2011 990 Adventure abs Idle problem

Discussion in 'Dakar champion (950/990)' started by Erez1984, Nov 11, 2019.

  1. Erez1984

    Erez1984 Adventurer

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    Hello everyone
    My friend has a 2011 990 ABS white that has an idle problem. Bike runs good when cold but after 1-2 minutes starts bogging and shuts down.
    Already replaced : New TPS (calibrated to 0.64v, tried allso 0.60v), new idle step motor, new fuel pump + filters, new spark plugs, coils tested good, lambda sensors tested good, new battery.
    No fault cods on TuneECU and no FI codes on the dash.
    Bike rides excellent, but has this erratic and unstable idle problem (see attached video).



    Does a temp sensor can cause such a problem?
    Any suggestion where to go next before we go into the entire wiring loom and start looking in the dark - will be welcomed.
    Thank you.
    #1
  2. DirtyADV

    DirtyADV Long timer

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    Cleaned up the linkage that the stepper moves?


    Recently had issues with bad/jerky throttle response. Could see little dust making its way into the throttle housings at the axels for secondary valves. Had it apart and cleaned things and a little grease on the felt seals.

    So much better after that. So think the stepper for that had a hard time moving them cause of dust causing issues.

    Maybe similar issue with idle stepper can occur?

    /Johan
    #2
  3. Erez1984

    Erez1984 Adventurer

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    Throttle body is spotless as its sensors got replaced so it got cleaned to the core before that. Everything moves free and the bike runs grate - no throttle issues, just a bad idle were trying to figure out.
    #3
  4. Mleaky

    Mleaky Been here awhile

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    What about the rear TPS?
    #4
  5. Erez1984

    Erez1984 Adventurer

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    Iv shutted down the 2nd throttle valve circuit with TuneECU to test if its coming from there, didnt changed nothing so the 2nd tps is good as far as i can see.
    #5
  6. rider911

    rider911 Shortcut Navigator

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    Interesting problem.
    If you hold the throttle open a little manually, are you saying that it is fine?
    Is it the same when fully hot?
    Was that video taken when fully cold?
    #6
  7. NKL

    NKL Been here awhile

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    Was any work done to it before it started doing this?
    #7
  8. Erez1984

    Erez1984 Adventurer

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    Its cold in the video. After 2 to 3 minutes it doesnt hold idle and shuts down. Tested with another engine temp sensor and another air temp sensor and didnt changed.
    After long web search reading about problems similar to this one my next suspect is the pulse generator wich im going to test tomorrow with the manual specs. alltho it might show its fine and still do that, i hope it will show different values from cold to hot wich will tell me it needs to be replaced.

    It got oil changed and valve inspected at a ktm dealer but thats a long and very expensive story so to make it short they just started changing parts on the costumer expense and didnt solved the issue. eventually the owner took it out of there because the next step they were gonna take is to change the whole throttle bodies for a new set wich is more than 1000$ and said in advance they wont guarantee it will solve the issue.
    Anyway since than weve came along nicely solving other issues it had like the bike ran on one cylinder permanently and was boiling - eventually it was a melted rectifier + and - connector , the rpm didnt ran on the speedo - broken wire that was grounded to the headlight frame and a few more gremlins that got solved and went away, and now eventually the bike runs grate in all ranges of rpm, feels sharp and crisp but iv left with this last and final issue of idle shut downs and the next suspect is the pulse generator.
    #8
  9. rider911

    rider911 Shortcut Navigator

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    Sorry but you only answered one of my questions.
    If you start the motor cold and hold the throttle open a tiny bit (2000rpm) what happens as it warms up?
    When you say "the bike runs grate in all ranges of rpm", whats the lower limit of the rpm before it plays up.

    I dont see how it can be the pulse generator if "the bike runs grate in all ranges of rpm" other than idle.

    Have you studied the stepper motor readings in TuneEcu?
    Without really knowing all the facts, I would disconnect the stepper mechanically (not electrically) and adjust all the slack out of the main throttle cable, opening the butterflies a tiny bit. Obviously this is a temporary solution. Throttle cable adjustment is crucial with the stepper connected but not when its disconnected. I would adjust the throttle cable to achieve 1800rpm at idle when cold and see what happens.
    Even though you have a new stepper, adjusting it is not straight forward or an easy step to understand. Most shops these days struggle to perform basic work, I would have no faith that they have adjusted this correctly.
    Anyway I would like to rule out the stepper/idle function before I moved to the next step.


    Just my opinion :-)
    #9
    mountaincadre and DirtyADV like this.
  10. Erez1984

    Erez1984 Adventurer

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    At 2000 with open throttle it runs ok.

    Already did. took off the stepper motor and set the rpm through the throttle cables, bike was erratic - on one start it went up to 3000, on another it stayed at 1800 but shuted down after a few seconds, on other attempts it went up and down. Calibrated the TPS to make sure, same issues. bike couldnt run without the stepper motor.
    Same test with the step motor connected and TPS calibrated does similar outcomes but above 1800 it runs and wont shut down. going above 1800 it runs smooth, going down to the 1500 range it starts to cut off at shuts down.

    A new info to add to the mix - yesterday the owner rode the bike for 1 hour on highways and in town and the bike ran without stalling in idle from the beginning of the ride until it went back in the garage.
    #10
  11. rider911

    rider911 Shortcut Navigator

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    So at 2000 rpm it runs good, at 1800 it plays up?

