MAF BLM based tuning

[Scot Sealander]

Dave Zug wrote:
 
> (This is for MAF '165 ARAP... 383 app)

Is is a stock MAF?  Not gutted?


> Given that the BLM cell seperators are 13,21,34 g/s, and 700,1200,2000
> RPM...

So the MAP looks like this:  (Whoops, used MAP!)  :-)

AirFlow                  BLM Cell

34 to 255    12       13         14        15

 
21 to 34      8        9         10        11


13 to 21      4        5          6         7

   
0 to 13       0        1          2         3     


    RPM ->  0-700   700-1200  1200-2000  2000-6375     

 
> and as an example, say cells 6 and 10 show high values (160)  and the rest
> are fine (low 130's).

Is this a real example?  Then only at 1200 to 2000 RPM and between 13
and 
34 gps you do have a problem.  Why not cell 2 or 14 ?   A BLM rise to
160 
represents a 25% error in the MAF reading.  That is a big error.  Is
there 
a vacuum leak?  Like the can purge hose is off? This would create a big 
leak that would make the BLMs climb, and probably only in those cells.
Disable the CP and see what happens.

If you are truly grtting 160 BLMs, I would look for something wrong
before
trying to recal the MAF tables.

 
> Since I have no VE tables to speak of,  What would be a good first step in
> settling the bad BLM's back to normal, without affecting the rest of the
> good BLM's?

Make SURE everything is OK before trying to re-cal. I think if you
re-cal,
you may find a cell 2 or 14 problem.  Try disabling the Can Purge and/or
EGR and anything else that may interfere before trying to re-cal.
If this is not a problem, slowly change the MAF table values around
the troubled airflows, 13 to 34 gps.

 
> Please respond without using the word "MAP"   ;-P

Sorry!

 
> Extra credit:  Anyone tried expanding or sliding the range that BLM's
> affect?  like 13,27,40 and 700,1600,2800?

I use just three cells.  At Idle, Off idle, or coasting.  And the 3rd is
not
really needed.

Scot Sealander
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