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MAF readings are low....is this correct?

Discussion in 'A3/S3 Forum (8L Chassis)' started by g10chy, Jan 11, 2011.

  1. g10chy
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    g10chy Member

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    [Jan 11, 2011]
    I had a MAF error few weeks back which was cleared and has not returned since. Is a reading of 10.7g/s at 3k revs standstill correct? Or is my MAF on it's way out?

    Cheers,
    Chris
    Last edited: Jan 11, 2011
    #1
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  3. DaveA3
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    DaveA3 Audi A-Trizzle!

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    [Jan 11, 2011]
    u need to go for a spirited drive. try to get max revs 6500ish in 3rd gear. ull get proper readings then. too hard to compare revving on ur drive like.
    #2
  4. g10chy
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    g10chy Member

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    [Jan 11, 2011]
    Theses are some of my readings from 4k to 6k full load. How do these look?

    RPM Inj. On Timing Mass Flow g/s
    4440 150.4 143.28
    4840 155.6 144.86
    5240 149.6 147.06
    5560 142.1 152.33
    5880 133.8 144.83
    Last edited: Jan 11, 2011
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  5. Welly
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    Welly VX220 SC Driver :)

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    [Jan 11, 2011]
    You need to do the readings to redline to be honest mate. Up to 6K isn't really that helpful.

    Considering that though, the readings are low, even at 6K for a remapped car.

    3rd gear, 3K to redline will give a good reading of the airflow - then post them up.
    #4
  6. g10chy
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    g10chy Member

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    [Jan 11, 2011]
    OK cheers Welly. I will try and borrow my mates cable overnight so I can get some proper runs logged and uploaded.

    Could it be that I simply have a sh!te remap? As my boost pressures seemed abit low also averaging between 17-20 psi with WOT!
    #5
  7. Welly
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    Welly VX220 SC Driver :)

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    [Jan 11, 2011]
    Well, it's a bit hard to say. The values are low. You are making around 190 bhp at the best point of the values you posted.

    Could be a dying MAF, could be the map... But it would have to be an epicially bad map, as looking at what you posted before, it will struggle to make standard power.
    #6
  8. g10chy
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    g10chy Member

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    [Jan 11, 2011]
    Welly - Could I email you the full log which has group 115 and 002 for the quick test run i performed for you to cast your eye over a bit more? Quite worried i've not been reaching its potential for quite sometime now :(
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  9. Welly
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    Welly VX220 SC Driver :)

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    [Jan 11, 2011]
    Yep, no problem, I'll PM you my email address.
    #8
  10. g10chy
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    g10chy Member

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    [Jan 11, 2011]
    Cheers man. I have just sent you the log.
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  11. Prawn
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    Prawn My other car is a MINI!!!!

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    [Jan 11, 2011]
    Those airflow figures sound really low to me. especially for a mapped S3!

    Even without going to the redline, here's a tiny extract from the one log I could find on my work PC.

    This is a ko3S turbo too, not a ko4.

    RPM Airflow (g/s)

    4120 150.07
    5080 173.75
    5840 186.39
    6560 187.15

    So that's just an A3, and at 5000rpm it's making almost 20g/s more than you're mapped S3! something big time wrong there.....
    #10
  12. Welly
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    Welly VX220 SC Driver :)

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    [Jan 11, 2011]
    OK, looking at that log, the airflow does look to be down, but it's difficult to be sure because it never gets to redline, and all the bursts of acceleration are short.

    If you can, go out again and log block 002, 020 and 115. Timing pull (020) is a useful block to log because it gives you a better insight as to what is going on.

    Try, again if you can, to do a several full runs in 3rd (or 4th if you are brave enough) from 3K all the way to 7K. Nice log logs are easier to gets useful info from.
    #11
  13. Welly
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    Welly VX220 SC Driver :)

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    [Jan 11, 2011]
    Agreed, mapped S3s should be expecting 200 g/s or close to.
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  14. Welly
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    Welly VX220 SC Driver :)

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    [Jan 11, 2011]
    Again, here is a brief excerpt from one of my very old Stage 1 REVO logs:

    Code:
    
    	RPM	Inj. On Time	Mass Flow
    TIME			
    STAMP	 /min	 ms	 g/s
    165.28	5600	19.27	194.69
    166.48	5840	18.86	199.25
    167.68	6080	18.04	198.92
    168.98	6320	16.81	194.42
    170.29	6520	16.4	189.42
    171.49	6680	15.99	191.64
    
    I have sent you the whole log for comparison.
    #13
  15. g10chy
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    g10chy Member

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    [Jan 11, 2011]
    Welly - Nice one for looking...I am borriowing my mates cable tonight so I will get some better runs logged. The roads were too busy this lunch to get any decent runs!!

