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Faulty AFM - Signs ?

Discussion in 'A3/S3 Forum (8L Chassis)' started by Jasdent, Feb 9, 2007.

  1. Jasdent

    Jasdent Mahonee

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    Alright ? seem to have a lot of questions needin answered ! :)

    S3 is supposed to be 265hp but doesn't feel like it. I understand that the AFM are supposed to be a common fault on these cars, what's the best way to confirm a fault in the AFM ?

    cheers,

    G.
     
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  3. Jasdent

    Jasdent Mahonee

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    Nobody able to help me with this ?
     
  4. jojo

    jojo Looking for Boost!
    Staff Member Moderator quattro Audi S3

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    AFM is called a MAF on your Audi, a faulty one would make your pewerdelivery uneven, like the power is coming on and off throughout the rev range, or you may get the 'V-Tec' effect, where the power delivery comes in 2 stages at around 4k revs, this would suggest a intermittent MAF problem. f it's totally fooked, it will feel like the engines holding back when you give full throttle, the power seems to be there, but it won't unleash itself.
     
  5. DavidR

    DavidR Active Member

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    Best solution is to find one that works (off another car / new one) and swap them over. Reset the ECU and try the car again.

    If you have VAGCOM you can plot actual vs command boost pressure - if command is much higher than actual the MAF can be suspected.
     
  6. Jasdent

    Jasdent Mahonee

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    Yeah, I am thinking I have problems with it then. The car can quite often caomes and goes when I am accelerating and also get a choke effect when I stick the foot down.

    Anyone know the best place to get a new one at a decent price ? someone was telling me they quite often come p/xchange for the old unit, is this true ?

    Also is it just a case of changing it and everything should be fine ?

    cheers guys, lot of help !

    G.
     
  7. jojo

    jojo Looking for Boost!
    Staff Member Moderator quattro Audi S3

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    £80 exchange from your local Audi stealership bud, or just buy the sensor part from GSF parts for 55 quid or so, and you need a star bit to take the old one off.
     
  8. DavidR

    DavidR Active Member

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    Ebay, VAGPARTS, Eurocarparts etc...

    Change it (you'll need a fancy hollow torx bit for the newer cars), reset the ECU (pull the fuse or disconnect battery) and it should be fixed if the Maf was at fault.
     
  9. Jasdent

    Jasdent Mahonee

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    Perfect, cheers very much guys !

    any benefit in replacing the whole unit to just the sensor part ?
     
  10. rodenal

    rodenal Active Member

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    no point replacing the whole unit mate, sensor will do yo ufine
     
  11. Lord Vader

    Lord Vader Member

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    Do you have to reset the ecu, as i changed mine recently and suspected the new one to be faulty as when you reved the engine and allowed the revs to fall, it would try to stall , but then sort itself out. So i sent it back.

    Should i have reset the ecu and if so will this mess up any of the other settings in the car?

    Thanks
     
  12. jojo

    jojo Looking for Boost!
    Staff Member Moderator quattro Audi S3

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    No resetting needed, it's plug and play :)
     

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