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Help - overfuelling mystery

Discussion in 'A3/S3 Forum (8L Chassis)' started by salsheikh, Nov 12, 2010.

  1. salsheikh
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    salsheikh New Member

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    [Nov 12, 2010]
    My AUQ engine has recently started to overfuel.

    So far the lambda sensor/MAF/Injectors/FPR have all been changed but still overfuels.

    Did a smoke test and had a boost leak from the intercooler MAP sensor but this is now fixed.

    The car is on a standard oem map but the mechanic could not adjust the fuelling to stop it from overfuelling.

    Been told that the head will have to come off for further investigation.


    Any ideas what it could be? no fault codes showing either
    #1
  2. s3dave
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    s3dave TFSI Hybrid Supporter

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    [Nov 12, 2010]
    Have you got any logs?
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  3. salsheikh
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    salsheikh New Member

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    [Nov 12, 2010]
    sadly no mate. car is with nick at R-tech and he is trying to sort it.
    #3
  4. evilscotsman
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    evilscotsman Space Cowboy

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    [Nov 12, 2010]
    map sensor reporting too high throughout the rev range?
    #4
  5. salsheikh
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    salsheikh New Member

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    [Nov 12, 2010]
    wouldnt this show up on vagcom?
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  6. Mpathe
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    Mpathe 1st gear

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    [Nov 12, 2010]
    what makes you think it's overfueling?
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  7. bengal
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    bengal Member

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    [Nov 12, 2010]
    Im surprised the temp sensor hasnt been mentioned as when they go bad they can cause the car to run on cold start which it will then overfuel. They dont always show up on vag com or on the temp needle as a problem.
    #7
  8. salsheikh
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    salsheikh New Member

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    [Nov 12, 2010]
    will get this looked at, thanks.
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  9. Broken Byzan
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    Broken Byzan Photographic Moderator Staff Member Moderator VCDS Map User

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    [Nov 12, 2010]
    TBH Nick is pretty switched on, i cannot imagine he has left simple things to chance. What gives the impression it's overfueling?
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  10. salsheikh
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    salsheikh New Member

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    [Nov 12, 2010]
    this is what Nick said is the problem.
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  11. salsheikh
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    salsheikh New Member

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    [Nov 13, 2010]
    update,

    compression test - ok
    turbo oil seal - not looking good as oil found in pipes so turbo is gonna be sent to be checked and repaired.
    not loosing any coolant at all or much oil before this happened.
    coolant sensor changed.

    thanks for all the replies guys. will update once i know more.
    #11
  12. GeeJay89
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    GeeJay89 New Member

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    [Nov 14, 2010]
    Could be an obvious question, but what's the temperature gauge at, 90? Anything else and it could be the stat, which in turn would cause it to overfuel. Got an extra 60 miles for £25 of petrol once I changed it.
    #12
  13. salsheikh
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    salsheikh New Member

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    [Nov 14, 2010]
    temp always sat at 90 on my car. i was getting about 250-300 to the tank full

    Nick said the turbo shaft has got lots of play in it too and gasket is fooked.

    will get this repaired by turbo dynamics i think he said.
    Last edited: Nov 14, 2010
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  14. Broken Byzan
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    Broken Byzan Photographic Moderator Staff Member Moderator VCDS Map User

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    [Nov 14, 2010]
    -What i do not understand is , a faulty turbo won't cause overfueling as the fueling is airflow driven. So no boost means less air, and therefore less fuel
    #14
  15. salsheikh
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    salsheikh New Member

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    [Nov 14, 2010]
    i think the overfuelling was due to the boost leak from the MAP sensor where the leak was found.

    white smoke coming from the turbo seaping oil
    #15
  16. Prawn
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    Prawn My other car is a MINI!!!!

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    [Nov 14, 2010]
    That's all I ever get anyway! haha
    #16
  17. salsheikh
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    salsheikh New Member

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    [Nov 15, 2010]
    i was getting about 300-320 before...when i first got the car.
    #17

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