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Symptoms of a dodgy MAF?

Discussion in 'A3/S3 Forum (8L Chassis)' started by Y83OLK, May 1, 2010.

  1. Y83OLK
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    Y83OLK Hulk Smash!

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    [May 1, 2010]
    Hi all.
    Whats all the symptoms of a dodgy maf?.

    Last time i VAG-com'd it, my maf was reading a little bit low (compared to "sportquatro's")
    Peaked at 190g/s.....Stage 1 map.
    Now, my fuel consumptions down to < 20mpg.

    And at 5.5k rpm, its like hitting a brick wall.... Fuel cut?. (like when the esp comes in)

    Ive got the new MAF here infront of me (impulse buy)
    Just wondering if all of the above are common symptoms.

    Cheers
    #1
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  3. finesse
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    finesse Active Member VCDS Map User

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    [May 1, 2010]
    Did you buy a genuine Bosch MAF?

    Dodgy MAF - Rough Running At Idle, Cold Start Problems, MPG, Running Rich/Lean

    Have a look;
    Diagnosing a bad MAF


    [​IMG]
    #2
  4. Y83OLK
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    Y83OLK Hulk Smash!

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    [May 1, 2010]
    Cheers finesse... Pics been saved for future reference.lol
    I think ill need to get a new battery in the laptop, and see what 006 is reading.
    #3
  5. sportquattro
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    sportquattro Active Member

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    [May 1, 2010]
    Hi Callum, Have you tried running it with the MAF unplugged? It wont Idle very well but, if it revs and performs as it should then you know it a MAF issue. Economy should be a lot better than <20mpg. If you want to do some back to back comparisons with mine on VAG-COM just shout and I'l pop over.

    Nige
    #4
  6. sportstractor
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    sportstractor Chugger

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    [May 2, 2010]
    could be loads of things, but sounds ignition related to me. Spark plugs coilpacks been changed recently? Some times if plugs are lacking power etc the spark can be 'blown out' at certain rpm and it feels alot like an engine limiter.
    #5
  7. Y83OLK
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    Y83OLK Hulk Smash!

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    [May 2, 2010]
    Well, i braved the weather and stuck my new MAF on thismorning.
    Just been out for a hoon.. And it goes like stink now.
    Boost comes in just below 3k (before it was 3.5) boost runs out around 5k.. But still pulls well till 6.

    Happy with that, just need to check the fuel consumption now lol.
    #6
  8. OllieH
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    OllieH Member

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    [May 2, 2010]
    Interesting:think: I might have to change my MAF. I can hear my turbo boosting up from 2.5k rpm but don't get the kick until 3,200 rpm+. I can't find any leaks and the plugs and coilpacks are all new. How much was your MAF?

    P.s. Glad you got it sorted :icon_thumright:
    #7
  9. Y83OLK
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    Y83OLK Hulk Smash!

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    [May 2, 2010]
    Hi mate.
    I got it trade for £61.
    But theres a £20 surcharge on the old unit.

    RRP is £79.90 +£20 + Vat Through TPS
    #8
  10. finesse
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    finesse Active Member VCDS Map User

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    [May 2, 2010]
    Most/some people kick in from 2500RPM
    #9
  11. finesse
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    finesse Active Member VCDS Map User

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    [May 2, 2010]
    Bosch?
    #10
  12. Y83OLK
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    Y83OLK Hulk Smash!

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    [May 2, 2010]
    OE.. should imagine its bosch.
    Partnumber 06A 906 461 MX (For a 2001 S3 AMK)
    #11
  13. OllieH
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    OllieH Member

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    [May 2, 2010]
    Mine used to until I had a coilpack go a couple of months ago, and ever since the kick doesn't come in until 3,200+. Have since changed all coilpacks and plugs, have looked for boost leaks, so next thing will be MAF I think.

    Sorry for stealing the thread :icon_thumright:
    #12
  14. finesse
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    finesse Active Member VCDS Map User

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    [May 2, 2010]
    MAF is relatively expensive so take vagcom logs to gauge the general health before replacing, if you do, make sure you get a genuine Bosch MAF; 06A 906 461 M


    http://autotechrepair.suite101.com/article.cfm/mass_air_flow_sensors

    and

    http://wiki.ross-tech.com/wiki/index.php/Fuel_Trim_Info

    Good Luck!
    Last edited: May 2, 2010
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  15. StrmsekS3
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    StrmsekS3 Member

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    [May 9, 2010]
    Hello, looking to pick someones brains, my 2002 S3 has twice now when started run rough (idles much higher than normal and is not steady idle) this has only happend twice once from cold start and other car had driven 2 hrs stopped for 4 hrs then started again and it happend, i dont use the s3 often but wondering if it may be the MAF?? dont have access to vagcom.

    anyone had the same or know what it may be?

    cheers
    #14
  16. sportstractor
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    sportstractor Chugger

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    [May 9, 2010]
    same thing was happening to me, started playing up after a smoke test i had done on it. Would only happen sometimes when starting from cold and would be erratic. When I changed the maf it all went away
    #15
  17. BuuBBa
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    BuuBBa Member

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    [Jan 16, 2013]
    Could MAF be end of its life time even though the readings seems fine? Car has rough idle sometimes and is running rich. I unplugged the MAF and the engine coughed two seconds and then came back "normal". Couldnt find any boost leaks and the PCV check valve is new.
    #16

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