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Thread: 09 XB12X idle issues

  1. #1
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    09 XB12X idle issues

    I am GREEN to all this so please forgive. New to "working on" motorcycles and only worked on car engines when necessary. Have a brother that's the mechanic who has owned Buell's for 14 years. He will be assisting when he can. So here goes.

    I just bought a 09 XB12X. 55000 miles. All stock from what we can tell except for K&N air filter and ECM. Came with a Buelltooth (no idea what previous owner did to tuning). Had a high idle (avg 1600 rpm) and wanted to stall out when stopped at every intersection after riding for a couple minutes on the way home.

    What I've done so far.

    Loaded a stock tune for a baseline since it has a stock exhaust. After loading the idle came down to an avg of 1300 rpm. CEL came on immediately after loading with an ACM stuck open code. My understanding after reading is this has no significance to normal operations except for mid band power.

    Replaced spark plugs. front was fouled but found a pinched breather tube because it was routed around the wrong side of head.

    Checked AFV via ECMdroid and had around a 90. Which I understand to be lean. If anyone can direct me to somewhere that describe what the numbers in ECMdroid mean would be SOOOOOO helpful. Anyway.

    Where should I start next? All help is much appreciated. Thanks in advance.

  2. #2
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    I would start by checking for an air leak on the intake manifold to head junction.

  3. #3
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    I did spray it the other day and noticed no change, but I also read after I did test that the engine should be hot. Mine was right after start up. I seen a video of someone doing a test were they stated the idle did change but I could not here the difference. Maybe untrained ears.

    I will be checking again today when its hot. I also have some help coming to help with some diagnostics later today.

  4. #4
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    I would retry that test with a warm motor. If there is fuel enrichment kicking in, it may mask the test results.

    As I understand it, the AFV only comes into play when you are riding along. I am not a master of tuning, so take that with a grain of salt.

    Also, you may want to reset your TPS and double check your O2 sensor or it could be you have a leaky injector.

  5. #5
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    I re tested for intake leaks when warm and no idle change. Think I can rule that out. Used ECMdroid and bypassed close loop. Disconnected cable for the AMC since it wont actuate, leaving the valve in the exhaust open. Ran great for my brother) at idle during and after a 5 mile ride. during my ride directly after his, idle issue showed back up. Re cleaned IAC, checked grounds (think I found all of them, 4?) ECMdroid live data shows IAC pos. changes(gets higher) when RPM drops. AFV has finally updated and reads 85.5%. Voltage also drops from roughly 14.5 to 13.2 when RPMs drop. We did find the ECM has a crack in the seal around the connector. Will post photos.

    Then we let bike idle for about 20 mins and the drop in RPM and sputtering is completely random.

    ecm1.jpgecm1.jpg

  6. #6
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    Iím Jacob Stark, Follow my post on Facebook. Iíll repost it here for reference. But please please donít get pulled too far away from the direction I sent you. Even if I didnít get it right Iím confident I can advise you through the process in figuring it out.

    ď So letís clear a few things up, first off donít disable closed loop, itís a good thing, especially when trying to diagnose an issue. Next AFV works like this, below 100 it is taking fuel away because it is seeing a RICH (not enough air, itís not measuring fuel, itís measuring oxygen) so at 90 it has made a Global correction of -10%. Anything over 100 indicates Lean (too much oxygen) so it will add.
    So if the AFV went to 85, you never successfully disabled closed loop, and it has removed 15% because of incorrect fueling in the cruise/closed loop area.
    To address your idle issue, itís increasing just above normal. The ECM does this when you put it in gear, or pull in the clutch anticipating you to be taking off. It determines this by the neutral switch, and the clutch switch. If the clutch switch is bypassed it can cause this, and a poor ground at your neutral switch will cause this. Remove the neutral switch clean the oil off and reinstall. Or you can test it by grounding out the wire to the switch, watch the light while doing this, if it gets bright, you know you had a bad ground at the switch.Ē

  7. #7
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    Interesting, I did not know that about the clutch switch affecting the idle speed.

  8. #8
    Senior Member Cooter's Avatar
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    Ya, Crash is right. I have found a way too tight clutch adjustment would raise the idle slightly (only on some bikes though?) because the clutch lever would be pulled and dis-engage the clutch without clicking the switch.

    A bad switch or open circuit would do the same.

  9. #9
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    Quote Originally Posted by Cooter View Post
    Ya, Crash is right. I have found a way too tight clutch adjustment would raise the idle slightly (only on some bikes though?) because the clutch lever would be pulled and dis-engage the clutch without clicking the switch.

    A bad switch or open circuit would do the same.
    My incorrect assumption was that the sole purpose of the clutch switch was to prevent the starter from engaging when in gear while on the side stand.

  10. #10
    Senior Member Cooter's Avatar
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    Thats what happens when engineers get bored. They just keep adding 'features' Haha.

    I have to rent cars all the time, and I can barely drive a new car sometimes. The 'features' are so silly. Rotary shifters, massive electronic 'keys', auto stop, and they ALL make noise, DONG, bing bing bing, whoop whoop! So Lame.

    Give me a small metal key, a shifter I can rest my hand on, a steering wheel, and BUTTONS. REAL BUTTONS I CAN FEEL, not some giant screen I have to look at while I'm supposed to be driving!


    Ahhhh, I feel better now



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