RPM at start up

Discussion in 'Touring Models' started by Cuzz, Mar 29, 2012.

  1. Cuzz

    Cuzz Member

    49
    0
    0
    Seems not to be my week. First it was a nuisance burned out bulb, no biggy, but now something more interesting. Since new... when I start the engine the RPM junps up to 1200-1300 RPM or close to that. It settles down to a normal idle speed within 5 seconds roughly. While riding yesterday, the bike shook and began running rough. I did not know what it was, but I had normal oil pressure and the oil temp gauge was OK too. Long story short, I rode about 10 miles (slowly) with the ignition wire off of the front cylinder. That plug wire fits tight, but I'll hold off on the sabotage theory for now. Now with both cylinders getting fire, when I hit the starter the engine revs up to 2500 - 2600 RPM, and it takes at least twice as long to settle down. Does the ECM have to relearn something or???? any ideas?
     
  2. Jack Klarich

    Jack Klarich Expert Member

    18,544
    153
    399
    http://www.hdtalking.com/archive/t-2362.html Run the codes for starters:s
     
  3. Cuzz

    Cuzz Member

    49
    0
    0
    Jack,

    Got a P0131 front oxygen sensor low code.
     
  4. Hoople

    Hoople Account Removed

    7,198
    0
    34
    P0131, Front cylinder running lean. Probably has little to do with your current idle problem. That DTC could be caused by an exhaust leak also.

    For your idle RPM problem, the first thing I would do is flush the IAC and see if it makes a change to the good side. 2500 RPM are a lot of IAC steps.
    Sounds like the unit is not parking completely and when you reboot or start the bike, the stepper motor sees a bind (thinks it is the park position) and counts from that point out which puts you at the 2500 RPM range.
     
  5. Cuzz

    Cuzz Member

    49
    0
    0
    Hoople,

    Thanks for the feedback. I hear what you're saying, but I cant help thinking that running without the front cylinder firing is somehow part of the reason. I made several stops and restarts during my trip yesterday and it fired up normally every time. I do not know what flushing the IAC means, so perhaps that was your solution. If you have some details with respect to this flushing process, please advise. thanks-a-heap!
     
  6. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    5,456
    133
    196
  7. Hoople

    Hoople Account Removed

    7,198
    0
    34
    There isn't any relearning process that I know of. Just clear the code yourself and see if it comes back. You did not mention what type of fuel enrichment system you have on the bike or if it is stock. You can do the IAC flush but if the bike now runs normal and settles quickly with the proper idle speed, I would just ride it. There's no telling what strange things can happen when 30 thousand volts is looking for a ground path. Then in a couple of hundred miles of riding, check for that reappearing lean code. That code has a much better chance of setting during steady state cruise speeds (30%-70% of throttle).
     
  8. dbmg

    dbmg Experienced Member

    5,800
    153
    318
    Why not first try to reset idle set reference. Be sure run switch is off. Turn ign on. Then turn run switch on and let fuel pump prime and wait till check engine light goes off. Then turn off ignition. And turn run switch off. Do this 3 more times and there is a good chance that the idle set reference will reset to 1000 RPM.