Hey all. So, background: I have a S13 Blacktop SR, pretty much completely stock, has always run like a champ. However, I've had an auto ECU in it since day one, and finally decided to swap it out for a manual ECU to get rid of the annoying rev hang. Yesterday I primed the car (it had been sitting in storage and hadn't been run for a few months) by unplugging the CAS, but the battery needed a jump. Jumped the battery, car started right up, idled perfectly, sounded great, etc etc. I turned it off, swapped the ECU, then went to start it up again and the battery had completely given up.
So, today I went to get a new battery, swapped it out, started it up with the new ECU and could immediately hear (and FEEL) that it was missing a cylinder. Tried swapping coil packs and spark plugs around, problem stayed on cylinder 4. Checked the pins on the ECU plug as well as the ECU itself, they all look fine, the wiring looks fine, I'm at a complete loss here. Also tried the auto ECU from before, no difference.
What could I have possibly fucked up by changing ECUs? Maybe I pulled on the harness too hard? Could it be something else like the ignitor chip? Kicking myself over this, not sure what to try next.
