Cold Idle Tuning Help

[Phillipm]

This is a 2009 LY6 with a stock cam and a set of headers in my 78 Blazer. I'm currently running MAF only and am contemplating tuning the Virtual VE as well. However at the moment I'm trying to get the thing to idle smoothly when cold. As soon as it goes closed loop the idle gets shaky. I can't figure out what I should be logging or where to go from here. There is not a lot of info out there that I've found. I tried to adjust the Closed Loop settings to wait longer but they had no affect. No matter what I do it still jumps into closed loop very quickly. I've tried adjusting the Base Running Airflow vs ECT without much headway.. Any help to smooth out the cold idle would be greatly appreciated.

[schpenxel]

Log idle adapt advance and see what it's doing

Judging by the timing it looks like it's pulling a ton of timing to keep it from idling too high. I wonder if the issue isn't really when it goes into closed loop but rather when the desired idle speed goes down after it's been running a little bit

Idle spark adv is set to 10*. Is that what it was stock?

[mowton]

Do you have cats? If so OEM or Hi-Flow? If Hi-flow or no cats, zero out all the cat lightoff spark tables and see where the idle spark goes to.
Also, as the idle timing seems so low as Carson has stated, check to make sure you don't have a vacuum leak. If not, then reduce the Final Min Air by 10% and see if the timing comes back closer to the commanded 10 degrees.

Ed M