So i just finished up helping my friend with his swap and go to attempt to start the car with an obd1 -> obd2 harness and an obd1 ecu. It wont start, we narrowed it down to the motor not getting spark. The car is a 96 hatch, the harness is out of a 99 Si, the engine/car is completely wired 0bd2. The strange thing is that the motor gets spark and starts up using an obd2 p2t ecu, but if I plug in the obd2 -> obd1 conversion harness along with an chipped p28 ecu, the car gets absolutely no spark. The stranger thing is that the engine, engine harness, obd2-obd1 conversion harness, and ecu were all working perfectly together last month in a different car. The engine was actually tuned on that p28 ecu (Neptune). So far what we figured out was that the p28 ecu, p2t (99si ecu), p06 (another obd1 ecu we tried starting the car on), obd2->obd1 coversion harness, and distributor all work perfectly. Everything was tested in other cars and we had no issues. The thing that baffles me the most is that the exact full swap just worked perfectly in a different car, all we switched over was the shell of the car basically. Everything mechanically and electronically was just tranferred over to another car and now no spark out of a working p28 ecu, but spark out of the obd2 p2t ecu???? Oh and by the way, all of the grounds are fine. It makes no sence to me, hopefully someone on here has an idea of what it would be.