Ok so I recently did a swap into my 88 sedan DX. Originally had a D15B2 DPFI OBD0 motor in it. Swapped in a D15B7 MPFI OBD1 motor. I used a boomslang conversion harness.

Car started and ran first try! Only snag was the temp sensor on the D15B2 is on the back of the block with two seperate wires and female pins on them.
The conversion instructions didn't mention it so my buddy and I figured screw it see if it runs. It did in limp mode. So did more research discovered temp sensor on the B7 is on the thermo housing, stole the plug off the OBD1 harness, wired it accordingly, the OBD0 had Black & yellow/green. I wired the OBD1 plug Black to Black and green to yellow/green. Left the negative terminal off the battery over night to reset ecu. No change. The temp gauge does work. I am stumped at this point and its the ONLY cel its throwing.