Continuity tested all the pins for the following to the ECU plugs, all were continuous and pinned correctly (I haven't taken anything out of the engine harness, only wiring change has been cutting the wires for the 99 coil packs and splicing in those from the NB2):
cam sensor
crank sensor
fuel injectors
coil packs
IAT sensor
coolant sensor
knock sensor

Took it all off the car to do from the comfort of my living room, so haven't re-installed yet (not that I expect anything to change when I do since I haven't done anything).

 

Reinstalled harness today. Ground powdercoat off 2 sides of a tube and drilled a hole through for a bolt for the dipstick ground, which I replaced with a big ground cable (4 or 2ga, can't remember). I also linked this ground to the 2 junction grounds with 10ga wires and ring terminals, and linked the other 2 grounds with another section of 10ga. I also ran a 10ga from the pass side ground junction to the intake manifold. Verified the 2 grounds near throttle body are properly secured. Put in the key, turn it, and still only turning over with no spark or fuel. Nothing registering for RPMs on Tuner Studio nor showing up on a composite or trigger or tooth log. Coolant and TPS do register in TS.

 

Hang in there man, it's always some stupid little insignificant thing causing the problem. I've cut down several wiring harnesses and always had issues afterwards that I eventually figured out.

It's probably not your issue, but I had one miata I deleted a lot of wiring from that would run fine in neutral, but died immediately when I shifted into gear. Are you cranking the car in gear? If so, maybe throw it in neutral and see what happens? That issue ended up being a ground wire I'd cut out, it took me forever to find it.

I'm sure it's one in a million that you have the same issue. Wish I could offer more constructive advise, but I felt like I had to throw it out there. Best of luck to you.

 

After talking w/ Peter Florance (not sure if he is on here?), he said to crank for 20sec to get a composite log. So I tried that, but actually failed to click start on the log as I was watching the clock. So I tried again, and after about 5s of cranking it fired up! Not sure what the deal was, fuel pump had fully primed multiple times prior to yesterday, but it then fired again after a couple rotations, so I will take it. Decided to stop there last night, now have a laundry list of other things to finish on the car, hoping to have it driveable this weekend so I can do a little street tuning and maybe get dome dyno time scheduled.

Thanks everyone for the help, and to anyone who may read this in the future, try letting it crank longer. 20s seems like a *long* time.

 

Checked your fuses? Seems stupid but you never know right? good luck