    Then you took the stepper off and it plays up even more, i'm confused as to why removing the stepper can make it worse. I dont want to get hung up on the stepper but youre not giving me enough answers to move on.
    "bike couldnt run without the stepper motor" ??? TuneEcu stepper readings??? How do you know the stepper is adjusted correctly???

    Ive said this many times on here, buy a secondhand throttle-body assembly off eBay and eliminate 20 possibilities.

    Inside the throttle-body wiring loom there is a crimped earth joiner that has been known to oxidise and cause erratic idling.




    Well thats really bad news, its going to make ongoing diagnosis extremely difficult.

    Good luck
    #11
  12. Erez1984

    Erez1984 Adventurer

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    Didnt knew that the TB wiring loom had earth joiners so before anything else i went ahed and thested all the wires from the main connector of the TB to all the sensors including double check every earth joiner, all are good (played with the loom on each wire test)

    [​IMG]

    Next thing i did is to test the pulse generator after building a peak voltage adapter for the test and it came out good, everything is in specs (ohms + voltage)

    Its not very clear, when set to 2000 rpm through the throttle cables it runs for 2 minuts and than starts to cut off. Iv added 2 videos wich were taken on the same run with a few seconds pause between them. Allso pointed the stepper motor when it starts to cut off, looks like the stepper isnt taking part of this issue:




    When i took the stepper off i held the throttles by adjusting the cables and started it. The bike was erratic - jumped up to 3000 when i started it, went down to 2000 and backfired, than shutted down. Next thing i did is to shut down the 2nd throttles circuit (no stepper on the TB) - Bike did the same problems.
    Next step i took is to shut down the stepper motor circuit (no stepper on the TB)- bike didnt start. Put back on the stepper motor circuit - it starts but has the same erratic issues.
    Next iv adjusted and verified the TPS voltage again and had few more tries - similar results, very erratic and unstable - jumping up and down, sometimes shuts down faster than others.
    I know it does not seems very logic and one of the first things i did is to try run it without the stepper motor but these were the results.

    I dont. I measured the length of threads where the lock nut sits on the old stepper and did the same when putting back the new one.
    If theres a way i can verify through TuneECU the stepper motor adjustments are correct (any base line measures/ data?) id be happy to know them.

    Yeah i knew i hit the Jackpot when he told me this.

    Thanks for the replies.
    #12
  13. pulpo2011

    pulpo2011 Adventurer

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    did you test map sensor volts and values, TB Sync and adjust throttle cable with tune ecu?
    #13
  14. Erez1984

    Erez1984 Adventurer

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    Yes both MAP sensors works fine and have allmost identical voltage on TuneECU.
    Throttles were syncd earlier on.
    Cables adjusted properly every time.
    #14
  15. pulpo2011

    pulpo2011 Adventurer

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    Suggest another things you can test:
    1.- Intake manifold air leak.
    2.- Fuel pump pressure test.
    3.- Dirty Inyectors
    Good Luck
    #15
  16. LopezXC

    LopezXC Been here awhile

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    Check for a pore in throttles. When cold, it's closed, but when warm, pore dilated and throttle get air inside. Could you check with other throttles?
    #16
  17. Erez1984

    Erez1984 Adventurer

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    So weve managed to borrow a good complete low mileage Throttle bodies assembly for the test and... unfortunately bike still has the same issues - Runs ok when cold for 1-2 minutes and than starts to bogg, doesnt want to hold a steady idle, cutting off and so on. by that we now know for sure its not coming from the throttle bodies or any of the parts that sits on them.
    Seems like the ECU is getting wrong inputs after the bike warms up, what about the coolant temp sensor? is it possible that if its faulty it will make the ECU keep the mixture rich while the rpm drops to the 1500 area?

    In the video below you can see how it works with the borrowed TB assembly
    (the FI light is the air temp sensor disconnected)
    #17
  18. rider911

    rider911 Shortcut Navigator

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    Well at least you have made some progress in eliminating lots of possibilities.

    Have you got access to a scope meter?
    I think I would back probe the coil plugs and see if I could determine if a signal was dropping out on one or both cyl

    I dont think it will be the temp sensor but obviously you could simply unplug it to see if anything changes.

    Since you must have another donor bike, you may as well try its ecu. Its very rare for the ecu to die never mind do something as random as this but it will cost nothing and take no time. I have seen minor corrosion on ecu pins or loom plug that have caused random running issues, maybe its worth studying all the plugs. Electronics run on such fine voltages it doesnt take much corrosion the alter the signal.
    #18
  19. Erez1984

    Erez1984 Adventurer

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    I dont have a scope access but if it helps one of the first things i did was to hook up led light on each coil plug and ran the bike, couldnt see a noticable drop in the strobes other than equivalent to the rpm's drops down, but i guess it cant be determined by eye sight.

    I did and it changed nothing, but what if the sensor is faulty on warmer temps? I mean what if it doesnt tell the computer the coolant temp went up - wich in this case ill get the same result as running the bike with the connector unplugged from the sensor?

    Not exactly a donor but a wrecked Superduke 990 that was bought for its engine and the guy was willing to lend the TB's he had. As for the ECU he allready sold it but ill try to find a running 990 Adv to replace ECU for the test.
    #19
  20. LopezXC

    LopezXC Been here awhile

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    Strange... I'll pass your video to a mechanic... Let's see if he can help...
    #20