How can I test Motronic 1.4

Discussion in 'GS Boxers' started by container, Jan 4, 2012.

  1. container

    container Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    72
    Location:
    Slovenia
    Apparently I might have bad Motronic 1.4 on my 2004 1150 RT-P. As I have wired everything up myself & beeing a noob, I still think there is strong possibility of something being wired wrong or missing at the harness.

    How do I check if my Motronic works. Other than swapping it or taking it to dealer.

    Also, what can happen if I swap it with my 1999 r1100 GS's motronic 1.2.

    (continuing thread http://advrider.com/forums/showthread.php?t=753007)
    #1
  2. GAS GUY

    GAS GUY MILE EATER

    Joined:
    Jul 27, 2007
    Oddometer:
    6,300
    Location:
    Garden City, Michigan
    You can't test the motronic, you eliminate all other possibilities.If everything else checks out and you have your power and ground requirements at the motronic then you try a known good motronic.Its the same process with cars.
    I don't know about using different units, or interchangeability.
    You need a good wiring diagram and ohm meter and check continuity on all the involved wiring.
    #2
  3. Dan Cãta

    Dan Cãta Long timer

    Joined:
    Jun 5, 2008
    Oddometer:
    1,993
    Location:
    Cluj, Romania
    If anything would be bad/burnt inside the unit, you can see/smell it :) Really.

    I bet the issue comes from somewhere else, not the motronic. Do you have sparks, Do the injectors squirt? That is the propper test for the motronic :D

    Dan.
    #3
  4. container

    container Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    72
    Location:
    Slovenia
    @dan
    Injectors squirt (hmm ... checked only one thoug), pump goes on when I turn engine by hand, but no spark.
    Checked HES with LED method, she is fine.
    Swapped coil, she has 12V too, she doesn't get signal from motronic though.
    Swapped both fuses (pump & motronic) and relays.

    Havent gone through other sensors though. If I unplug other sensors, what happens, should it have spark?

    I will try open the Motronic connector and see what comes in and out of the pins, check for continuity and voltage. Seems damn lot of work for a ridiculous issue I am sure to find on the end. Something unplugged or not compatible BEH.:puke1
    #4
  5. container

    container Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    72
    Location:
    Slovenia
    #5
  6. Dan Cãta

    Dan Cãta Long timer

    Joined:
    Jun 5, 2008
    Oddometer:
    1,993
    Location:
    Cluj, Romania
    It is not that hard to troubleshoot, a bike such as yours. I will help you though ;)

    First thing. You say it squirts fuel but no spark. Ok... No spark at neither ends? Could it be a faulty spark wire? Check.
    Then take off the tank, see if the coil gets signal. Connect your voltmeter to that connector, the small one that plugs in the coils and crank the engine. Set it to 20V, you should see some signal there, around 8 9 V, varying. That means that your motronic unit is ~ OK :)

    Then check the coil resistance, both primary and secondary windings. The reference resistance values can be found on this board, 13 k ohms the secondary wind. and 0.5 ohms the primary winding. If you do not get these values, your coil is probably bad and you should find another one to see if the bike then starts.

    Also, does your coil not have a small brown wire that connects the outer metal part to the bike frame somewhere? Did you connect that back into place? I don't know what it does, perhaps it is for signal noise or something, but connect that one too. If you have the black plastic type coil, you are good, no wire in there.

    So bottom line is that I bet you did not fry the motronic, just left something disconnected or not connected all the way. I bet you will find the fault and the post here the result, being happy that your bike is alive again.

    What was that you worked again? Give us all the details, the more the better.

    Thanks,
    Dan.
    #6
  7. container

    container Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    72
    Location:
    Slovenia
    Dan, thank you. I am always happy to see here fellows being really helpful.

    About the coil: iI have swapped coil with other, 1100 one, that is supposed to be working, cable too. The coil installed on the bike is strangely caged into steel frame so cant get to the coil itself.
    I also measured voltage at the coil-harness connector and it shows 12V on both when open-lop (ignition off). When closedloop i measure 12v still on one and the other it shows 0V all the time even if I crank engine - did that manually, without starter. So, no signal from motronic, isuppose.

    Had the ground brown wire always screwed to the frame too.

    Will check the other injector too.

    Thanks for the encouradgement, Ive gone thru quite some hirdles now, but, hey, its FUN!:)

    There is also my other post that began with HES testing:
    http://advrider.com/forums/showthread.php?p=17636974&posted=1
    #7
  8. Dan Cãta

    Dan Cãta Long timer

    Joined:
    Jun 5, 2008
    Oddometer:
    1,993
    Location:
    Cluj, Romania
    I think you are measuring the signal that should go to the coil wrong.

    So the coil is just a transformer of voltage, that makes 12V or so impulses to ~ 20kv ones, but of course, in less current flow. So just as you have your inverter to charge a mobile device for example, making 5V out of 110V, the coil works the same way, but increases the voltage, unlike the charger that decreases it.

    So what you should be measuring is the voltage drop against the 2 pins of the connector that drives the coil, while cranking, and not just one pin at a time and ground. Like I said, while not cranking, there should be 0V across that connector, while cranking, the voltage should rise to ~ 9V, fluctuating as the engine cranks.

