Well I've searched for something similar to this but found nothing, so here goes:

I just swapped a B18C into my 90 STD and converted to OBD-1 in the process using Rywire components (OBD-1 TD44 dizzy, ECU harness, and a chipped P06 ECU since they were all out of P28's). I did the swap and the OBD conversion at my workplace and after it was all ready I began driving home. No CEL's, no smoke, made power, no leaks, basically drove perfectly. I got about 10 miles from work when I noticed my oil pressure light came on so I turned off the car and pulled over. I popped the hood and made sure the oil pressure switch was still plugged in (and it was) and I checked my oil level and it was fine. I closed the hood and tried starting the car again and the CEL came on and stayed on. I had the car towed home and it hasn't started since.

It ran perfectly at work and I had no CEL's when I was driving it, then out of the blue the oil pressure light came on and now it won't start again. It cranks fine it just won't fire. I'm not running an O2 sensor since I'm still waiting for one from Rywire and I'm also still running OBD-0 injectors. The battery has plenty of life and I'm going to check tomorrow if the fuel pump is getting power, if the dizzy is working and making spark, and make sure all my plugs are connected and all my grounds/wiring are fine. Also the main relay doesn't feel like it's "clicking" when I turn the key on and like I said before the CEL on the cluster just stays on. I'm hoping it's just a bad ECU that I can swap out instead of being something else.

Any info/input is greatly appreciated