Circling back on your yellow wire. I have an '88, I wouldn't expect much difference in the wiring, but I don't have that wire. Yellow is an odd color to go to ground, but in the factory harness yellow is the power wire to the ignition and the ICM below the coil. You might want to trace that out in the other direction and see where the other ends go.

 

I have a hose that goes from the coolant reservoir all the way around the passenger side fender then across where the hood hooks to the chasis which leads to the radiator. The yellow wire traces this path and I've checked older pictures of the engine bay and I don't think it was ever connected to anything.
I've uploaded a very short vid to YouTube so you can see what it looks like. It's definitely weird. It's a yellow wire that is spliced into a black wire which then grounds on the chasis on the driver side. Maybe a very old accessory or something.

 

I just tried this and nothing. I'll create another post with detailed issues, what I've done, etc.
Thanks for your help.

 

have you tried replacing the part the other user had a link for? I am telling you I had those issues like I described and replaced a lot of stuff as mentioned and nothing work for more than a day until that one part. I believe he also stated its located in the distributor. He said they call it the coil pack sensor. I replaced that in mine and never had a problem since although mine was called the ignition coil pick up sensor. I would try that and see if that alleviates your issues.

 

Yup, I will be giving this a shot next. I found one reasonably priced at OReilly. I haven't been able to find a whole lot of information on it other than a few videos of people taking the distributor apart and yes, it sits towards the bottom of the distributor.
Link to Item for Future Reference
I'll update the thread when I get this replaced. Just overall weird that this specific part would fail... the cables lie on the opposite side I would've touched for the oil change. Maybe the oil change was just a coincidence... Part of me is spiraling lol. Thanks for your help!