RE: BLM cell boundaries, Was: EPROM Programming

[Mika.Helander@softbit.fi]

<snip>

> Say the Rpm and MAP boundaries are set at:
> 
> MAP   25, 60, 80 kPa   
> 
> RPM  1000, 1450, 2200 
> 
> These values were taken from a 747 PROM I have.
> 
> 
> 
> Use a non-proportional font here, to get the spacing right.
> 
> 
>                        BLM Cell Matrix
> 
> MAP boundary   
> 
>      100 kPa---------------------------------------------
>                |        |          |          |         |
>                |   12   |    13    |    14    |    15   | 
>                |        |          |          |         |
>       80 kPa---|--------|----------|----------|---------|
>                |        |          |          |         |
>                |    8   |     9    |    10    |    11   |
>                |        |          |          |         |
>       60 kPa---|--------|----------|----------|---------|
>                |        |          |          |         |
>                |    4   |     5    |     6    |     7   |
>                |        |          |          |         |
>       25 kPa---|--------|----------|----------|---------|
>                |        |          |          |         |
>                |    0   |     1    |     2    |     3   |
>                |        |          |          |         |
>        0 kPa---|--------|----------|----------|---------|
>                |        |          |          |         |
> RPM boundary   0       1000       1450      2200       6375

To refer 7747_asdz_hack.pdf there is following values:

                       BLM Cell Matrix

MAP boundary   

     100 kPa---------------------------------------------
               |        |          |          |         |
               |   12   |    13    |    14    |    15   | 
               |        |          |          |         |
      81 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
               |    8   |     9    |    10    |    11   |
               |        |          |          |         |
      58 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
               |    4   |     5    |     6    |     7   |
               |        |          |          |         |
      18 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
               |    0   |     1    |     2    |     3   |
               |        |          |          |         |
       0 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
RPM boundary   0        750       1800      2600       6375

And location LD29C reflects to 99.3 kPa (kPa MAP upper thresh for BLM) and
location LD2B1 81.2 kPa (highest BLM Cell Boundry).

<snip>

> If you set the last MAP boundary at 90 kPa, and then set
> the "max MAP to learn" limit at 89 kPa, cells 12,13,14,15 
> will always stay at 128, the neutral value.

So do you mean that changing location LD29C to reflect 89 kPa and location
LD2B1 to reflect 89 Kpa?

> This will you to keep from using a learned value at WOT,
> if this is what you need.

And the idea is at WOT (>89 kPa MAP) to tell '7747 to calculate fueling
according to EPROM settings, without BLM messing?

What about other tables in EPROM? Are other changes needed to "match" this
change?

And I'm assuming that for other cells BLM's and INT's are used when
correcting EPROM tables, but WOT is a bit problematic because O2 doesn't
keep up there (wide band O2, or reading spark plugs?).

> This is what I was driving at.

Any change to "see" Your EPROM contents? Application?

And if anyone having any templates/tools to convert '7747 disassembly to
commented one a'ka 7747_asdz_hack.pdf with formulas etc?

> Scot Sealander

-Mika
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