Cranking injector pulse width

02-25-2012, 02:37 PM

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oltmann

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Cranking injector pulse width

I think I found a couple tables for setting cranking IPW based on coolant temp:

Code:

Table A
Coolant Temperature [c],Cranking IPW [us]
-30,123700
-25,121000
-20,112400
-10,65000
0,43300
10,34700
20,28100
30,22000
40,17500
50,14200
60,11870
70,10170
80,8135

Table B
Coolant Temperature [c],Cranking IPW [us]
-30,123700
-20,112400
-10,65000
0,43300
10,34700
20,28100
30,22000
40,17500
50,14200
60,11870
70,10170
80,8135

They are shown here with the scaling from the rom, which looks to be microseconds, so divide by 1000 to get IPW in milliseconds.

There is also a table which acts as a multiplier to these values based on throttle position:

Code:

 [Throttle Position], [Multiplier]
21.02102,1
22.52252,0
100,0

So in the stock configuration it just disables this enrichment if you floor it, but there might be other interesting ways to set it up.

caveats
There are other checks against pedal position, throttle, ECT and unknowns, that can disable this enrichment. Also unknown is exactly under what circumstances table A or B will be used, and there are other modifiers to the final value, including some learned parameters, that I don't understand. This is all totally untested.

Almost forgot, I looked these up in some other roms for reference:

Code:

Series II 2010 MT USDM
-30,91230
-25,89240
-20,82895
-10,47940
0,31935
10,25590
20,20725
30,16225
40,12905
50,10475
60,8755
70,7500
80,6000

Very early JDM
-30,123745
-25,121030
-20,118310
-10,103220
0,90130
10,72270
20,46835
30,35465
40,25140
50,17450
60,11870
70,10170
80,8475

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