zc floods out-- need help

i put a 86-87 zc in my 87 civic si , and for some reason it is now flooding so bad i can't start it and when i finally do get it to turn over (if i do) then it runs extremely rich. i'm using the civ's wiring harness and ecu, i replaced the main relay and a leaking injector. i tested the map sensor (even with a voltage drop on the sensor wire) and it seemed good also tested cyl. pos. sensor, TDC sensor, TPS, injectors, injector relay, fuel pump, fuel pressure, and fuel pressure regulator. i was thinking the o2sensor might be bad but i tested it out of the car and it made voltage plus the problem is when its first started so the o2sensor couldn't cause that. if its running and i finally clear the flood out it still runs rich and has an irratic idle. i am not throwing any codes. i am tired of spending money on parts and have myself and 2 mastertechs/ teachers confused. i'd appreciate any help solving this problem so if you've run into this or similar before or just have any suggestions please reply.