So I have a stock TPI 5.7 in my truck with a 730 running AUJP modified w/Monte's NVSRAM module.

Lately I've noticed when I start the truck in the morning to go to work, or in the afternoon to go home, my idle sounded as if the timing was really retarded.

So I fired up Datamaster (8D) and sure enough for the first 1.5 or so minutes, it idles at anywhere from 4-8 deg advance. After that the advance jumps right up to 20-22 deg where it's set in the main spark advance table and the idle sounds much better.

I've been searching high and low in Tunerpro for a setting that would affect this, but have been unable to find anything.

The tune is pretty much stock, with the exception of changes to the TCC lockup tables to make them more approprate for my 4400lbs 4x4 and 3.42 gears, and I brought the cold idle RPMs down a little lower then stock since it never gets too cold around here. I also made changes to the closed loop timers since I'm running a heated O2 sensor, so it gets into closed loop quicker.

Any suggestions where to look?

Thanks!

 

I think someone else found this a few weeks ago, and $8D uses the 100kPa spark timing at 400 - 800, during cold idle. It's a cat warming feature. Raise those numbers up to the normal idle spark advance, and try again. There's a few temperature thresholds that determine when it does this.

 

Jeremy got it.
I actually think the coolant compensation table does the cat w/u stuff. But Jer knows more about that than most of us.
The 100kpa/208 LV8 column useage removes cold start misfire? based inlet airflow perturbations from affecting the SA and causing even more cold idle issues.
Here's the s/u sa thread.
https://www.thirdgen.org/forums/diy-prom/412181-730-cold-spark-advance.html
You also may want to remove any SA retard from your coolant SA compensation table. It has a 20 degree bias that is used in the calc.
If your table has negative numbers in it already. That means your xdf is using the bias in the display calculation.
So verify your editor doesn't use the bias value when displaying the Coolant comp table and then subtract 20 degrees from what ever your table says to get the true SA/SR. Say your table says 22*. Then it would be 22-20* bias = 2* So 2 degrees is added to all the total of all the other SA's while in that temp range. If it's 18*, then 2* would be subtracted.