2006 Dyna Electrical problem/eratic idle

Discussion in 'Dyna Models' started by WideGlideDavo, Aug 2, 2011.

  1. WideGlideDavo

    WideGlideDavo Member

    43
    0
    0
    What started as what I thought was a fuel pak problem has turned into a nightmare. My 06 WG started dying when I stopped. Key on and off and it would start and run fine. Cleaned the IAC and that worked for about a week, then it started again. Replaced the IAC and now it starts fine but after a few minutes of running the idle creeps up and the engine light comes on. Local dealer recommended that I replace the eng temp sensor. Did that and no change. I do not have the electrical manual (5-7 days from the dealer) so I'm winging it at the moment. One thing I did determine is that something is telling the IAC to open up all the way and that is where it stays. Even when I key off it does not move thus the high idle, I think. If I unplug and reconnect the IAC it is functions fine. (Opens and closes) Until I start the bike again. So the IAC has 4 wires and is feed by the ECM from what I can tell. What is telling it to open and stay open? Fuel Pak has been removed from the bike so I'm back to stock ECM settings. I have no intake leaks per the propane test. And no codes. Just looking for a little direction until the Elect. manual gets here or I cave and haul it to the dealer.
     
  2. dbmg

    dbmg Experienced Member

    5,800
    153
    318
    Just a thought ... Have you checked to make sure battery cables are clean and secure on both ends??? If voltage not correct you can have many headaches.:)
     
  3. WideGlideDavo

    WideGlideDavo Member

    43
    0
    0
    Cleaned the cables and the cam position sensor which was clean to start with. No change. Bike starts, runs fine for a 5 min or so then starts loading up until the engine light comes on. If I rev it a few times it may or may not return to the correct idle. I aslo checked for intake leaks using WD-40 instead of propane. No leaks detected. I should have my electrical manual in 6 more days. :( I may go ahead a replace the MAP sensor just for kicks.........
     
  4. dbmg

    dbmg Experienced Member

    5,800
    153
    318
  5. WideGlideDavo

    WideGlideDavo Member

    43
    0
    0
    Thanks! But I've already been through that list. No codes to pull. What I would like to know is what feeds the IAC? Something is telling it to open and stay open thus the high idle. Wiring diagram shows all four wires coming from the ECM but I don't know whats feeding the ECM first? The MAP sensor and Throttle body temp sensor is all thats left that I've not touched except for the ECM.
     
  6. TripleJ

    TripleJ Senior Member

    1,081
    48
    8
    I have no wiring diagrams for your bike but I believe you will find that the MAP, IAT (Idle Air Temp Sensor), ET (Engine Temp Sensor), TP (Throttle Position Sensor) and VSS (Vehicle Speed Sensor) will all play a part in telling the IAC what to do.

    Even though you replaced the ET Sensor you still need to verify the rest of the circuit is working correctly. You also mention a Throttle Body Temp Sensor but I am not sure you did not mean one of the above as I am not familiar with that term used on an HD.

    My manual states that "The IAT, ET, and TP sensors are used to provide info. to the ECM to fine tune spark and fuel delivery. The VSS is used as an input signal for idle speed control".

    I would start by removing the VSS located on top of the trans. and cleaning any debris and reinstall. If that does not help I would wait until your manual arrives and start checking all the circuits according to the manual.
     
  7. WideGlideDavo

    WideGlideDavo Member

    43
    0
    0
    Thanks TripleJ, that info helps. Throttle body temp sensor was meant to be Idle Air Temp. My bad. You mentioned the VSS. The bike has the problem in static state. Does the VSS output when not moving? Easy to get to. I will look at it tonight.
     
  8. TripleJ

    TripleJ Senior Member

    1,081
    48
    8
    Anytime the ignition switch is on the ECM is powering and/or looking at the various sensors. The manual for my bike shows the VSS gets +5V from the same source that feeds the MAP, TP and Jiffy Stand. Not sure about yours just using mine as a reference.

    The output of the VSS will vary on my bike from 0-5 Volts. The manual will give detailed procedures for checking the operation of the VSS by checking resistance and voltages then giving solutions based on the info you find. Wish I could be more help but telling you what my manual suggest my be running you in circles.
     
  9. WideGlideDavo

    WideGlideDavo Member

    43
    0
    0
    Removed the VSS tonight. It was very clean, no debris. Wiped it off and reinstalled it. No change. I'll pull it again and ohm it once I get the manual.
     
  10. TripleJ

    TripleJ Senior Member

    1,081
    48
    8
    Don't forget to post your findings. I am interested to see what turns out to be the fix. I think it is a smart move on your part waiting on the manual, replacing parts can get expensive :D