    Will be in touch later.

    Cheers,
    Chris
    #14
  16. Welly
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    Welly VX220 SC Driver :)

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    [Jan 11, 2011]
    As per my email back mate, with standard S3 210 log attached for your reference.
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  17. JD09
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    JD09 I'm not modding, I'm improving VCDS Map User

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    [Jan 11, 2011]
    I still want to know why I got 186 from a standard car.
    #16
  18. superkarl
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    superkarl MAN OF STEEL

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    [Jan 11, 2011]
    There was a hurricane that day that was blowing into your maf for a brief moment.
    Just a guess like
    #17
  19. Breezey
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    Breezey Member

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    [Jan 11, 2011]
    I got 181 from my standard S3, yours must be running that little bit better.
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  20. g10chy
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    g10chy Member

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    [Jan 11, 2011]
    Welly - I have just done a run in 3rd from 3k to redline....not looking good :sadlike: I have sent you the full log but the max MAF reading im getting is 159.5g/s!!!

    Im also getting a few Idle Stabilization figures which im guessing is not good also?

    Any ideas whats wrong?


    Cheers,
    Chris
    Last edited: Jan 11, 2011
    #19
  21. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Jan 12, 2011]
    tired maf... most likely
    #20
  22. Welly
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    Welly VX220 SC Driver :)

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    [Jan 12, 2011]
    Lots of timing pull on the logs as well though. Not horrendous, but seeing 6s.
    #21
  23. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jan 12, 2011]
    If the maf's tired wouldnt the fuelling be all over the shop though?

    Running lean will cause timing pull?
    #22
  24. Welly
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    Welly VX220 SC Driver :)

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    [Jan 12, 2011]
    Yep, it's got dodgy MAF written all over it....
    #23
  25. g10chy
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    g10chy Member

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    [Jan 12, 2011]
    OK nice one guys!

    Will the below part be OK or should I get and OEM one direct from Audi?

    HTML:
    http://www.eurocarparts.com/ecp/c/Audi_S3_1.8_2001/p/car-parts/engine-parts/fuel-and-engine-management/engine-management-sensor/?434440150&1&a413bd08cf642550236330dbb8c7f97fc7dcaf12&AFME
    #24
  26. Welly
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    Welly VX220 SC Driver :)

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    [Jan 12, 2011]
    That one should be OK, as long as it's a genuine Bosch unit it will be fine. Check that with them beforehand.

    EDIT: Is does distinctly say 'Bosch' on the listing, so should be fine...
    #25
  27. JD09
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    JD09 I'm not modding, I'm improving VCDS Map User

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    [Jan 12, 2011]
    I'm going to log again tonight and see what mine is now getting.
    #26
  28. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Jan 12, 2011]
    it wont be helping the fuel trims... but if wideband car it will still be controlled by lambda
    #27
  29. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Jan 12, 2011]
    yes.. seen it a lot
    #28
  30. g10chy
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    g10chy Member

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    [Jan 12, 2011]
    Getting my mate at Audi order me a new MAF....Discounted parts :thumbsup:

    Will then do another log to see if the MAF readings have improved!!! Fingers crossed
    #29
  31. Welly
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    Welly VX220 SC Driver :)

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    [Jan 12, 2011]
    Good luck dude, hope it sorts it for you. Should unlock some power for you.... :thumbsup:
    #30
  32. g10chy
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    g10chy Member

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    [Jan 19, 2011]
    Just fitted the new MAF and performed a new run feels alot better!!

    How do I get the results from Excel into the post without losing the formatting?

    Cheers,
    Chris
    Last edited: Jan 19, 2011
    #31
  33. Welly
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    Welly VX220 SC Driver :)

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    [Jan 19, 2011]
    Chris, as per my email reply, there is still a little extra timing pull than is ideal. 6s are generally considered to be the limit of safe with regard to timing pull.

    I would take your top hoses off to check for oil inside - excess oil in the charge system can often cause higher than average timing pull figures. If there is a lot of oil, clean out as best as you can and then re log. Then keep an eye on the amount of oil in the charge system.

    I notice that it is only under heavy load in high gear, so you may want to avoid doing this too much until resolved. Ideally the timing wants to be backed down a little bit. Who mapped it?

    MAF readings are much better - a massive improvement. I would imagine there is an improvement on the road as well?

    Nice work - glad that the MAF problem has gone.
    #32

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