Electrical issues, or fuel injector?

Discussion in 'Electrical' started by Springer43, Nov 19, 2008.

  1. Springer43

    Springer43 New Member

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    I ride a fuel injected 2006 Springer softtail - that has had a fair amount of cosmetic customization done to it. Other than lengthening some wiring, the electrical, motor and drivetrain remain completely stock. It has just under 12K miles on it since the customization and had been running fine up until the past 2 months. In fact, I rode it from Phoenix to Sturgis and back this past August. No issues to speak of over the 3K miles of the trip.

    Since most of the posts on this site seem to come from people with a lot of knowledge on the topic, I wanted to get your opinions on what possibly could be causing my issue. I know it’s a bit longwinded, but I wanted to make sure to give anyone reading this enough information so they could make educated guesses at the issue.


    Issue/Symptoms:
    While going down the road, I have an intermittent hesitation or miss. When I experience the hesitation, it also seems that it is huffing (best way I can describe it) through the intake because the air filter is getting black. It’ll be black within 200 miles of a recharge. I also have a lot of popping in the pipes under deceleration and occasionally even while travelling down the road. It also seems that the hesitation happens more at low to mid range RPMs and not as much at higher RPM ranges. Problem is not noticeable to the ear when the clutch is engaged and/or the motor is just idling.

    I should also mention that the initial start in the morning, the engine starts, and races up in RPMs right away then hesitates and dies unless I give it a twist of the throttle right away after starting. If it does die, I'll restart it immediately and it will stay running and seems to warm up normally after that. Not sure if that helps at all but wanted to throw out everything I can think of.

    Customization:
    Replaced the stock buttons with PM Contours - spliced in their wires to the HD wiring harness. The PM buttons leads are a different gauge wire (smaller) than the stock wires. Also, the leads are approximately 36" and I used all of that so I could run them internal in the handlebars. I did put a layer of heat shrink tubing over each pair of leads, then another over the 3 sets of wires before running them through the handlebars.
    Running SuperTrapp Crossover Shotguns pipes. - I tape wrapped them about 6 months ago in hopes of getting a bit better performance.
    Running the Stage 1 air cleaner with a K&N filter.
    HD EFI race tuner installed. Not sure which mappings if any were applied?


    Investigation:
    In starting my investigation, I thought it was maybe a break or short in the ignition wire from the buttons to the ECM. Since changing the buttons was one of the things I did during customization, I thought that this might be a good place to start. I did find a pinched wire, right where the wire bundle pass between the frame and the fork stop so I spliced the break out. I didn't find any other issues for the turn signal or the kill switch wires. I didn't use the exact same size wire when doing the splice but used something close. It's was only a 1" splice piece. The splice piece was 20 or 22 gauge wire.

    Result: No change.

    The second thing I checked after reading this forum was the gas line between the fuel pump and the petcock. Found that the clamp may have been a bit too tight, or the hose was too close to the end right by the fuel pump connection so there was a pin hole sized leak. I back it off about a 1/16" and tightened it appropriately. Doubled checked it for leaks before stuffing it back in the tank.

    Result: A little better. Fuel line maintains fuel and pressure better even after shutting off the bike but I am still feeling the hesitation.

    Another thing that was changed recently was the spark plugs. I changed them just prior to the Sturgis run. I double checked that they were properly gapped before the install and after about 100 miles of usage.

    Result: No change.

    Finally, after reading a lot of information on your forum, I checked the ECU codes.

    P - None
    S -b1021, b1022 - Not surprising since I don't run front turn signals.
    SP – b1004, b1005 – These also make sense since I got rid of the gas float and gas gauge.
    T - None



    A friend of mine, that's done a far bit of motor work in his past, mentioned that he thinks the bike is running lean (causes the popping on decel), and that I may have a fuel injector going bad??? I can accept that, but if that would be the case, wouldn't the ECU be calling attention to those items? Additionally, if I had an intermittent ground with the wiring, wouldn't the computer call attention to this as well?
     
  2. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Not going to try to quote back to your post, just some quick suggestions.

    Running lean. If you did not have the race tuner installed, and some of the mods (breather, pipes?) were done after that, the bike may be running lean. Would explain the popping. All factory issues will be lean, and some VERY lean. May want to consider remapping based on all the mods associated with the air pump system.

