TwinTurbo.NET: Nissan 300ZX forum - That is a good point
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Subject That is a good point
     
Posted by LitlElvis on December 11, 2018 at 11:57 AM
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In Reply To That ecu was wastespark. Does that fit the logic maybe? (n/m) posted by kickerzx on December 11, 2018 at 12:07 AM
     
Message Since the ECU only has 5 coil drivers, it must be setup for wasted spark on any engine with more than 5 cylinders. Cylinders that fire 360° from each other are grouped together: 1 and 4, 2 and 5, 3 and 6. From what I have read, by assigning a CAS "tooth" to each cylinder this allows for individual ignition timing trim even though it is wasted spark. I made a mistake in my previous post listing how the firing order for the ignition is setup, this is a more accurate table showing all options:

Ign Tooth #01 = Coil 1 = cylinder #1 = 0 teeth
Ign Tooth #02 = Coil 2 = cylinder #2 = 4 teeth
Ign Tooth #03 = Coil 3 = cylinder #3 = 8 teeth
Ign Tooth #04 = Coil 4 = off
Ign Tooth #05 = Coil 5 = off
Ign Tooth #06 = Coil 1 = cylinder #4 = 12 teeth
Ign Tooth #07 = Coil 2 = cylinder #5 = 16 teeth
Ign Tooth #08 = Coil 3 = cylinder #6 = 20 teeth
Ign Tooth #09 = Coil 4 = off
Ign Tooth #10 = Coil 5 = off

The table above shows the wasted spark coil driver grouping and the firing order, but I don't believe this logic follows over to the Injector table because the ECU has 10 injector drivers.

Fleshing out the injector table to show the correlation between tooth #, injector #, and cylinder # gives this full table:

Inj Tooth #01 = Injector #1 = cylinder #1 = 12 teeth
Inj Tooth #02 = Injector #2 = cylinder #2 = 4 teeth
Inj Tooth #03 = Injector #3 = cylinder #3 = 20 teeth
Inj Tooth #04 = Injector #4 = cylinder #4 = 8 teeth
Inj Tooth #05 = Injector #5 = cylinder #5 = 16 teeth
Inj Tooth #06 = Injector #6 = cylinder #6 = 0 teeth
Inj Tooth #07 = Injector #7 = off
Inj Tooth #08 = Injector #8 = off
Inj Tooth #09 = Injector #9 = off
Inj Tooth #10 = Injector #10 = off

But the tooth increment per cylinder still doesn't follow the expected firing order.

     
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