Well this was supposed to be a straight forward swap: 1995 Civic DX Special Edition with a tired D15B7 and auto transmission D16Z6 as the replacement motor It's all OBD1, but the Z6 didn't come with a harness, so I swapped the B7's harness over while both motors were out. PROBLEM: The motor cranks but doesn't start. There is spark The fuel pump turns on Fuel comes out of the fuel rail when I disconnect the return line, so I assume I'm getting fuel It seems like the injectors aren't opening and the fuel is going right back through the return line as the spark plugs aren't wet. I've checked all 4. I've checked all three grounds in the engine bay and double checked my connections. It's my understanding that the main relay controls both the fuel pump and injectors, so am I right to rule that out? Anybody have any ideas?