EM TuningMonster Motorsport
Results 1 to 16 of 16
  1. #1
    Y83OLK's Avatar
    Hulk Smash!

    Status
    Offline
    Join Date
    Sep 2009
    Posts
    838

    Symptoms of a dodgy MAF?

    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

  2. # ADS
    ADS
    Join Date
    Always
    Posts
    Many
     
  3. #2
    finesse's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Aug 2006
    Location
    London / Anglia
    Posts
    2,814
    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



    Ibiza Cupra TDI

    Gone:

    Audi C5 RS 6 - Stage 2
    Audi 8L S3 - Revo'd

  4. #3
    Y83OLK's Avatar
    Hulk Smash!

    Status
    Offline
    Join Date
    Sep 2009
    Posts
    838
    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.

  5. #4
    sportquattro's Avatar
    4th Gear

    Status
    Offline
    Join Date
    Sep 2009
    Location
    Ivybridge, United Kingdom
    Posts
    717
    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
    1999 Audi S3 Superchips remap, Forge 007p, Phatnoise, Black Diamond Discs & DS2500 pads, N249 Deleted, Badger 5 TIP, Poly dogbone bush, Bilstein B8's and Eibach Springs.

    1986 Audi Coupe Quattro 2.2 restoration project

  6. #5
    Chugger

    Status
    Offline
    Join Date
    Nov 2009
    Location
    North Devon
    Posts
    2,716
    Quote Originally Posted by csweatherston View Post
    And at 5.5k rpm, its like hitting a brick wall.... Fuel cut?. (like when the esp comes in)
    Cheers
    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.
    57 A3 2.0 TDI Sportback (140)

  7. #6
    Y83OLK's Avatar
    Hulk Smash!

    Status
    Offline
    Join Date
    Sep 2009
    Posts
    838
    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.

  8. #7
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2009
    Location
    Gosport, Hants
    Posts
    367
    Interesting 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
    2003 Dolphin Grey S3, with a few mods....

  9. #8
    Y83OLK's Avatar
    Hulk Smash!

    Status
    Offline
    Join Date
    Sep 2009
    Posts
    838
    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

  10. #9
    finesse's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Aug 2006
    Location
    London / Anglia
    Posts
    2,814
    Quote Originally Posted by OllieH View Post
    Interesting 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
    Most/some people kick in from 2500RPM
    Ibiza Cupra TDI

    Gone:

    Audi C5 RS 6 - Stage 2
    Audi 8L S3 - Revo'd

  11. #10
    finesse's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Aug 2006
    Location
    London / Anglia
    Posts
    2,814
    Quote Originally Posted by csweatherston View Post
    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
    Bosch?
    Ibiza Cupra TDI

    Gone:

    Audi C5 RS 6 - Stage 2
    Audi 8L S3 - Revo'd

  12. #11
    Y83OLK's Avatar
    Hulk Smash!

    Status
    Offline
    Join Date
    Sep 2009
    Posts
    838
    OE.. should imagine its bosch.
    Partnumber 06A 906 461 MX (For a 2001 S3 AMK)

  13. #12
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2009
    Location
    Gosport, Hants
    Posts
    367
    Quote Originally Posted by finesse View Post
    Most/some people kick in from 2500RPM
    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
    2003 Dolphin Grey S3, with a few mods....

  14. #13
    finesse's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Aug 2006
    Location
    London / Anglia
    Posts
    2,814
    Quote Originally Posted by OllieH View Post
    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
    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/a...r_flow_sensors

    and

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

    Here's a good sanity check for the status of your MAF. Do a full-throttle run all the way to redline in a single gear (second works fine). Group 002 usually shows air mass in g/s (in many modern ECU's, consult your Factory Repair Manual for the specific group for your particular vehicle). Your peak airflow should be roughly 0.80 times your horsepower if you are close to sea level. So, if you have a stock 150 hp 1.8T, expect around 120 g/s. If you see significantly less than that, you MAF may be on the way out. Also note that airflow will be markedly different at higher altitudes due to reduced ambient air pressure, especially with naturally aspirated engines that do not have forced induction to overcome that deficiency. This still works if you are chipped, but "race" programs may make more power through timing, rather than airflow. Therefore, take all readings with a grain of salt.
    Good Luck!
    Last edited by finesse; 2nd May 2010 at 14:58.
    Ibiza Cupra TDI

    Gone:

    Audi C5 RS 6 - Stage 2
    Audi 8L S3 - Revo'd

  15. #14
    1st Gear

    Status
    Offline
    Join Date
    Nov 2007
    Posts
    158
    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

  16. #15
    Chugger

    Status
    Offline
    Join Date
    Nov 2009
    Location
    North Devon
    Posts
    2,716
    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
    57 A3 2.0 TDI Sportback (140)

  17. #16
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Finland
    Posts
    131
    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.

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO