sputter/missing after long idle

Discussion in 'Sportster Models' started by 67hat34c, Apr 6, 2010.

  1. 67hat34c

    67hat34c Active Member

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    08 1200c. Had warranty work in last few weeks. Ran too lean so they removed top end to inspect and all was ok. They used Supertuner to retune the bike.

    Now from time to time it misses and sputters when first take off from a redlight. Doesnt do it all the time. First showed up as a stumble and now it actualy pops and sputters. Not aware of any smoke or at least no one has commented on it. Plugs are both clean.

    Is this a tuning problem or could it be a sensor issue. I did check all the easy to get to connectors, all installed properly and all clean inside.
     
  2. Hoople

    Hoople Account Removed

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    How many miles are on bike. When you say "top end" are you saying they removed the heads? When you say they used a Super tuner, do you mean they used a VCI that you purchased in the past? Also check to see if there are any historical codes.
     
  3. hastms

    hastms Member

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    My 05 Hertiage (fuel injected) does the same thing.After I put a pair of V&H longshots on . I have noticed it more after I sit at an idol for a few minutes and it is hot
     
  4. 67hat34c

    67hat34c Active Member

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    Heads were removed and inspected, all ok.

    Purchased HD supertuner for the Retune.

    Bike has 15k miles on it.

    Dropped off bike last night at dealer and they will tune for low speed.
     
    Last edited by a moderator: Apr 15, 2010
  5. Hoople

    Hoople Account Removed

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    I can not imagine it has anything to do with tuning. It sounds more like a vacuum leak after re-installing the heads and throttle body..
     
  6. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    I am inclined to agree with Hoop...your ride is way too young to be having problems and especially if they took the heads off. Any invasive surgery on your bike means a greater possibility of "collateral" damage.

    The dealer should not "just" check what they "tuned" but inspect for something they disturbed, while taking things apart. Classic case of looking for and testing only for what they did. Troubleshoot the symptoms, if intermittent try to recreate, isolate and correct the failure.
     
  7. 67hat34c

    67hat34c Active Member

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    Vacuum leak should show in af numbers when they tune it.
     
  8. Jack Klarich

    Jack Klarich Expert Member

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    Hoople might be on to something here , they have a tool if you will for aligning the intake, I would check for a leak there first
     
  9. Hoople

    Hoople Account Removed

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    Yes & no... It may, but can easily be overlooked. Any cells in the A/F ratio map that are running closed loop will have applied correction by the ECM. The remaining cells that are table driven (WOT) are under low manifold vacuum and won't be affected as much by a small vacuum leak.
     
  10. 67hat34c

    67hat34c Active Member

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    I may ck for vacuum leak myself. Dont trust these guys as they Mess everytyhing up. May use wd40 or use the HD method using propane gas.

    By the way I did give everything a close up visual and could see no issues, also checked all visible electrical connections, pulled, inspected and reinstalled.

    Frankly I cant tell for sure if they did remove top end as they claim, everything looks like it did before. Found one Hot Topper Bolt cover on the forward rocker cover damaged but they had that off before and could have been damaged prior to this. They never clean parts before installing them, there was old reisdue on rocker covers where I cant reach to clean. I know they dont clean parts because when they changed rocker gaskets under warranty, prior service, the bike came back with the oil still on chrome. (Rant: why not clean parts and polish before installing, simple and nice thing to do and sign of quality work or at least a sign that they care)

    Can someone tell me how the Idle Air controll works? What is its status when bike is at higher rpms etc.