I have been doing plenty of research since I got my OBD-1 P72 ecu. That was about 2 months ago, and I still can't get my secondaries to work properly. My civic is a 00(obd2b), motor is a 98 B18c1(obd2a), P72(obd1). Motor is OBD2, which needs a positive trigger right? But the OBD-1 ecu supplies the negative trigger for the IAB. I took the IAB plug from a JDM H22, which has a pink wire and a black wire. I ran the pink wire to a constant 12v source(#1 injector), and the black wire to pin A17 on the ecu. When I turn the car on the run position, the butterflies move up, which means it's closed. I rev it up to around 5500rpm, and the butterflies drop. It seems like it is working, but my car is running like crap when I drive it. The low end sucks, and so does the top end. I could really feel the lag in low rpms, and at high rpms I could see white smoke coming out of my exhaust. I was running an OBD-2 P2t(99-00 SI) ecu, and it runs awesome. But the ecu will not idle, so I will have to use the P72.

 

NO, I'm pretty sure you still need to wire it as OBD-1 since you're using an OBD-1 P72 > the pink wire should go to A17 and the black wire to a ground, preferably the thermostat housing.

 

I just got done checking the voltage with a multimeter. I think I'm getting a constant ground signal from my ecu(A17), and the injector is the constant 12v source. I checked the 2 wires at idle and it shows up 12 volts. The IAB looks closed because it is in the "up" position. So is my ecu suppose to cut off the ground source to the IAB at around 5500??