Wow... there's a lot to unpack here. Step 1; STOP BUYING NEW STUFF TO ADD TO THE MIX AND TROUBLESHOOT WHAT IS ON THE CAR NOW.
It would help if you told us what year SR20 you swapped in as well. There are differences between the red top, black top, S15, etc..
You've done so much to this car all at the same time. Hard to tell where to begin here. Pretty much everything you messed with will keep the car from running.
If you read the FSM then you already know those compression numbers aren't good.
128 is the BARE minimum with 156 being ideal and max 14psi deviation between cylinders.
The fact that you aren't troubleshooting issues like the fuel pump not running on your harness troubles me. You can't go Kool-Aid man through every wall and just hope everything turns out ok in the end. Did you contact WS about that? If I just spent a bunch of money on a new wiring harness, the fuel pump worked before and it does NOT work now would cause me to stop, contact WS, and get that sorted before proceeding. I'd start there for your fuel pump, assuming I have the facts right.
And, yeah, you need to figure out why you aren't getting spark on cylinder 1. I don't know why you want to attempt to run an engine on 3 cylinders but let me be the first to tell you; Don't!
Hopefully you got the timing chain installed correctly. Here's an article to check your CAS installation and make sure it's aligned correctly;
https://frsport.com/How-To-Set-Crank...gine_t_25.html
https://www.youtube.com/watch?v=sYBHLjY4sRw
As for the injectors, the OEM size for the S13/S14 injectors is 370cc. You've installed 270cc injectors... Those are too small for your application. Might want to try to get the right fuel injectors in there. What was wrong with the ones that came with it if it ran before you took everything apart?
What code are you getting exactly? No ignition signal to ECU will absolutely keep the car from running. I AM going to tell you to read the FSM because the FSM will walk you through troubleshooting all of this stuff. Honestly. EC section. If you've read it multiple times, telling us what portions of the troubleshooting section you performed would be helpful. I'm not going to type this out in my own words when Nissan already did a better job. With pictures.
https://www.nicoclub.com/service-man...14-SR20DET.pdf
I'm guessing you're getting code 21? Have you performed these steps already? This tells you what wires to check for continuity, what you should see when you check them, etc...
