, but I read a lot of what is said. My wife and I just got home yesterday from a trip through a few of the western states (Indiana to California and back). We rode a little over 7,200 miles in 25 days. About halfway through the trip the bike started to miss occasionally, and got got progressively worse throughout. I tried to identify any conditions that exacerbated the miss, but is seems pretty random. It will run fine for a while and then miss a few times in quick succession and then be fine for a period of time again. It seems to be slightly more frequent when the ambient temperature is lower (mid 80's rather than 100+). The bike is a 2007 Ultra with 115,000 miles on the clock. Engine mods are a Rinehart True Dual exhaust system and a Screamin' Eagle intake. Stage one download on the ECM. I bought the bike used (4,800 miles) and all the mods were installed before the 10,000 mile mark. Any thoughts?
     
  2. dbmg

    dbmg Experienced Member

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    Have you tryed spraying misted water on the plugs, wires, and coils to duplicate concern. Then check all connection to ecm and added assecories.
     
  3. Jennmarr

    Jennmarr Junior Member

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    I have not tried anything yet. We just got home last night and I am back at work now. I was looking for a starting point. I am a little confused about why I would spray water on the electrical system though. The miss occurred in completely dry conditions. Additionally, I should add that the miss never occurred at idle. It only happened at speed, and then only during acceleration or cruise. Never happened while decelerating.
     
  4. Jack Klarich

    Jack Klarich Expert Member

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  5. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    You might try starting with a good cleaning of the IAC, idle air control and checking the CPS, cam position sensor, to see if there is any build up on the sensor.
     
  6. Jennmarr

    Jennmarr Junior Member

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    Tank, I thought of that, but the fuel level does not seem to have any impact. I also left the fuel cap off and turned the ignition on and listened for fuel spraying inside the tank. I know that does not completely rule out a pin hole, but it leads me to think the issue is elsewhere. If it was a carbureted engine, I would say there was dirt in the float bowl. I will run the diagnostics as suggested when I get home from work this evening.
     
  7. Jennmarr

    Jennmarr Junior Member

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    That might be a good idea. The fuel filter has 115,000 miles on it.
     
  8. Jennmarr

    Jennmarr Junior Member

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    Jack, I ran the diagnostics per the instructions in the link you posted. There were no codes recorded in any module. The P/Ns that displayed were as follows:
    P-34411-07
    S-68924-07
    SP-67349-04a
    t-67348-04b
    Does any of that mean anything to you?
     
  9. Jack Klarich

    Jack Klarich Expert Member

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    My understanding is these are just part numbers or the modules that were checked, I could be wrong on this one, hope fully Hoople will have a better answer for you on this one
     
  10. dbmg

    dbmg Experienced Member

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    By misting the plugs and wires if they were breaking down during misfire, the water could duplicate concern and give you direction. Especially if one of the plug wires were leaking down at time of misfire. You have stated, misfire happened on acceleration.....