ALDL Tuning

[Malcolm Robb, LC 0112G]

Something has just occurred to me. Both Ludis and BobR have said that they 
haven't looked closely at the P4 ALDL code. Well something I have noticed 
is that (in my EPROM mask at least) it is possible to set the desired 
Air/Fuel mixture and the desired Spark Advance/Retard by using ALDL Mode 4. 
In other words, you can override the values calculated by the ECU and force 
it to use what you want. I've always been too scared to try this on my own 
car, because it would cost a lot to fix if I broke something.

Both the air/fuel mix and the spark can be set to an absolute value (i.e. 
command 14.7 A/F or 10Deg spark) , or  to delta values (i.e. ECU calculated 
+/- something)

I hope I'm not teaching grandma to suck eggs, but wouldn't this ease the 
tuning of engines at given revs ? I haven't seen any comment about software 
packages invoking these Mode 4 commands, so I just thought I'd run the idea 
up the flag pole and see if anyone saluted it.

Cheers,
Malcolm Robb, LC 0112G

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