Ridemalibu Motorcycle Rentals & Tours – Los Angeles CA
  1. Ciao Guest - You’ve landed at the ultimate Guzzi site. In SoCal? See the SERVICE tab above for the best in service, tires, tuning and installation of our products or custom work. NEW FORUM REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER - Use the CONTACT above if we can be of help. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - Most questions you may have are already answered on the Forum with FACTS, NOT OPINIONS. PLEASE DON'T BE A DRIVE-BY POSTER: As a common courtesy, check back if you are posting elsewhere on the web. Note there's decades of Guzzi hands-on experienced help on this site, all whom give endless amounts of their time for free; BE COURTEOUS AND RESPECTFUL! Also be sure to click on the STORE link also above for our 600+ product inventory, including many of our 100% Made-in-house-USA GTM products and engine kits. We appreciate the consideration, understanding and your business... past and future. And if you haven't seen our MotoCycle (not) art, click on the BUILDS tab above to see our work at our sister business; GT MotoCycles® -- WE ARE ONLINE ONLY - NO PHONE CALLS MADE OR RECEIVED.
  2. There is ZERO tolerance on personal attacks and ANY HYPERLINKS to a PRODUCT or other competing website(s), this includes personal pages, social media or other Forums. We work very hard to keep info relevant here. First offense is a note, second is a warning, third time will get you banned from the site. Sorry to have to do this, but we don't have the time to chase repeat (and ignorant) offenders. This is NOT a social media platform; It's an ad-free, privately funded website, in small help with user donations. Be sure to see our online STORE link above; GTM product purchases help support the site, or you can upgrade your Forum profile or DONATE via the link above.

Fast Idle when HOT Stumped

Discussion in 'BNS12 Chat & Tech' started by SpeedwayRN, Oct 23, 2014.

  1. SpeedwayRN

    SpeedwayRN Tuned and Synch'ed GT Contributor

    Joined:
    Aug 4, 2011
    Messages:
    46
    Likes Received:
    3
    Location:
    Justin, Tx USA
    Still having problem with fast idle when the engine gets nice and hot up to operating temp.
    Idles at 1800.
    No error codes.
    I have blocked off the stepper motor and all vacuum connections.
    Checked all the boots and clamps and airbox for leaks.
    Nothing seems abnormal. Even spraying WD40 around the throttle bodies and connections doesn't reveal any sort of air leak.
    Removed and cleaned injectors.
    TB stay balanced
    Valves checked
    I am stumped.
    Any ideas?
     
  2. john zibell

    john zibell Moderator Staff Member GT di Razza Pura

    Joined:
    Oct 28, 2008
    Messages:
    8,416
    Likes Received:
    1,079
    Location:
    Huntsville, AL
    Have you read the temperature sensors in real time? Something may be off getting the mix too rich or lean resulting in a fast idle. Also when you cleaned the injectors, did you clean the TB butterflies? Is more than one idle bypass screw open?
     
  3. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,896
    Likes Received:
    286
    Location:
    B'more, Md
    If you blocked off the stepper motor and it still idles high there is probably air getting in from somewhere. Adding more fuel (too rich) will not raise the idle, although too lean can cause a hanging idle but it usually will not stay up there.
    Look for vacuum leaks. Has anybody messed with the "sacred screw"? Perhaps the throttle plates are just too far open at idle. Has it always done this? With the stepper blocked off there should not be enough air to idle that high.
     
  4. SpeedwayRN

    SpeedwayRN Tuned and Synch'ed GT Contributor

    Joined:
    Aug 4, 2011
    Messages:
    46
    Likes Received:
    3
    Location:
    Justin, Tx USA
    I got the bike with a few hundred miles. It seemed to develop after a few thousand miles. So the TB were set at factory specs. I have been chasing this for 12k miles or so. Only one bypass screw is now open. The throttle bodies are spotless. The yellow paint on the sacred screw appears to be in tact. When the motor is cold it idles at 1100 rpm. After riding it and getting it up to temp you come to a stop light and it won't idle lower than 1800. Even spraying with WD40 around all the rubber boots and throttle bodies no changes in RMP.
     
  5. john zibell

    john zibell Moderator Staff Member GT di Razza Pura

    Joined:
    Oct 28, 2008
    Messages:
    8,416
    Likes Received:
    1,079
    Location:
    Huntsville, AL
    Kind of grasping at straws here, but have you checked the manifold connections at the head? There are some o-rings there that could be failing or the screws may have come loose.
     
  6. SpeedwayRN

    SpeedwayRN Tuned and Synch'ed GT Contributor

    Joined:
    Aug 4, 2011
    Messages:
    46
    Likes Received:
    3
    Location:
    Justin, Tx USA
    I have not but I have sprayed WD 40 all over the engine looking for leaks to no avail. I will check that though to be sure.
     
  7. GTM®

    GTM® Administrator Staff Member GT di Razza Pura

    Joined:
    Jul 1, 2009
    Messages:
    12,308
    Likes Received:
    4,505
    Location:
    Malibu
    Be sure to check the lines from the output side of the stepper motor to the throttle bodies as well.
     
