I have a stumble which follows sharp throttle transitions or engine load change that I'm not entirely positive how to start tuning out. My initial guess was that I need to adjust the MAP RoC enrichment and the MAP Decay Time here, since it goes way rich, then lean for a while, then overcompensates rich before finally leveling out. The decay time is 140ms, which seems to mostly line up with the tenth-or-two second rich spot. But the lean spot corresponds with the torque converter flashing to stall speed, then when the engine goes from essentially unloaded to loaded. The same thing happens with the 1-2 shift, albeit less pronounced. There's minimal MAP change and no MAP RoC to speak of in those two points and there's about a 1500 RPM difference between the two (stall is almost exactly 2K, shift drops from 5200 to ~3500 on this graph), so I'm not clear exactly what identifies that situation. The Base Fuel Table is pretty smooth there and Target AFR is constant; seems weird to add essentially a big lump in the Base Fuel Table, especially when the 1-2 shift RPM is lean (14.5 measured, 12.6 target), but the same RPM and MAP are almost right on Target AFR when it passes through in first (12.4 measured).

This is an HP EFI system with a TBI on a big block. I guess the distance from the injectors to the cylinders and then WBO2 sensor (about 6" back from the collector on equal length long-tube headers) are, I presume, the reason the AFR measurement lags the event triggering an AFR change by a little bit. It might help if I knew what a properly-tuned engine in this scenario generally should look like, if there is such a thing. Or maybe not. I'm pretty sure this is not it, either way.

Anyway, here are a couple of pictures (zoomed and not) using the system datalog triggered by 75% TPS. Thanks for whatever pointers might be useful to get me on the right path; I've searched around some and keep coming up empty.
Click image for larger version. 

Name:	2020-06-28 WOT 1-2 zoomed first 0.75 sec.jpg 
Views:	23 
Size:	18.4 KB 
ID:	10046 Click image for larger version. 

Name:	2020-06-28 WOT 1-2.jpg 
Views:	15 
Size:	19.0 KB 
ID:	10047