TFI Connections?

Discussion in 'Engine, Fuel and Exhaust' started by glenalt, Nov 8, 2009.

  1. glenalt

    glenalt Junior Member

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    I installed a TFI a few weeks back and upon initial riding I thought it was OK and I haven't ridden much due to weather but today was so nice I went out and it doesn't seem to accelerate as smoothly as is did before. It's just a little rough. I'm wondering if I have the TFI hooked up to the correct injectors. When I did it the instructions did not have the same colors like my bike has and I just guessed at it. If I do have them reversed how bad would the bike run?
     
  2. Breeze3at

    Breeze3at Well-Known Member

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    Glenalt; Glider and some others did a discussion of this a couple of weeks ago, and there is a front and rear connector. Try some searches or search tips.
     
  3. martin14

    martin14 Active Member

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    Noticeably bad enough to try swapping them.
     
  4. glenalt

    glenalt Junior Member

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    Thanks, I did read them when I initially hooked it up. Still couldn't figure it out but will look again.
     
  5. glider

    glider Veteran Member

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    Injector wiring colors are...
    Front injector...Yellow/green stripe & White/Yellow stripe
    Rear injector....Yellow/green stripe & Green/gray stripe
     
  6. glens

    glens Banned

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    Like a carbed bike! Hahaha!

    Seriously, how long would it take you to swap the bike's harness feeds between the TFI counterparts, leaving the injector-proper connectors alone, for a test run? Maybe it'd be easier to swap only the connectors directly on the injectors? I'd think you'd think things were clearly the opposite of an improvement if you'd got the signals mixed up. One combination will noticeably differ from the other. Maybe not so much at idle, but certainly while running through the gears one combination will be clearly better than the other.

    I just looked at a couple manuals at their site and they're quite clear that it doesn't matter which order things are done in, but no mention of any special considerations. From what I can see of the photos of the unit, I'd think each pair of leads was a male/female for an injector. If that's the case and they're not cross-connected, it really shouldn't matter one iota which male/female pair went to which injector.

    All it's doing is taking an injector signal and multiplying its duration by whatever factor is called-for at the time, then passing it along. If you cross-connected them, you'd have the injectors firing on the power strokes instead of the intake strokes. And the native fueling would pertain to the opposite cylinder. The cylinders don't have the same fuel curves as each other, so there would be some incorrectness in the base amount of fuel being delivered to each cylinder. That, coupled with the fuel being sprayed toward a closed intake valve would cause loss of atomization and possibly robbing of that present fuel by the other cylinder, since they share a common tract. It should run, but not nearly so well as it could.

    Seems their instructions would be a little more verbose about this.
     
    Last edited by a moderator: Nov 9, 2009
  7. glenalt

    glenalt Junior Member

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    I've got some time tomorrow evening and will swap them and see. I'll let ya'all know.
    Thanks for the suggestions.
     
  8. glenalt

    glenalt Junior Member

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    I've been real busy and out of town. Off today and checked my connections they were correct. I called Chris and at Dobeck and he it makes no difference which of their connectors goes to which injector as long as you keep the injector from the factory that goes to the front and rear injectors in the same location. Their unit doesn't care.

    We discussed my settings and I must admit I feel a little dumb. He told me the numerical values for the settings did not match the numerical position on the unit but represented the positions on a clock. On my unit they are not the same. I made the corrections and WOW what a difference. No more running too rich and lots a power.

    Thanks for the input guys.