8747 Datalogging questions

Hello I'm in the process of figuring out why my truck is throwing fits once it hits closed loop.

1991 k2500 5.7 tbi with a 4 speed manual trans, 8747 ecm with a ARJW BCC, finding the adx and xds files were a pain and thanks to eaglemark I got those, the bin for this set up seems to be unavailable but that's fine since I'm not trying to change anything just pull logs. I have used tunerpro and the apu1 set up in the past for my 89 Camaro using AUJP but that was no advanced work just modifying things off an existing tune, injector size, removing egr and vats..... basically just enough information to be dangerous.

At this point I'm trying to learn more and get serious about tuning and the first step to that for me is going to be able to interpret logs efficiently. Ive been around GM fuel injection for the better part of 10 years and ive always diagnosed without using data streams, that has failed me with this truck so I turned to the dusty old APU1 for help, now it seems ive got more questions than answers.

I hooked up from a dead cold start, connected the laptop and then started recording, I monitored the engine rpm, TPS voltage/percentage simultaneously, O2 voltage, coolant temp and MAP, these sensors being the ones that tie into fueling. The coolant temp sensor tracks normally (I was honestly hoping that would be going nuts or reading totally wrong on me for an easy fix) both tps readings I took track together, engine rpm matched that curve accordingly and O2 was all over the place which from my understanding is how it supposed to be. finally the map sensor tracked with engine rpm.

Nothing stood out to me, my limited experience isn't helping my cause here but I want to know what I should be seeing so I can hopefully identify the problem.

In open loop the truck runs great, rich as expected but great, the second it switches to closed loop I get this insane hesitation, hit the gas and it bogs before rpm gets a chance to go up, if I try to power through it will choke the engine out (and succeed) the mechanical side of this is all good, I just did a full distributor to plug replacement, stabbed the distributor at 0* and all that jazz, set timing to the stock spec of 0* as well, no advancing here. There has to be something I'm over looking here and I was honestly hoping pulling a log would lead to some answers.....not more questions. A week ago the truck ran fine I drove it over 80 miles and had no problems, now closed loop causes it to act up.


So in this jumbled mess of my first post.....tips? tricks? I'm not begging anyone to tell me what the problem is here but I am definitely asking for opinions from people with more experience and hopefully I can get pointed in the right direction for some learning materials.

*EDIT* The engine switches to closed loop on my log at the 4:44 mark, prior to this TPS voltage and map rise track together, closely to rpm rise, once I hit closed loop the tps flatlines for the most part, around 4:53 (just after closed loop) I tried to give it gas and the hesitation happened, map voltage rose, engine rpm dipped way down and tps has zero movement. hopefully a step in the right direction here

I'm not saying that the TPS is your problem, but the gm TPS's are known to get "flat spots" where they don't increase linearly in some portion of their sweep. Put a DVM on the TPS output and run through the full range of motion to see if it is linear.