Idle too high

Discussion in 'GS Boxers' started by Spaggy, Nov 12, 2012.

  1. Spaggy

    Spaggy Long timer

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    2004 1150 twin spark.
    Every time I tuned my throttle bodies previously, the BBS were about 3/4 of a turn out from bottom and fairly close to each other. The last time I went for a ride, the idle was at 1400 when I was done. It's done this before, but only up to about 1250 after a good hard highway run and always came back to normal afterward. Now it's hanging around that 1400 mark and i can't get it down. I turn the BBS almost closed to get it down a bit and now they are a full turn plus apart from each other when balanced. I pulled them right out and they were fairly black, cleaned them and sprayed throttle body cleaner in the hole and no change. I thought maybe a stick coil was goofing off, so I uncapped my secondary plugs and it made no difference at idle.
    What next?
    Any suggestions are appreciated.
    #1
  2. street_moto

    street_moto Adventurer

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    Hard to say without seeing the bike, but sounds like a possible air leak or one of the TB's hanging up on the cable.
    You can check for air leak by spraying WD40 or something similar around TB's and manifold joints with the bike ticking over. A change in idle will indicate where leak is.
    Let us know how you get on!
    #2
  3. Steptoe

    Steptoe steptoe

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    Sounds like your TPS could be out of adjustment.
    #3
  4. Spaggy

    Spaggy Long timer

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    Does the TPS go out on its own? I didn't mess with it.
    #4
  5. pcwirepro

    pcwirepro Aspiring Adventurer

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    Do you have some slack on the cables? Is the fast idle cable not seated in the bowden box?
    #5
  6. (I^2)R/746

    (I^2)R/746 Rider

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    Miles on the bike? Just went through my TB's and found the seals shot and more importantly the air screw passages all gunked up. So I did it by the numbers:
    -Adjust valves
    -New plugs
    -Rebuild and thoroughly clean TB's
    -TPS adjust
    -Throttle cable adjust
    -Carb balance

    Still need to do the rocker arm end gap that's for the next round. Anyways I got the bike with 89k now has 92k and runs way, way better than when I got it. Think the full TB rebuild kits from Bing for both sides was $237 or so. In retrospect I wouldn't do that just get the parts I needed as the shafts and bushings were OK. Took about 4 hours start to finish.
    #6
  7. Steptoe

    Steptoe steptoe

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    Very simple - Why not check it. Then it's another thing you/we can cross off the list as being the potential source of your problem. :wink:
    #7
  8. Spaggy

    Spaggy Long timer

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    I did put some slack in the cables and the fast idle lever pulls up a bit before it makes the idle go up, so I don't think it cables hanging up
    #8
  9. Spaggy

    Spaggy Long timer

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    37000miles, valves and end play adjusted, TBs were balanced but now they're out from me "fixing" it.
    #9
  10. Spaggy

    Spaggy Long timer

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    I'll check that next. Just found the procedure in advwisdom. Thanks
    #10
  11. Spaggy

    Spaggy Long timer

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    Ok, TPS at 0.37 so I left it alone.
    While looking at things, I noticed the o-rings from the intake tube to the TB were not seated properly, ring sticking out at the bottom.
    [​IMG]
    Both sides were like this. When I pulled the tube back, both o-rings were biffed.
    [​IMG]
    I'm assuming that this is at least part of my problem and probably all of it, so I'll have to get new o-rings and put it back together. Meanwhile, I'm going to clean the TBs
    #11
  12. pcwirepro

    pcwirepro Aspiring Adventurer

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    I hate those flimsy little buggers. I tried like hell to re-use a pair this summer but to no avail.
    #12
  13. Spaggy

    Spaggy Long timer

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    Still too high at 1400. I put new o-rings in and made sure they seated properly. Cleaned both TBs and BBSs along with the hole they came out of. Made sure the cables were backed off so the butterflies close at the stop. Checked the TPS and it read 0.37v. Today, I'm going to recheck my valve adjustment and rocker end play just incase I screwed something up there.
    #13
  14. Spaggy

    Spaggy Long timer

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    Valves and rocker end play are good. Even changed out my stick coils for the spares I have and still the same. Could it be an oxygen sensor? Still runs great except for the high idle, maybe I should just leave it alone.
    #14
  15. Spaggy

    Spaggy Long timer

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    Anybody have any ideas?
    #15
  16. (I^2)R/746

    (I^2)R/746 Rider

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    There is an adjustment procedure that indicates "some" GS's idle high and to adjust the TPS voltage accordingly in increments. Have you tried this? Mine idles a little high as well but I've left it alone. I think if it doesn't bother you, and the BBS are close, and it FEELS right then why screw with it. Just ride.
    #16
  17. Spaggy

    Spaggy Long timer

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    The TPS voltage is right where it should be. The higher idle doesn't bother me as much as the thought that I don't know what is causing it.
    Right now I can't ride much because of snow but I'm leaning toward just leaving it until spring. Who knows, maybe I just got some winter fuel.
    #17
  18. ragtoplvr

    ragtoplvr Long timer

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    Check for a small stone or something in the cable pulley or a cable housing not seated. You may have an air leak. I suspect the rubber adapter that holds the TB. I use carb cleaner to check, spray around where the tb joins and where the adapter meets the head.

    Good luck.

    Rod
    #18
  19. Spaggy

    Spaggy Long timer

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    As for the small stone, I've had the TBs off for cleaning and made sure there was slack in the cables when I put them back on. Tried spraying carb cleaner around the rubber adapters and got no indication of a leak.
    #19
  20. roger 04 rt

    roger 04 rt Long timer

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    You've got slack in the cables and the throttle plates are coming to rest against the stop screws? Standard Coding Plug?

    To idle faster it needs more air and a bit more fuel. If you know anyone with a GS-911, you can use it to see what is happening. E.g. Is the TPS showing open more than 0.32 degrees.

    One thing you can do to test the O2 is to full fuse 5 for a minute, reinstall it, turn the key on but dont hit the starter, rotate the throttle to Wot and idle twice (fast idle lever down), turn the key off. Now start the engine and see what you've got.
    #20