My brain is scrambled over this. I swaped A jdm d15b into a 90 hatch, converted to obd1 p28, with all hasport wirering. Every wire, sensor,ground, and harness has been replaced and triple checked, to include new distributor msd coil, cap, and rotor.The only thing Ihave narrowed it down to is the main engine harness. Any ideas please help. If need be I have a complete headfrom a a d16z6 if need be. Oh and yes the engine is getting fuel, it has a new pressur reg, and a vtec controller that came with car.

 

What finding narrowed the problem to the main engine wire harness? Might the problem instead be a loose distributor connector, a loose wire at the coil, or a bad igniter unit in the distributor?