$da2 on 93 lt1 vette: no spark retards vs. inlet air temp ?i

dizwiz24 · Post by **dizwiz24** » Wed Jul 27, 2011 12:41 pm

Im finding my supercharged/meth injected 93 vette is pulling timing not related to knock retard...

The service manual confirms that the ecm can pull timing based on knock and inlet air temp.

I've relocated my iat sensor to ambient air (vs. Supercharged air) but still get some knock retard.

There is a mat compensation counts vs. Iat, but im not sure what that table does.

I can't find a table related to spark retard vs. Iat temp on this$ da2.

There has to be one somewhere...can anyone help me out?

How hard what it be to add this to$ da2....

Post by **robertisaar** » Tue Jan 17, 2012 10:30 pm

service manuals are sometimes quite optimistic about explaining how the
ECMs work... it will pull timing based on knock(they all do), but based on IAT is mask dependant.

moving the sensor to where it measures ambient air is lying to the ECM, specifically telling it that the real air-mass is denser than what it really is. this does two things: increases fuel delivery, and usually increases spark advance as well(if the mask cares about IATs for SA, anyways)

MAT compensation counts vs IAT isn't what you're looking for, but i don't know if DA2 has any native "spark advance vs IAT" tables.

i added that specifically in myself for A1(which after all of the work i've put into it, i've renamed nAst1), along with plenty of other stuff.

assuming there is some decent PROM space left, i don't think it would take me too long to add that table in. i think i have a basic disassembly already created, but it would be best to generate a patched file directly off of the BIN you're running. PM me as much info as you can/what you want done, and i'll see what i can do.

EagleMark · Post by **EagleMark** » Mon Jan 23, 2012 9:30 am

I think I have a dissasembly of $DA3...

Post by **robertisaar** » Mon Feb 20, 2012 5:45 pm

EagleMark wrote:I think I have a dissasembly of $DA3...

i was rather bored for a few hours and did BASIC disassemblies of almost every mask that runs on a 6811. so technically, i do now, but it's nowhere near complete.

IDA Pro is just all kinds of awesome for stuff like that.

EagleMark · Post by **EagleMark** » Mon Feb 20, 2012 6:52 pm

Yeah but the price scared the heck out of me? I'm trying to save enough to buy OBDII tuning software....

Post by **robertisaar** » Mon Feb 20, 2012 7:02 pm

yeah.... i got quite a deal on it...

dizwiz24 · Post by **dizwiz24** » Sun Mar 11, 2012 6:27 pm

Ok. I sent you a pm