Worst Ride Ever - Bike Tried To Kill Me!

Discussion in 'Engine, Fuel and Exhaust' started by Dr. Dolittle, Sep 9, 2013.

  1. Dr. Dolittle

    Dr. Dolittle Experienced Member Contributor Retired Moderators

    Long story but I'll try to give as many details as possible. Bike is an '08 FLHX with Stage I and GEN4 TFI.

    Embarked yesterday morning on the 2 hour ride up to Athens to meet my daughter for brunch. First 30 to 40 minutes were totally uneventful - bike running perfect.

    At a steady 65MPH in 6th gear with the cruise control engaged, the bike suddenly hesitated for a split second but went right back to running fine. Then it started doing it more frequently and actually kicked the cruise control off. I have the GEN4 AFR gauge mounted on my left handlebar and I noticed it was running in the steady green zone but the AFR was pegged full lean - 16 plus and not moving. I could vary the throttle and get it into the yellow and red zones but the AFR remained pegged.

    Since I hadn't ridden in a long time and was down to about 1/3 of a tank of gas, I suspected part of the problem may have been stale fuel and/or water in the fuel. I pulled into a gas station, topped off the tank, and even added some ethanol treatment.

    Got back on the highway and it started getting worse. I aborted the original mission and headed for home. Got to the point that I could barely hold 55MPH even though the TFI showed I was in the red, full throttle zone and I couldn't get the RPM above 3000. Closer to home it got so bad I was riding on the shoulder with emergency flashers on barely doing 20MPH.

    The last couple miles to my house is normal, non interstate roads. I barely made it home, having to feather the clutch like crazy moving out from every red light. The bike just had absolutely no oomph at all.

    Pulled the codes when I got home and got a P1353 and a P1356 - Front and Rear Cylinder No Combustion. Much internet research points to a lot of electrical culprits with these codes - coil, plugs, plug wires. But I'm also suspicious of the TFI showing such a lean AFR the whole time. Can it get so lean that the bike's computer interprets that as "no combustion?" Once it throws those codes, does it automatically put you in "limp" mode? That's what it felt like to me after reading the description from others.

    Bad thing is I'm not going to be able to begin trouble shooting this problem for another week. Just thought I'd throw it out on the forum and start getting ideas and advice.
  2. Rod Stewart

    Rod Stewart Active Member

    First suspect on my list would be the wiring where the TFI connects to the injectors. If this was wired so as to put any stress on the wires or connectors, chances are one or more wires has failed.
    I have been there twice now with TFI's.
    According to Dobeck this is the cause of 90% of their units failures, something over which they have no control.
    I would disconnect the TFI at the injector plugs and reconnect the HD connectors straight to the injectors, then try it out. This will tell the tale.

  3. Dr. Dolittle

    Dr. Dolittle Experienced Member Contributor Retired Moderators

    Thanks, Rod.

    I've also read, I think anyway, that disconnecting the TFI ground at the battery totally removes it from the loop and lets you determine if there's a problem with the actual TFI unit. I'll try that and your idea sometime next week when I get a few hours free.
  4. Jack Klarich

    Jack Klarich Guest

    :D That will be the quickest way of taking the TFI out of the loop, I know it is hard to get to the injector wires but I would have a wiggle test there too:s

    BUBBIE Well-Known Member


    Give Mark Dobeck a call... Have you tried it since the problem?

  6. GaBoy

    GaBoy Member

    I had this exact same thing happen to me last year on my trip to Sturgis. I was on my way from Milwaukee to Sturgis and got as far as Madison WI and found the dealer there. Turned out to be a broken wire on the Gen 4 going to the injectors. They fixed it for me and there have been no problems since.

    One other thing to add though, seems the hotter the motor got, the worse it was....
  7. Hoople

    Hoople Account Removed

    When using a wide band sensor to determine A/F ratio, a cylinder misfire will make or fool the A/F gauge to read a lean mixture when it really is not. That's perfectly normal. A misfire fools the wide band because an unburned cylinder charge is packed with oxygen molecules. It sees those oxygen molecules and moves the meter reading to lean side even though the unburned charge can be misunderstood as being a very rich charge of fuel.
  8. Dr. Dolittle

    Dr. Dolittle Experienced Member Contributor Retired Moderators

    OK, sounds like everything is pointing to something with the injectors.

    Jack, when I get to lay my hands on this next week, I'll try the wiggle test first thing.

    GaBoy - thanks for the input. And yes, it definitely got worse the longer I rode and, therefore, the hotter the motor got.

    Hoople - what you wrote pretty much makes sense to me. So you think something was wrong with the fuel delivery system and the TFI AFR gauge was reflecting this by displaying full lean?

    I have to admit I was initially leaning towards the TFI being the root cause of the problem. Now I plan on trouble shooting several other things before simply removing power and taking the TFI out of the loop.

    Hopefully I'll be back later next week with a successful outcome!
  9. Dr. Dolittle

    Dr. Dolittle Experienced Member Contributor Retired Moderators

    Parked it and haven't touched it since. Going to work soon and won't have a chance to mess with it until next Sunday or Monday at the earliest.

    I'll call Dobeck AFTER I do my trouble shooting and am certain the TFI is actually part of the problem.
  10. Jack Klarich

    Jack Klarich Guest

    :D Good luck Dr, it will be a learning experience here I am sure:s