990 high/erratic idle - throttle cable or...?

Discussion in 'KTM 950/990' started by DanoPDX, Jun 28, 2016.

  1. DanoPDX

    DanoPDX Been here awhile

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    My '08 990A developed the high/erratic idle problem during a road trip. None of the easier fixes helped, and two shops found no engine faults or other clues when hooking the bike up to diagnostics. I limped home by frequently restarting the bike (including while rolling in traffic), and am trying to sort things out.

    I have a couple of questions about the role a funky throttle cable might be playing. I've also included notes on where I stand with causes/fixes from other threads. Any words of wisdom appreciated. I have moderate mechanical aptitude, but don't have a TuneECU and haven't wrapped my head around the finer points of the bike's electronics. The engine is stock, except for a tamer throttle cam.

    Thanks!

    THROTTLE CABLE QUESTIONS:
    -- I can't tell from my shop manual, etc., if it's the "return" cable or not, but one of my cables has a crack in the plastic sheath (where the cable passes the steering tube) and a little corrosion showing through. (It's the cable that connects to the "close" side of the throttle tube (closer to the rider.)
    -- Am I correct in seeing that more recent 990 manuals show how to replace the throttle cables? Mine doesn't cover it. If anyone wants to send me the relevant pages, I'd be grateful.
    -- I was thinking of doing the replacement at home, and then have a KTM shop do the fine adjustment. But if they're deep enough into the airbox to adjust the cables at the throttle body, check the TPS, etc., maybe I'm not really saving much cash?

    MORE ON THE SYMPTOMS:
    -- Bike will run fine for awhile (anywhere from a few hours to a few minutes), then start misbehaving in one or more ways: Not much engine braking when I close the throttle. Idles at 1.5k, 2k, 3k, and a few times even 4k rpm when throttle closed and clutch pulled or in neutral (it normally idles closer to 1.3k). A few times, the idle jumped really high on its own (3k or more), with throttle closed and bike in neutral.
    -- Turning off the key and restarting the bike fixes it - for a while.
    -- The problem started during a road trip, and got progressively worse over several days. Limping home, I eventually was restarting the bike very frequently, and practically couldn't ride through towns.
    -- The bike seemed to get a mid-RPM surge in mid-gears (3rd and 4th) when the idle was starting to get out of whack again. Which points to a TPS issue per some other threads.
    -- Also noticed that when it was idling high, the RPMs would drop some when I put the bike it gear. (I only tried putting it in gear this way a couple of times.)
    -- Also noticed that during key-on initialization, when the tach is returning to 0, it drops faster when it passes 2k (but maybe that's normal and I never noticed).
    -- Mileage poor by trip's end, no surprise.

    POSSIBLE CAUSES/FIXES FROM OTHER THREADS [AND MY STATUS]:
    -- 15 minute reset. [Tried this several times, didn't help.]
    -- Bad batter connections. [Mine seem fine. Battery is also newish.]
    -- Fuel filter/pump issues. [Not really checked, but I ruled this out as it runs very differently than when I had a clogged filter a few years ago, and it runs fine for periods of time, etc.]
    -- Air temp sensor at top of airbox. [Appears properly connected, not otherwise checked.]
    -- Throttle body vacuum/air leak. [Not really checked, though there's nothing obviously loose in the airbox. Though note the valves were recently adjusted....]
    -- Bad regulator. [Not checked]
    -- Reset the idle controller. [Not checked]
    -- Throttle position sensor (check, adjust, or replace). [Not checked, except that nothing showed up on diagnostics. Note I was getting the surging that some threads like to TPS issues.]
    -- O2 sensor. [Not checked, aside from nothing showing up on diagnostics.]
    -- Bad stepper motor. [Not checked]

    One of the shops did find and replace a bad exhaust gasket, thinking it would help. It didn't help, but the gasket was definitely bad - breaking apart and sliding out. Too bad I didn't catch it at home. They also reconnected the air tube that runs from the charcoal canister to something in front of the air snorkel (an air valve, per my parts diagram), which as far as I can tell had no effect.
    #1
  2. catalina38

    catalina38 Long timer

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    MAP sensor ports in intake may be dirty or partially clogged
    #2
  3. Zuber

    Zuber Zoob Supporter

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    Check the TPS sensor voltage. It needs to be reset at about 10k miles on all bikes. It will cause a random high idle.
    #3
    Deviant666 and thebarber like this.
  4. dakotav8

    dakotav8 Been here awhile

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    Following! My 12r started doing the same thing recently at around 10k miles. I noticed my tps sensor's volatge values change every time I cycle the key, And It gets way worse in hot ( 90 degree ) weather. I'm going to try a new tps sensor.
    #4
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  5. DanoPDX

    DanoPDX Been here awhile

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    Thanks everyone!
    #5
  6. catalina38

    catalina38 Long timer

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    FWIW I did have a few high idle episodes back when the bike had about 10k miles. I did a reset with TuneECU while installing the 11/12 "R" map on my 2010 990R and it hasn't happened since.
    #6
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  7. pulpo2011

    pulpo2011 Adventurer

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    take off air filter cover and filter. Look and touch with your fingers trootle and return cable. they should have a little slack, with tuneecu and the ignition on adjust trottle to cero, turn ingnition off. Adjust cables again if necesary.
    With Tuneecu Adjust tps to 0,59 warm engine, reset adaptation option and 15 mts reset.
    Sorry for my bad english.
    Ricardo
    #7
  8. AJ990R