    On the popping: check for exhaust leaks, at the heads and at any clamps. Also check for intake leaks, although this may be more difficult to find since your problem does not sound that consistent (use the WD40 spray approach - be careful, the stuff is flammable).

    Make sure the wiring to the injectors has no breaks by wiggling each and seeing if you get any changes to how the engine is running.

    Dump some dry gas and injector cleaner in the tank for the next few fills. I know you had the tank open to fiddle with the fuel line, but not clear if you dumped the gas. If you are back in the tank for some reason, get a flashlight in there and make sure there is no water. Also, consider replacing the plastic fuel lines with something more robust.

    Let us know.

    TQ
     
  3. glider

    glider Veteran Member

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    Excellent post with all the info. That's the way to do it too.

    Things that came to mind as I was reading it were these.

    Fuel pump pressure, you found a problem there but how about testing it to see if it holds pressure?

    Cylinder head temp sending unit. You could verify this using the SERT to see if it is working properly.

    TPS setting, also verifiable with the SERT to see if it is set properly.

    Popping on decel could be exhaust leak or a lean setting as you mention. Cover the exhaust outlets tightly with gloves on while running and listen for a hissing in the system to verify a leak. You should be able to stall the engine if you hold it long enough. Also check for an intake system leak using some WD40 around the boots. A change in idle speed will indicate this.
     
  4. SeaRider04

    SeaRider04 Active Member

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    If something wrong with wiring (electrical/electronic) like open/shorted, then the ECU will picks it up and set a TDC but if wiring is ok and the problem is in the injector(mechanical) itself then the ECU would set a different code like "system lean/rich" depending on how injector was bad (stuck open/closed).

    ECU will not picks any mechanical failure, same as if your fuel pump is weaks, ECU "see" the voltage/signal going in/out but it's doesn't knows how much pressure/volume that the pump is pumping out. Just a though.
     
  5. Springer43

    Springer43 New Member

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    Thanks for the replies. I will try each of your suggestions. And let you know.

    I am not familiar with the WD40 test to check the intake. Where can I find more info on that?

    As for exhaust leaks, The cross-over shotguns are single piece pipes, so I don't think I have any leaks unless it's right at the head. I did try changing the metal pressure crush washers that go in the head. I made that change back in the March.

    I have a feeling that when the shop installed the pipes, air cleaner, SERT, they never put the bike on the dyno and mapped it out properly. I wouldn't put it past the HD dealership to cut corners to save a few bucks. Plus the good wrenches there never seem to stay that long. I have a sneaky suspicion the bike is running very, very lean. I thought there was also a way I could see this through visual inspection of the spark plugs? Does anyone now of to test or inspect for that?

    Thanks guys, hopefully at some point, I'll be able to return the favor.

    Springer43
     
  6. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Like Glider said above, the WD40 intake system leak test is simple. You may want to loosen up the gas tank and raise the back of the tank a bit to give yourself more room. Then fire up the bike and before it gets too hot, using the little red tube on your can of WD40, spray the intake manifold where you can see connections to verify that there is no leak there on the suction side of the air pump (the engine is just an air pump - of course some of the air is burning!!). If you have a leak, the WD40 will cause the engine to falter. Make sure you are not spraying so much WD40 around so as to have it sucked in the breather. Takes a bit of practice, but if you get a reaction from the engine, go at it from another angle spraying the same area to confirm. It is a quick simple test that can help find this type of leak. If you have one, strip off all the intake side and renew all the stuff that is supposed to seal the intake side!

    TQ
     
    Last edited: Nov 20, 2008
  7. glider

    glider Veteran Member

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  8. bwalsh22

    bwalsh22 Junior Member

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    They probably just downloaded the stage 1, no dyno time unless you paid for it. I have a stage 1 done, ECM went bad on mine, under warranty, had to give me a new SERT and all they did was above. I have popping on my decel. Till I get a laptop that I can install stuff on (work computer won't let me) I can't adjust the mixture and not quite ready to shell out the bucks for Dyno time.
     
  9. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    If it really bothers you, on a temporary basis you might pick up a TFI and use that to adjust the fuel mixture to smooth out the engine. For about what you would pay for dino at the Dealership, you will get a tool that will allow you to adjust the fuel mixture so it runs like you want it to.

    TQ
     
  10. bwalsh22

    bwalsh22 Junior Member

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    Thanks, I have considered it, just still debating it. So far I have learned to live with it and a laptop purchase is in the near future or an unlocked work laptop :)