5th gen intermittently dies, flipping kill switch resets. Help!

Discussion in 'Mechanics Garage' started by rudolfs001, Jun 19, 2021.

  1. rudolfs001

    rudolfs001 New Member

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    1999 VFR800 with 133k miles, motor has ~65k miles, been dropped.

    Symptoms:
    While riding, bike will intermittently and suddenly lose all engine power, tach goes to 0, FI light comes on (all other electronics stay on, speedo works, etc.). Toggling the kill switch will restart the bike and tach. FI light will go away after a couple seconds.

    Sometimes this will happen after 30 miles, sometimes it will happen after 1 mile. It appears to happen more frequently above 6k RPM/85 mph.

    Diagnostics attempted:
    Traced and visually inspected electric wires = no obvious faults

    Disconnected and bypassed tip over sensor (connecting pins 1 and 3) = issue still occurs

    Tested kickstand kill switch in 1st at standstill = stops bike, but doesn't turn on FI light

    Relevant mods:
    Rectifier replaced
    VFRness
    TFI fuel controller

    I'm out of ideas on what to try next, short of a new ECU. Any recommendations?
     
  2. RllwJoe

    RllwJoe Insider

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    You may want to dismantle the kill switch and clean the internal contacts. If you bump the kill switch inadvertantly while riding the result sounds exactly the same as those you have discribed.

    Do you use the kill switch to stop the engine on a regular basis, or do you use the ignition switch?

    On a side note, many have found that the VFRness is not required. The R/R has only a positive and negitive output connection, and they can be connected directly to the battery thereby bypassing the wiring harness altogether typically using 10 gage wire and a 30 amp fuse inline on the positive wire. That is what I have done without problem the last three and a half years and approx 15,000 miles.
     
  3. raYzerman

    raYzerman Member

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    If all above is OK and it still happens, I'd unplug the TFI, reconnect stock, and see if it's an issue then.
    I'd also verify the chassis ground and the orange ground spider are clean and good.
     
  4. rudolfs001

    rudolfs001 New Member

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    Dismantled and cleaned, issue persists. The result is exactly the same as toggling the killswitch, though I don't believe it's caused by anything in the killswitch housing.

    I do use it to stop the engine, and have on all bikes I've owned.

    BTW I've only had the VFR since 131k miles.
     
  5. rudolfs001

    rudolfs001 New Member

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    Where is the orange ground spider located?
     
  6. tirso

    tirso New Member

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    Recently someone had similar issue on VFRD.
    https://www.vfrdiscussion.com/index.php?/forums/topic/98620-frustrating-stalling-problem/
    Reading the thread may help you.
    On a 5th Gen, the orange ground spider is located on the the left side, under rear cowl, above the chainguard, wrapped in tape.
    You can unravel the tape finding the end on the right side of the block.
    The next place to look is the 30 amp fuse next to the starter relay in front of the battery tray.
    It's a bit tight in there and you have to be careful on releasing the white fuse holder that's held to the battery tray by a clip.
    In the above thread there's a picture of the white fuse holder and you can see the clip to release.
    When I cleaned my a few months ago, it was easier to remove the battery.
    Remember to also clean the connections to the starter relay.
    Really bad things can happen to your electrical system if any of the above are dirty.
    Ox-guard is your friend.
    Good luck!
     
  7. Grum

    Grum New Member

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    Your Kill Switch performs two functions. It will lockout your Starter circuit AND it will cause the Engine Stop Relay to de-energise, instantly stopping your bike.
    Generally speaking if you are not having issues cranking your engine over then that means your Kill Switch should be O.K.
    Your Fi Light being fully on means it has detected an Active Fault OR it has lost power, or a major Ground.

    Closely check the state of your Main Fuses being 30amp. Check for overheated contacts and wiring for the fuses. You need to be sure that with Ignition to On you are seeing a solid 12v for the Engine Stop Relay coil via the Kill Switch on the Black wire. With the relay removed measure this voltage and be sure EVERY time you operate the Kill Switch the voltage comes and goes with the switch operation.
    Check that the Green Ground wire for the Bank Angle Sensor, is properly bonded to ground, that means it measures zero ohms back to the battery Negative terminal.
    Make sure you measure a solid 12v at the Engine Stop Relay Black/Pink wire with Ignition to OFF and then you measure 12v on the Black/White wire with Ignition to ON. Relay Installed!
    If you have any suspicion regards the Engine Stop Relay you could swap it with your known good HiBeam relay to isolate it.
    Good Luck.
     
  8. rudolfs001

    rudolfs001 New Member

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    SOLVED

    I wasn't able to find an orange ground connector anywhere on the rear of the bike. While poking around, I found the FI code diagnostic connector, which I didn't realize the bike had.

    Checking the codes, it had FI 11, 13, 14. The first is a loose speedo connection, which I've never had an issue with. The latter two are for loose connections to fuel injectors for cylinders 2 and 3, with a fail state of bike not running.

    After unplugging the fuel injector connections at the cylinder, spraying some electrical connector cleaner, and replugginz them, I've ridden about 150 problem-free miles!
     
  9. raYzerman

    raYzerman Member

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    The injectors and coils share a common ground coming from the ECU.... which receives its ground from the chassis ground on the right side of the frame. Check, clean and reinstall.
    What's not on the diagram is the orange ground spider.... it is taped into the harness, so look for a suspicious lump and carefully untape it to expose it. Might be your speedo issue.
     
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