    AJ990R motorcycle guy

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    +1
    same issue plagued my bike....resetting the adaptations kinda helped....adjusting the TPS slightly seemed to finally fix it(it was in "spec", but adjusted slightly, good ever since):hmmmmm

    thought someone started a thread on this??
    Good Luck!
    #8
  9. dakotav8

    dakotav8 Been here awhile

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    Is there a reset option for tuneecm andriod? I think a reset mite help in my case.
    #9
  10. dakotav8

    dakotav8 Been here awhile

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    I found the reset option in tune ecu android. Reset the tps, Did a master reset and the the 15min idle. Totally fix my problem. I recommend the android version to anyone who has an android device. Best 12 bux's I've ever spent.
    #10
  11. Tabbi

    Tabbi Adventurer

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    WOW never heard of this to be done nor my KTM dealer here in Germany. But I will store in my longterm memory.
    I had exactly the same symptoms and it cost me a lot of bugs including ne valves.

    Normaly (after reading tons of threads all over the forums) you have a bad stepper motor (I believe you know you can buy it via TRIUMPH).
    And avoid buying a new throttle body!

    Also possible with the windows version on a laptop? (I see I have to buy the cable should be a worth investment?) And where you find this options?


    I wish everyone can solve his problem without 1k € or more.
    #11
  12. Errhead

    Errhead Low Miles!

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    Dano, I've got the cable in SE Portland which you are welcome to borrow if you need it. I have never played with TuneECU however since my '08 is running great.
    #12
  13. howl

    howl 990 Adventure

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    I have had the same problem ,can you please tell me how do you reset the TPS using TuneECU?
    #13
  14. Tabbi

    Tabbi Adventurer

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    Yep.,
    Would be nice if someone could write the needed information about the TPS settings, how adjust the throttle wire and the other things to do.

    Make it anywhere sticky?

    Thanks boys!
    #14
  15. DanoPDX

    DanoPDX Been here awhile

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    Thanks everyone. I've had to put this project on hold while slammed with work and house projects, but hopefully getting back to it soon as I kick this jet-lag and cold.

    Errhead, thanks very much for the offer. Will let you know.

    DH
    #15
  16. rattis

    rattis Long timer

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    My -07 had a problem witht the idle, mostly high and it turned out to be the stepper motor.
    At that time i did not know about the Triumph option and had to fork out a substantila amount of money for a new injection system.
    But being on a trip and very far away from home I had zero options, and using my Visa did not hurt as bad as handing over a wad of dollars.
    Still All American KTM in Ramona or whatever they're called helped me out with a good price, very nice people by the way.
    #16
  17. DanoPDX

    DanoPDX Been here awhile

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    So I'm finally back... With all the other crap falling in my lap this summer, I punted and had my local dealer/wrench install the new throttle cable, check the TPS sensor, etc. Cables went in fine, he re-synched the throttle bodies (which were off), found and removed something clogging the input tube to the air pressure sensor (I'm assuming the forward one, not either of the ones on the cylinders), and said the TPS and other sensors checked out OK. The sensor tube clog seemed the obvious culprit, and the bike ran fine.... Until I took it for a longer shake down ride, and the idle problem came back, progressively worse over the course of the ride, with the thing eventually even accelerating on its own, with the throttle closed.

    So I'm back to square one, and would be grateful for any further advice. Based on your input and other posts, the TPS and air pressure sensor(s) still seem the likely culprits.

    Q1: What's the trick to cleaning the MAP sensors? Didn't find anything with a search of OC or more generally. Remove and flush them with some no-residue solvent, like stove fuel? Something else?

    The dealer's wrench is also thinking maybe the fuel pump.

    Q2: Would a faulty fuel pump match my crazy idle/throttle symptoms (see my OP)? The symptoms are very different than what I experienced a few years ago with a clogged fuel filter, so I'm assuming it's not that.

    Thanks for bearing with!

    DH

    Thanks everyone!
    #17
  18. Tabbi

    Tabbi Adventurer

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    If you have the possibilty changing the complete throttle body? Only for trying. Do it and all problems are Gone.
    Then you know ( in 99% its the stepper motor) thats something wrong there. Because you testet the TPS it WILL be the stepper motor.
    Buy it change it and you have a well running beast.

    The stepper motor reset every time you turn the engine off. Thats why its hard to see the problem there.

    Its one of the inexpensive solution.



    Good luck
    #18
  19. DanoPDX

    DanoPDX Been here awhile

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    Thanks Tappi,

    I can't speak for whether the dealer correctly checked the TPS... I've had decent luck with this mechanic, but had a hard time getting details on this point from him.

    Not sure where I'd find another throttle body without dismantling someone else' bike or buying a new one, which runs for about 1,000 USD.

    Better to just buy a new stepper motor from Triumph? If another thread I found is correct, it costs about 200 USD, and is PN T1241182 for the 1050 Speed Triple. http://advrider.com/index.php?threa...control-stepper-motor-operation.597191/page-2

    While we're at it, I found a thread stating the TPS PN is 61041077000, at least for the 990 SD (I have the 990 A) and was found at KTM Twins. KTM Twins' site lists it as out of stock, but at least it exists... Price is about 100 USD. I could replace both it and the stepper for far less than a new throttle body.

    dh
    #19
  20. NKL

    NKL Been here awhile

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    Throttle cables have not been adjusted correctly, you have to use the TuneECU adjust throttle cable setting or do it with a fully hot engine
    #20