Possible problem with dobeck tfi tuner?

Discussion in 'General Harley Davidson Topic' started by Ultra Classic, Jul 2, 2014.

  1. Ultra Classic

    Ultra Classic Member

    Hello. I having a problem with my 2011 ultra classic and could use a little advise. I'll set the background to give a little information on what the bike is doing. I have a stage 1 set up. Screaming eagle slip on exhaust, screaming eagle air filter, headers with catalytic converter removed by American custom, and Dobeck TFI tuner. Bike has only 11,000 miles on it and i have had this set up for over a year now with no problems until now. I was at a red light idling and when i started to slighly roll on the throttle the bike felt as though it wanted to stall. Now i've been noticing the problem when i shift gears to get up to speed it tends to do the same thing when i roll on the throttle. Now my question is why would this be happening now when i have had this set up for a long time now? Could the tuner get out of whack after a while and just need slight adjustments from time to time or is there and underlying problem? I was thinking that this weekend i would adjust the tuner again to see if it solves the problem. If that doesn't work I was going to change the bike back to stock to see if it still has the same problem. I know that if i take it to the harley shop they are just going to say the problem is with the tuner or is this what i should be doing? Thankyou for any advise you can give. Chris
  2. 34thestickupkid

    34thestickupkid Active Member

    Let us know what happen when you went back to stock sittings,,
  3. tourbox

    tourbox Senior Member

    Have you checked for any codes with the diagnostic feature?
  4. RibEye

    RibEye Junior Member

    Such issues are tricky to nail down. I would check 2 things as a start:
    1. Take her to where they can check your fuel rail pressure. A hole in the inside-the-tank fuel line, due to rubbing.
    2. A break in the injector wiring, inside the insulation, up near the injectors, due to vibration and incorrect/insufficent service loop.

    Good luck,
    Rich P
  5. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    Check for codes that Tourbox suggests first. It will give you some indication of the issue if it has codes stored.

    Unhook the tuner and run it temporarily to see if it solves the problem. Used to be you could lift the ground wire on the tuner and it would disable it. Not sure about your model tuner if that works or not. That is what I would do to rule in or out the tuner.
  6. Breeze3at

    Breeze3at Well-Known Member

    I think you have a problem with the throttle position sensor. There have been many reports (and service bulletins) about corroding pins in the connector, as well as the sensor itself. In my memory (faulty at best) TFI's either work, or don't.
  7. RibEye

    RibEye Junior Member

    Depending on model, lifting the ground could show if the Dobeck electronics are a cause. However, if the problem is in the injector wires (internal break), lifting the ground will not correct it (Don't ask how i know). Dobeck circuitry is usually quite reliable. If you want ot eliminate the Dobeck as a cause, you will have to bypass it (remove it from the circuit, and plug the original injector connectors tot the injectors.

    I would check the fuel rail pressure, just for a simple and quick sanity check. The other suggestions may lead to an anser too. They will cost a bit to eliminate.

    Rich P
  8. Dr. Dolittle

    Dr. Dolittle Experienced Member Contributor Retired Moderators

    1. Check for codes
    2. Which model TFI and what are your current settings?
    3. Have you done any other recent mods or maintenance?
    4. Did you recently switch brands or octane of gas?
    5. Clean the pins and apply dielectric grease where your ECM connects and the connector behind your air cleaner
  9. glazier

    glazier Junior Member

    I wouldn't think you need to do any tweaking to the TFI if you haven't done any mods since. To check if it is the TFI unit, just disconnect the ground wire and take it for a spin. Without the ground, you're just bypassing the TFI completely. That will at least tell you if thats where the problem is or if its something else.
  10. Ultra Classic

    Ultra Classic Member

    I really appreciate everyone's advise on this matter and will definetely checks those areas for problems. I'll keep this forum posted on my future findings.Thanks again.