Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: MAF Hz (B5001)?

  1. #1
    Lifetime Member
    Join Date
    Oct 2003
    Posts
    505

    Default MAF Hz (B5001)?

    Why does the MAF Hz in Flashscan start at 1500Hz and not 750?

    In Edit it starts at 750 Hz. The cell count is different also.
    Not that I think I need this range ...just curious??
    TIA.

    Everyone have a great weekend!

    Cheers,
    joel

  2. #2
    EFILive Developer Site Admin Blacky's Avatar
    Join Date
    Mar 2003
    Posts
    9,505

    Default Re: MAF Hz (B5001)?

    Quote Originally Posted by bink
    Why does the MAF Hz in Flashscan start at 1500Hz and not 750?

    In Edit it starts at 750 Hz. The cell count is different also.
    Not that I think I need this range ...just curious??
    TIA.

    Everyone have a great weekend!

    Cheers,
    joel
    Maybe Ross can answer this better than I can. As far as I know, the table should start at 1500. Either Edit or EFILive is wrong. My money is on Edit being wrong. But since I don't know for *sure* - I'll try and find out.
    Paul

  3. #3
    Lifetime Member
    Join Date
    Oct 2003
    Posts
    505

    Default

    That was my guess. But I couldn't figure out the cell count -...... can they (not Ross :lol: ) just make this stuff up? Thanks for the quick reply.

    Cheers,
    joel

  4. #4
    Junior Member
    Join Date
    Jun 2004
    Posts
    12

    Default

    Even HP Tuners starts at 1500 also..

    Strange Edit has been out as long as it has and no one has mentioned this before.

    Loyde

  5. #5
    Lifetime Member GMPX's Avatar
    Join Date
    Apr 2003
    Posts
    13,148

    Default Re: MAF Hz (B5001)?

    Quote Originally Posted by bink
    Why does the MAF Hz in Flashscan start at 1500Hz and not 750?

    In Edit it starts at 750 Hz. The cell count is different also.
    Not that I think I need this range ...just curious??
    TIA.

    Everyone have a great weekend!

    Cheers,
    joel
    Because they got it wrong, plain and simple.

    Cheers,
    Ross

  6. #6
    Lifetime Member
    Join Date
    Oct 2003
    Posts
    505

    Default Re: MAF Hz (B5001)?

    Quote Originally Posted by GMPX



    Because they got it wrong, plain and simple.

    Cheers,
    Ross
    Hi Ross,

    That's what I figured.....just wanted confirmation.
    As you know I know zip about coding. I can understand how one could Mislabel a table (i.e. IAC vs ECT instead of IAT) or have the range of cells incorrect ( RAF was originally scaled in 20*C increments). But how can you end up with an excess of cells, and the values, that don't exist??
    Thanks for the reply!
    Cheers,
    joel

  7. #7
    Lifetime Member GMPX's Avatar
    Join Date
    Apr 2003
    Posts
    13,148

    Default

    They are actually using some values from a table just before the MAF table!!.
    You just need to look at the actual values to see it just doesn't look right.

    Cheers,
    Ross

  8. #8
    Lifetime Member
    Join Date
    Sep 2003
    Posts
    688

    Default

    Quote Originally Posted by GMPX
    They are actually using some values from a table just before the MAF table!!.
    You just need to look at the actual values to see it just doesn't look right.

    Cheers,
    Ross


    Now that is just down right dirty. I wonder what else they FUBAR'd along with the fan temp settings and gear/tire (read this somewhere)

  9. #9
    Lifetime Member GMPX's Avatar
    Join Date
    Apr 2003
    Posts
    13,148

    Default

    I've had a few Emails and PM's about this MAF table thing...
    Here's the only way I can prove it.
    If you know nothing about assembler code then you might be a little lost with this -

    This is all taken from a 2001 LS1 O.S.

    First up, the issue is, does the MAF table contain 85 entries or 101.
    I believe 85 is correct.

    Here in this screen shot you can see two specific table starting address's.
    First one is at $E2E2, the second is at $E302.


    The routines that reference these two tables are totally seperate.
    For the table at $E2E2 -
    This command tblu is a "Table lookup" command starting at address $E2E2.


    The next routine is looking at the table at $E302 (The MAF Flow table).


    The final shot shows where the MAF table ends (address $E3AA).


    So to get a table size you just do the following maths -
    Table ends at $E3AC and starts at $E302.
    So $E3AC minus $E302 = $AA or 170 in decimal.
    However as the values are 16bit we divide by 2, so we get 85

    If we were to apply that same theory starting from address $E2E2 we end up with a table size of $C8 or 202, divide by 2 and we get 101.

    In any case, the values between the end of the first table and the start of the MAF table are VERY different.



    Cheers,
    Ross

  10. #10
    EFILive Developer Site Admin Blacky's Avatar
    Join Date
    Mar 2003
    Posts
    9,505

    Default


    Now I've really got a headache - I'm glad I only have to write the PC code
    Paul

Page 1 of 2 12 LastLast

Similar Threads

  1. ? on tweaking B5001
    By Chalky in forum General (Petrol, Gas, Ethanol)
    Replies: 2
    Last Post: June 4th, 2008, 03:54 PM
  2. MAF and B5001 Questions
    By Dale in forum General (Petrol, Gas, Ethanol)
    Replies: 2
    Last Post: November 22nd, 2007, 10:51 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •