411 cold stumble

[FeetDry]

I have a 411 PCM running on a 2000 4.3L Auto Vortec. I've been tuning the fuel for a few months now, basically trying to learn what does what. I've spent most of my time tweaking the B0101, B5001 tables. A problem that I haven't been able to get rid of is the stumble during the warm up cycle. I'm not sure if it is a fuel or spark problem. It happens worse when the engine is running cold. The colder, the worse it is. It happens at the trans shift points. 2->3 or 3->2 is real bad. The lighter the throttle action the worse it is. Sometimes it will launch you forward out of the dri-seat. (Like the fuel got turned off.)
My guess is that it is the spark control for the trans PWM, (TqMan). Basically power output goes to nothing during shift or PWM/TCC unlock operations. The WBO2 lamda will spike above 1.5. (see image) I've tried to disable any and all TqMan operations, but it has not helped. Basically no effect of the problem.
I've retried the stock cal and noticed the same problem, but it is very mild. (Hardely noticeable.) The better my cal gets, the worse the stumble gets.
I'm thinking this is nothing new for most tuners here. Could you give me some assistance with this?

[FeetDry]

To get rid of the TqMan, I've played w/:
B1902, D0301, D0801, D0802
None of these changes has helped get rid of the cold or hot stumble. The hot stumble is minor compared to the cold. I typically notice the hot stumble when the Lambda alarm (above 1.5) gets triggered. The hot stumble will typically happen during a PWM or TCC action.

[hog]

Stock engine? There are stock 411 and blackbox tunes for the 4.3.

peace
Hog

[FeetDry]

I've run the stock tune. It performs pretty bad.

I think I'm looking for a "coolant temp vs Tq Reduction" table.
If it is there, I am not finding it.