  8. SpeedwayRN

    SpeedwayRN Tuned and Synch'ed GT Contributor

    Joined:
    Aug 4, 2011
    Messages:
    46
    Likes Received:
    3
    Location:
    Justin, Tx USA
    Thanks Todd
    I have completely blocked all the stepper motor passages. The one that goes to the air box and the ones going to the throttle bodies. Sealed with thick vaccium caps and zip tied in place. The stepper motor is still bolted in place but neither the in or out is connected to the airbox or throttle bodies.
     
  9. JJC1957

    JJC1957 Tuned and Synch'ed

    Joined:
    Jul 10, 2015
    Messages:
    35
    Likes Received:
    3
    Location:
    Rehoboth, MA
    Did anyone ever find out what was causing the high idle? My 2008 Norge does the same thing and the dealer that I go to has no idea why.
     
  10. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,896
    Likes Received:
    286
    Location:
    B'more, Md
    Did you try any of the steps mentioned in this thread?
    If so, what did you find?
     
  11. JJC1957

    JJC1957 Tuned and Synch'ed

    Joined:
    Jul 10, 2015
    Messages:
    35
    Likes Received:
    3
    Location:
    Rehoboth, MA
    No I just purchased the bike and took it to the dealer who tried to fix it. They set the throttle bodies and the TPS new injectors flashed the ECU. Still runs the same. I think I will look at the stepper motor next.
     
  12. SpeedwayRN

    SpeedwayRN Tuned and Synch'ed GT Contributor

    Joined:
    Aug 4, 2011
    Messages:
    46
    Likes Received:
    3
    Location:
    Justin, Tx USA
    I tried everything except cleaning and or replacing the O2 sensor. Even disconnected the stepper motor.
    I just sold the bike to buy a Motus MST.
     
  13. JJC1957

    JJC1957 Tuned and Synch'ed

    Joined:
    Jul 10, 2015
    Messages:
    35
    Likes Received:
    3
    Location:
    Rehoboth, MA
    Great looks like I am a lone on this one. The dealer doesn't know but they could start replacing parts until he gets it. Very expensive way to do things. The funny thing is it only idles at 1,800 RPM when you stop in gear with the clutch pulled in. If I put it in neutral and let the clutch out she goes right down to 1,100 RPM??????
     
  14. SpeedwayRN

    SpeedwayRN Tuned and Synch'ed GT Contributor

    Joined:
    Aug 4, 2011
    Messages:
    46
    Likes Received:
    3
    Location:
    Justin, Tx USA
    Try cleaning the O2 sensor. That's next to free.
    I have seen used O2 sensors for $35 on eBay.
    Mine idles speed normal until it warmed up then idled at 1800-2000.
     
  15. JJC1957

    JJC1957 Tuned and Synch'ed

    Joined:
    Jul 10, 2015
    Messages:
    35
    Likes Received:
    3
    Location:
    Rehoboth, MA
    My bike does the same thing
     
  16. StormShearon

    StormShearon Cruisin' Guzzisti

    Joined:
    Oct 28, 2008
    Messages:
    195
    Likes Received:
    5
    Location:
    Sammamish, WA
    Actually, it may be a problem with the clutch switch. I ran into this on my '07 Norge. For some reason they tie the switch into the idle - I think it is done so as you release the clutch while in gear there is an automatic increase in RPM. But if the switch is bad (what happened with mine) the ECU seems to think it needs to up the idle to 1800. Something to check out anyway.
     
  17. JJC1957

    JJC1957 Tuned and Synch'ed

    Joined:
    Jul 10, 2015
    Messages:
    35
    Likes Received:
    3
    Location:
    Rehoboth, MA
    Where do I find the clutch switch?
     
  18. GTM®

    GTM® Administrator Staff Member GT di Razza Pura

    Joined:
    Jul 1, 2009
    Messages:
    12,308
    Likes Received:
    4,505
    Location:
    Malibu
    It has nothing to do with the clutch switch. The difference in RPM with the clutch in/out has to do the with friction from the clutch pushrod/flywheel. Your high idle issue has everything to do with the Stepper Motor. Well documented here... if you don't want to read above, do a search for Stepper Motor. You'll find plenty of info. I might just combine this thread.
     
  19. JJC1957

    JJC1957 Tuned and Synch'ed

    Joined:
    Jul 10, 2015
    Messages:
    35
    Likes Received:
    3
    Location:
    Rehoboth, MA
    Ok I read it again and if someone totally blocked the stepper motor don't you think it could be something else? What do you mean if I don't want to read what is above? This type of menu is for people to share with others the problems they have had and the fix to that problem. When I do find the problem and I will I will share the fix. You may be correct that it is the stepper motor time will tell.
     
  20. GTM®

    GTM® Administrator Staff Member GT di Razza Pura

    Joined:
    Jul 1, 2009
    Messages:
    12,308
    Likes Received:
    4,505
    Location:
    Malibu
    Sorry, I didn't read clearly. If the Stepper motor is in fact completely blocked off, and if everything is to spec and the "sacred screw" that controls idle is still factory set, you'll still need to connect to the bike with some type of diagnostics tool to see if anything else is flagged. If al checks out there, then you may have an air leak.
    Yes this Forum is to share problems, but the same subjects come up over the years, and it just takes a search and some reading to uncover 90% of the issues. There's more then 10 pages on this subject, is this section alone.

    I'll be watching for what you find.
     

Share This Page