Bad idle when closed loop hits

I have a 1995 K1500 suburban (think work truck model) with an automatic transmission, and a 350 SBC TBI.

This was a project car of my fathers, but he got tired of it and has moved on to other projects and gave it to me! He added an MSD ignition box, their blaster module, and put in their distributor (saw a little too much powerblock TV and is retired. why fix what isnt broken amirite?)

Well, the truck sat for 3 years and the truck wouldnt start. I started with a new battery, moved on to a new distributor unit from autozone (the MSD he put in was completely seized up into a solid rod. couldnt even cheat it loose), took out his msd blaster but left the MSD ignition box (this I will have to get the model number for. its a pretty stout box and works completely fine).

Now the truck fires up first time every time, but, once the computer goes into closed loop mode the idle goes to crap. It will drop to 350-400 RPM, surge to 800-1000, return to idle at 700, and repeat every 5-7 seconds. If I put it in gear the truck will just stall. I have attached a datalog from after the truck warmed up. This is with the timing wire under the dash plugged in as well. Even removing the battery I am not able to get rid of that check engine light. I have been referred here by a coworker who is probably best known for his Wagoneer project.

Any questions I will try to answer as promptly as I can. I am kind of thinking it is a bad ignition module, but it shouldnt be, the distributor has 5 miles on it if that. I believe the motor is a jasper rebuild.