    So the above is just to test the spark taking place on the bike. I bet that if you measure what I have described about, you get those values, meaning that the motronic is just fine.

    Dan.
    #8
  9. container

    container Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    72
    Location:
    Slovenia
    "lets listen to Dan" I say:

    reconnect multimeter to the coil-harness connector to measure voltage between pins while cranking. I measure this on the swapped 1100 coil. And this time I crank with starter.
    I didn't see the voltage on multimeter as ...whooow SPARKY !!! from the coil's un-plugged wire.

    Ok, so lesson learned: you will NOT GET SPARK if you crank by hand. WTF? I think many people said I should manually crank engine to debug. Hmmmm not for spark, I guess.

    Then I go on and wonder if it was wiring or was it the coil. I reconnect the old coil, unplug 3 spark plug cables from the engine and test only one on the well-grounded bolt. Touch the starter button and ...
    *** click ***
    and tiny smokey from the battery.

    Ups:eek1

    Check all the fuses ... none broke. Shit - shorted sometnhing?
    Recconnect the 1100 coil, ignition, ready, steady SPARK!:clap

    BAD COIL:chace


    Now, the bike is in bits, it is 2:11 morning here in Slovenia, 1 spark plug missing, muffler unattached and parents upstairs sleeping.
    See more in the next episode of "the man and the machine"

    Thanks Dan for troubleshooting and stand-by.

    The dead coil:
    [​IMG]


    Can I use r1100gs coil on 1150 RT?
    (doublespark)
    #9
  10. container

    container Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    72
    Location:
    Slovenia
    The episode continues.

    Installed the other coil to all four sparks and tested the lower two for spark: both sparky.

    Engine still doesn't run.


    Tested TPS: failed.
    It behaves really strangely. It measures cca 0 V across pin 1-4. If I turn TPS with ignition on nothing happens. If I turn engine off, twist throttle till the end, turn engine on, I measure 4V across pin 1-4 on some positions of TPS. At some point of turning, it switches to 4V ... which is also voltage on the other pins. So, not completely dead, but shows some life signs.

    I must mention that this bike was exposed to some serious heating damage (fire in the depot, where it was). TPS doesn't look damaged, though. But so did the coil and the pump ...

    Any ideas besides "swap it"?

    Did OVAD
    I have also opened cylinder covers and found some really strange sediments (white-yellow colored), checked valves for operation and set clearances as in OVAD Oilhead Valve Adjustment for Dummies. Valves were really tightly set.

    Observed engine cranking
    Before that and afterwards I also observed engine cranking: without air filter it blew a big bang back from the airbox once.
    I have removed exhaust pipes and observed a spray of gas spitted out of exhaust holes. I disconnected lambda sensor too. Or whatever that was, but sure wasn't fumes from explosion.

    All four sparkplugs are constantly wet, and I do have spark, supposedly at the right moment. Engine sucks air on one end and spits it out on the other. What else am I missing here?

    It is like a sleeping hypo, cant wake it up, teasing it only makes puffs and grins from that and the other end. :)
    #10
  11. Dan Cãta

    Dan Cãta Long timer

    Joined:
    Jun 5, 2008
    Oddometer:
    1,993
    Location:
    Cluj, Romania
    The bike will not start with a bad TPS. Or it will and will run like crap until ~ 4k rpm. Then, the TPS does not matter anymore. It should show 0.37V at idle and go up, as you twist the throttle until it reaches 4 or 4.5 V - can't remember the exact value, but it's around there. So it should work trough all the way the grip is turned. Other than replacing it, I don't think there is anything else that I can think of, it is not serviceable AFAIK.

    Also, is the throttle cable seated in it's spot on the R?H side? That would make the bike not start too.

    What about the HES? Did you check those? How?

    Dan.
    #11
  12. container

    container Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    72
    Location:
    Slovenia
    Dan, thank you.

    I have tested HES with the method described in the Wisdom, using LEDs attached to the connector and turning engine by hand. LED got lit properly on both top and bottom position.

    I had messed up throttle cables, I have noticed that and put them in place. Both throttle levers move for 1/3 of turn, which is I think normal.

    So, if TPS is toast the engine wouldn't even start? As far as I understand TPS only regulates "richness" of the mixture, and if I get spray of gas from injectors, it should be ok? or not?

    Again, since the culprit of the bike being in my garage was it being burned by fire in a depot, It is easily possible that TPS is toast.

    I have got a r1100 GS. Swapping TPS from it to the "patient" would be a bit of a hassle, I imagine? Even impossible?
    #12
  13. Dan Cãta

    Dan Cãta Long timer

    Joined:
    Jun 5, 2008
    Oddometer:
    1,993
    Location:
    Cluj, Romania
    Change the TPS, then start over. From my understanding, what the TPS does is tell the motronic how wide the throttle plates are opened, and by that info, it adjusts the advance spark angle. For gas richness, you have a lanmbda probe or the potentiometer on the r/H side, towards the back of the bike.

    Dan.
    #13