Anyone kept the O2 sensors/closed loop with Rotti intake & full exhaust?

Discussion in 'Hard. Core. (1090/1190/1290)' started by achalatsis, Jan 18, 2019.

  1. achalatsis

    achalatsis Been here awhile

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    Hi all,

    I've read pretty much all related topics but I still think this can go on its own, new one.

    After about 100k km on the bike :p, I've decided it's time for a change and want to go back to having a proper closed loop and reinstalled the lambda sensors (removed the dongles).

    The setup works pretty well and as expected, with only one issue. Trigger conditions:
    * 0-5% throttle, usually it's around 2.
    * low rpms - between 2500 and 3800-3900.
    * very low to no engine load. Example condition: rolling downhill and you barely open the throttle - the moment everything syncs and you're neither engine braking nor actually pulling on motor power.

    Then, the bike messes up and chokes into a very lean state (I can see between 15 and 16.5 in my afr gauge) and stutters. Back off the throttle or give it more (even a bit, i.e. maintain closed loop operation) and it gets its act together.

    I know I can't really do much at this point. I'm more interested if anyone else has managed to have a working CL setup and what hickups they've had.

    I'll try and upload an example video soon.
    #1
    kostasdirt, ADV-wannabe and Whiteyez like this.
  2. opanos

    opanos Been here awhile

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    this can occur due to cpu/ecu precision issue. When you slighly open your throttle, ecu may see that opening as a zero throttle imput due to lower sensitivity level than your imput. Basic AD stuff.

    If that's true, for a predetermined fuel amount, you are adding air through that small throttle opening, resulting in a lean engine condition. Maybe it could be fixed if you richen up the map on that particular area. It could work because lambda sensors do not make huge fuel corrections and always rely on the base map.

    But in any case, since you have a wb sensor, you should better make a completely custom map of both cylinders and get rid of those narrowband sensors. Closed look function is overrated, when a narrowband sensor is used.
    #2
  3. achalatsis

    achalatsis Been here awhile

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    Γεια σου ρε Pumba! :D

    It's registering as throttle input as I'm monitoring the TPS voltage through PCV and I can see the change(hence the 2-5% throttle above). I don't think that this would fall below ecu's threshold. But, in case it does, it probably means I can work it through the pcv and the ecu won't care!

    That does sound logical, as because of the modified intake I'm letting more air in, and in general I see the CL to be slow in its reactions. And it does catchup eventually (if I let it choke for a second or two).

    I can't actually change anything with the sensors in place as pcv will get into a fight with stock ecu. Ideally that's what I will do when I get rid of the pcv and remap the stock ecu.

    I do have a custom map - erased it in the closed loop area to see how the bike is working with the sensors. I don't like how the tricked CL with the dongles works - it does never work the same on the greatly varying conditions you'll experience on a long-distance trip.
    #3
  4. brianbrannon

    brianbrannon They'll ride up with wear

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    It's not an easy task but try syncing your throttles
    #4
    TakSD likes this.
  5. geez996

    geez996 Been here awhile

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    :lurk
    #5
  6. Bluesilver

    Bluesilver Long timer

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    Run with and without using autotune and it is rubbish with the stock sensors in, transition between closed loop and custom map is far to different.

    Fit the dongles and enjoy the smooth transition.

    imho
    #6