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View Full Version : Timing(maybe fuel) plumits when a4 shifts



acomp917
February 8th, 2010, 04:13 PM
Hello All,

Just to the point of being able to log/bbl an upgraded 2k to 2002 silverado pcm. I'm starting to become familiar with the tables... all 2 million of them. :shock:

I noticed exactly the same thing on the 2k tune. The O2's don't rise during shift(reduced timing, would cause this if the fuel did not cut), they seem to lower momentarily. If I had to guess... it looks like torque limit.

Anybody seem anything like this? Do you know the cause?

This thing is COMPLICATED! I'm really starting to appreciate the software and the efforts of the developers logic/programming. Takes a lot of getting used to, although it allows the user to analyze the PCM in endless ways.

Thanks for any help,
S

joecar
February 8th, 2010, 04:18 PM
In the transmission section of the file, look at "Torque Reduction"...

on each shift it reduces torque some amount (by pulling timing).

acomp917
February 8th, 2010, 04:58 PM
jeocar,

After looking into torque reduction, table is 0 until 148ft.lbs. I don't think I'm making that much torque. When the weather gets better I might zero out the tables and see what happens. I guess the best thing is to start learning all of the pids and how to use them.

S

5.7ute
February 8th, 2010, 05:10 PM
What would be your best bet is to log the spark pids, IE: trans torque reduction spark retard etc to see what is taking the timing.

joecar
February 8th, 2010, 06:53 PM
See GM.EST_XMSN_DMA (and the other Electronic Spark Timing (EST) pids) and GM.TRQENG.

acomp917
February 8th, 2010, 07:01 PM
Thanks for the info,

I'm trying to setup BBL to do that right now. I've got it all done except changing some of the pids to imperial. I posted a Q in BBL section.

S