Deceleration Fueling / Overrun RPM cutoff threshold tables

td-d · **Posted:** Sun Jul 22, 2012 9:30 pm

Sasha_A80 wrote:

Thanks a lot.

But I still do not understand the meaning of the second table found.
It looks like another branch for fuel overrun threshold tables.

There was no this altenative table within 512KB ROMs I had observed.

The last six are definately IdleRPM tables.

I'm not sure - it's not referenced in that branch of the deceleration fueling code, only much later in the code.

td-d · **Posted:** Sun Jul 22, 2012 10:12 pm

Hmmm... here's an idea - weird synchronicity, I was just asked to see if I could identify if there is any injector timing tables or related parameters.

If you follow the same (2nd) table in AZ1G101N back to the subroutine, there is another table in there that seems to be related to the injectors (and is in close proximity to the injector latency table). I wonder if it's related to injector phasing...

dschultz · **Posted:** Mon Jul 23, 2012 3:21 am

Question: are the injectors synchronized to each cylinder like the timing for spark is, or do the injectors just batch fire all the time with no regard to cylinder timing?

Sasha_A80 · **Posted:** Mon Jul 23, 2012 4:55 am

In steady state air flow injectors are synchronized to each cylinder, but the value of phase advance\retard is not very important (there are too many speculations around the "optimal" phasing). It shoud just be stable and not change rapidly against RPM\load, any fixed value is not too bad.

But. "Light" fuel tip-in needed depends on injector phasing since the balance of fuel currently injected and come from the manifold varies into the cylinder within the current intake cycle.

"Huge" amounts of tip-in enrichment fuel are usually "batch" injected asynchronized in order to speedup manifold wall wetting and to compensate mixture enleanment sooner.

mrf582 · **Posted:** Tue Jul 31, 2012 8:16 pm

Do you know the address for USDM 2006 WRX A8DH201X?

TIA!

td-d · **Posted:** Tue Jul 31, 2012 8:52 pm

mrf582 wrote:

Do you know the address for USDM 2006 WRX A8DH201X?

TIA!

No problem.

Here they are - RPM delta and initial pulsewidth

Code:

ROM:000C8744 flt_C8744:      .float -17.0            ; DATA XREF: sub_32F9A+46o
ROM:000C8744                                         ; ROM:off_331D8o
ROM:000C8748 flt_C8748:      .float 1400.0           ; DATA XREF: sub_32F9A+66o
ROM:000C8748                                         ; ROM:off_331E4o

RPM counters:

Code:

ROM:000C8790 flt_C8790:      .float 1700.0           ; DATA XREF: sub_33984:loc_339CAo
ROM:000C8790                                         ; sub_33AEE:off_33BBCo
ROM:000C8794 flt_C8794:      .float 2500.0           ; DATA XREF: sub_33984:loc_339D8o
ROM:000C8794                                         ; sub_33AEE:off_33BC0o
ROM:000C8798 flt_C8798:      .float 3000.0           ; DATA XREF: sub_33984:loc_339E6o
ROM:000C8798                                         ; sub_33AEE:off_33BC4o

And the resume table:

Code:

ROM:000950C0 word_950C0:     .data.w h'10            ; DATA XREF: sub_33448:loc_335F0o
ROM:000950C0                                         ; sub_33448:off_336BCo
ROM:000950C2                 .data.w h'800
ROM:000950C4                 .data.l h'C8974
ROM:000950C8                 .data.l word_C97F0
ROM:000950CC                 .float 0.1953125
ROM:000950D0                 .float 0.0

mrf582 · **Posted:** Tue Jul 31, 2012 11:11 pm

Thank you very much. I think I figured out the syntax for most of the tables but am having no luck figuring it out for the Overrun Resume table. Can you help? This is what I have that works.

Code:

A8DH201X

   <table name="Overrun_Enrich_RPM_Delta_Activation" address="C8744" type="1D" level="1" scaling="rawecuvalue"/>

   <table name="Overrun_initial_enrichment" address="C8748" type="1D" level="1" scaling="ms"/>

   <table name="Overrun_Fueling_Cut_Counter_RPM_Threshold" address="C8790" type="2D" level="1" scaling="RPM">
      <table name="RPM" type="Static X Axis" elements="3">
         <data>Low</data>
         <data>Med</data>
         <data>High</data>
      </table>
   </table>

Overrun_Enrich_RPM_Delta_Activation - What are the units for this? Is this -17RPM?
Overrun_initial_enrichment - Is this used during the first firing when the injectors come back on after coasting or is this the IPW during coasting if RPM is below the Overrun Resume RPM?
Overrun_Fueling_Cut_Counter_RPM_Threshold - how is this used?

td-d · **Posted:** Wed Aug 01, 2012 12:07 am

mrf582 wrote:

Thank you very much. I think I figured out the syntax for most of the tables but am having no luck figuring it out for the Overrun Resume table. Can you help? This is what I have that works.

