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lumpy idol,poor running when cold

mikechids Apr 6, 2006

  1. mikechids

    mikechids New Member

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    I have an A3 1.8T (01)(AUM engine) with the following problem.. When I first start the car in the mornings especially when its cold and wet, the car runs very poorly. When idoling the revs don`t stay constant and the needle jumps up and down, sometimes the car will stall (rarely) to get round this I keep the revs up manually by holding down the throttle a little. Once the car warms up then the problem is pretty much unnoticeable except when you come to junctions you can sometimes feel it again.

    Been to the garage about it a number of times, there have been various fault codes, which we dealt with, Temp Sensor - changed, MAF has been changed - no fault code. The fault code I keep getting now is "Random Misfire" which occurs when the idol drops and the car is about to stall.

    Any Ideas?

    The car has a Hyperboost DV and I have changed the Waste Valve in the past aswell. It had new spark plugs about 20K ago.

    Mike
     
  2. RichA3Turbo

    RichA3Turbo ...Watching you! Staff Member Moderator

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    Coilpack??
     
  3. mikechids

    mikechids New Member

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    Should have added!

    Doesn`t happen all the time- intermittant.

    A coil pack wouldn`t be intermittant?
     
  4. MarcA3Turbo

    MarcA3Turbo Member

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    Hey,

    this was dealt with a few weeks ago I think, seems to be a pretty common problem. I have a 2001 A3 Turbo too, and had the same problem. Replaced the MAF and the lambda probe, neither of which made any difference. Just got the car serviced, and my mechanic said the throttle body was pretty filthy, so he gave it a good clean . Seems to have cured the problem completely, no problems since, so fingers crossed its sorted now. Hope this helps.

    Marc
     
  5. AL_B

    AL_B Active Member

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    Could be a coilpack. The ones that don't screw down type. (Queue Rich with a picture again). The coilpacks tended to go more in winter and cold conditions.

    Also search this forum for cold running problems. Had similar, lumpy running when cold on our Golf. I have cleaned the Throttle Body and other bits and its running better. I wouldn't say 100% fixed, but better, 95% say.

    Just occasionally in 2nd gear letting the clutch out, it can be a little jerky as if you've not given it enough throttle.

    Need to keep an eye on it.

    AL
     
  6. RichA3Turbo

    RichA3Turbo ...Watching you! Staff Member Moderator

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    Pic:
    [​IMG]

    Rich
     
  7. AL_B

    AL_B Active Member

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    magic!!
     
  8. imported_hookie

    imported_hookie Guest

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    [ QUOTE ]

    I have an A3 1.8T (01)(AUM engine) with the following problem.. When I first start the car in the mornings especially when its cold and wet, the car runs very poorly. When idoling the revs don`t stay constant and the needle jumps up and down, sometimes the car will stall (rarely) to get round this I keep the revs up manually by holding down the throttle a little. Once the car warms up then the problem is pretty much unnoticeable except when you come to junctions you can sometimes feel it again.

    Been to the garage about it a number of times, there have been various fault codes, which we dealt with, Temp Sensor - changed, MAF has been changed - no fault code. The fault code I keep getting now is "Random Misfire" which occurs when the idol drops and the car is about to stall.

    Any Ideas?

    The car has a Hyperboost DV and I have changed the Waste Valve in the past aswell. It had new spark plugs about 20K ago.

    Mike

    [/ QUOTE ]

    It is due new spark plugs though, worth eliminating the obvious
     
  9. MOSSY

    MOSSY Member

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    i have been having the same problems all winter. Although mine will cut out quite often it will clear once I have given it a few revs
     
  10. typ8l

    typ8l New Member

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    I had a problem recently with "hunting" idle revs, usually when warm. Turned out to be a crack in the short vacuum pipe moulded into the the air inlet hose between MAF and throttle body (1.6 AEH engine).
     
  11. mikechids

    mikechids New Member

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    How does a mechanic check if a coil pack is faulty?

    Is there a standard test? Apart from replacing parts until we find the problem.

    Thanks for the all the input, Have noticed seems to be a common problem but can be caused be many things seemingly.

    Mike
     
  12. AL_B

    AL_B Active Member

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    The actual procedure is checking for mis-fires on the cylinders. If they are detected on a cylinder, you move the first move the plug to another cylinder and check again. If the problem moves to the other cylinder, its the plug. You do the same with the coil packs.

    There is also another test they can do by connecting up an occiloscope.

    AL
     
  13. mikechids

    mikechids New Member

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    The coil pack in the picture... do they just unscrew to get them out?
     
  14. god_thats_quick

    god_thats_quick Numptie of the highest order

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    Not sure if it's the same on that style coilpack, but on my car they are just held in by two hex bolts then lift out.
     
  15. mikechids

    mikechids New Member

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    Mine looks the same as the above picture doesnt` seem to be any bolts.

    Do they just unscrew out?
     
  16. AL_B

    AL_B Active Member

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    Mike,

    They just lift out (if you have no bolts). Be careful though. Don't use a screw driver to leaver them. Just get your fingers underneath, and slowly apply more pressure to lift them out. They just pop out, but can require a decent amount of force. Some people use plastic bicycle tyre levers.

    AL
     

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