Overrun_Enrich_RPM_Delta_Activation - What are the units for this? Is this -17RPM? - Yes, rpm delta required for overrun mode to kick in
Overrun_initial_enrichment - Is this used during the first firing when the injectors come back on after coasting or is this the IPW during coasting if RPM is below the Overrun Resume RPM? Neither - it's the first firing just before injector switch off - I.e. tip out
Overrun_Fueling_Cut_Counter_RPM_Threshold - how is this used?
These are a set of rpm thresholds that are used by multiple counters in determining when fuel cut will happens during overrun mode.

The resume table looks like an idle table basically - ECT on x axis, and rpm values in the tables - so at operating ECT injectors will only resume firing at 900 rpms.

mrf582 · **Posted:** Wed Aug 01, 2012 1:09 am

Can you help me define the syntax for Overrun Fueling Resume? I tried putting in addresses into the template you have in your first post but I get nothing that looks like RPM and ECT to display.

<scaling name="OverRun Fueling " units="units" toexpr="x*0.1953125" frexpr="x/0.1953125" format="%.0f" min="0" max="255" inc="1" storagetype="uint16" endian="big"/>

<table name="Overrun Fueling RPM Threshold" address="ca8d4" type="2D" level="1" scaling="OverRun Fueling ">
<table name="X" address="c7ff4" type="X Axis" elements="16" scaling="DegreesF"/>
</table>

I don't know what addresses to replace the bold part with... I tried 950C0 and it didn't work. I'm probably doing something wrong.

td-d · **Posted:** Wed Aug 01, 2012 5:58 am

No prob - table value is C8974
X axis value is C97F0

The scaling you have is right - the location it's at is the lookup table, not the actual data and axis (those are in the actual LUT).

mrf582 · **Posted:** Wed Aug 01, 2012 1:57 pm

Please see the attached image for what my data looks like... Is there something wrong on my end? What?

td-d · **Posted:** Wed Aug 01, 2012 5:30 pm

Sorry - I flipped the values around - the table value is C97F0 and the X axis is C8974.

I.e. in ecuflash

Code:

   <scaling name="overrun" units="units" toexpr="x*0.1953125" frexpr="x/0.1953125" format="%.0f" min="0" max="255" inc="1" storagetype="int16" endian="big"/>

   <table name="Over run fueling " address="c97f0" type="2D" level="1" scaling="overrun">
      <table name="Engine Coolant Temperature" address="c8974" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
   </table>

mrf582 · **Posted:** Wed Aug 01, 2012 5:45 pm

Oh, it's so beautiful!

Thanks!

Going to post the ECUFlash code for all tables defined in this thread for 2006 WRX A8DH201X. I think it works for A8DH200X too.

Code:

A8DH201X

   <scaling name="overrun" units="units" toexpr="x*0.1953125" frexpr="x/0.1953125" format="%.0f" min="0" max="255" inc="1" storagetype="int16" endian="big"/>

   <table name="Over run fueling " address="c97f0" type="2D" level="1" scaling="overrun">
      <table name="Engine Coolant Temperature" address="c8974" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
   </table>

   <table name="Overrun_Enrich_RPM_Delta_Activation" address="C8744" type="1D" level="1" scaling="rawecuvalue"/>

   <table name="Overrun_initial_enrichment" address="C8748" type="1D" level="1" scaling="ms"/>

   <table name="Overrun_Fueling_Cut_Counter_RPM_Threshold" address="C8790" type="2D" level="1" scaling="RPM">
      <table name="RPM" type="Static X Axis" elements="3">
         <data>Low</data>
         <data>Med</data>
         <data>High</data>
      </table>
   </table>

paryav · **Joined:** Tue Jul 24, 2012 9:12 am **Posts:** 2

A2WC401F

<scaling name="overrun" units="units" toexpr="x*0.1953125" frexpr="x/0.1953125" format="%.0f" min="0" max="255" inc="1" storagetype="int16" endian="big"/>

<table name="Over run fueling " address="62968" type="2D" level="1" scaling="overrun">
<table name="Engine Coolant Temperature" address="61cb4" type="X Axis" elements="16" scaling="CoolantTemp(DegreesF)"/>
</table>

Last three not found.
Please help.

td-d · **Posted:** Sat Sep 01, 2012 9:25 am

For Patrick, A8DK100P

Code:

RPM Delta C7920 
Initial overrun enrichment C7924 

ROM:000C796C Overun_Counter: .float 1600.0        
ROM:000C7970 flt_C7970:      .float 2000.0         
ROM:000C7974 flt_C7974:      .float 2500.0       

Overun_Fueling_RPM_Resume
ECT (x Axis) C7A24
Resume threshold (table values) C8C8C

RomRaider

Deceleration Fueling / Overrun RPM cutoff threshold tables

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