everything i found in search was for the dx and other dpfi models with the conversions and all this wiring and yada yada. not what i am looking for. i am going to put the z6 motor into my 89 civic si. i have the whole car for parts, so that means i have the wiring, ecu, literally everything i need for this. my question is, how do i use the p28 ecu to run the motor. i thought i could use that ecu and the engine harness to use the obdI setup. looking at the pin out diagrams for the a6 ecu and the p28, they are nothing alike and i really doubt the plugs would match up. so how can i put this computer into my 89 to run the motor? i really don't want to wire in the vtec controller and activator and use the si distributor and all that stuff - i want direct bolt up with as little hassle as possible. if that is an option. any help would be greatly appreciated.

 

bump

 

If you've got the pinouts for both wiring harnesses use most of the d16z6 harness and some of the plugs from your a6 harness.

 

but that's the problem. the pinouts on both computers are totally different. i think there are only two or three pins out of each computer that is the same. so i won't be able to plug in the a6 harness into the p28 ecu. anyone who has done this swap, and info on what you did for the engine harness and ecu? i'd rather go with the obdI than stay obd0 if i can.

 

https://honda-tech.com/zerothread?id=713517

Read my post. It applies to your engine as well.

 

so now i am still confused - i need to get the obd0-1 conversion. after i get that, i see how it would plug into the p28 ecu, but it then has two big plugs instead of the three for the ecu. which wiring harness to i use now? i'm really really confused. i know i am being really retarded about this whole thing, but i just don't get it. i plan on doing this swap in hopefully just one day when i put the motor into the car. it is my daily driver too, so i am trying not to run into any problems with this. i know it has been done over and over so i know it's possible. i just need someone to tell me for sure how to do this wiring stuff. the directions that come with the conversion harness, what does it tell me? will that tell me everything else i am gonna need to know about hooking this up?

 

You use your own wiring harness the one currently in your car and since you are already mpfi you only have to wire up the dizzy with matching the colors from your current dizzy to the obd1 dizzy. You can get a obd0-obd1 harness for $125 from boomslang at the Sponsors Marketplace. The obd0-obd1 harness is used to connect the p28 to the current harness were the ecu plugs are. Hope I make sence but keep on reading and searching.

 

but if i use my original wiring harness from the si, then what about all the vtec plugs and the 4 wire o2 sensor. i wouldn't have plugs for that in my si harness, but they would be in the harness for the motor that is going in. and i was also under the impression that the injectors couldn't run on the obd0 harness cause the plugs were different. would i have to swap the injectors from the si motor to the z6 motor?

 

u will have to obtain the plugs from some other harness... normally get it from the motor u getting it... get the oil press plug, the vtec and others..
if not, be a mechanic and rig it with terminals

 

i just did the conversion on an std, its pretty much the same except for the dpfi -> mpfi. the harness you will be using is the obd0 engine harness. most of the plugs will plug right in, exceptions are the distributor plug, backup switch on tranny, two wire plug next to the distributor, thermo switch, vtec pressure plug, and the vtec solenoid plug which you will have to grab from an obd1 harness (i'm not sure if you will need the injector plugs or not) you will also have to grab an obd0 -> obd1 ecu harness jumper (i got mines from blown90hatch) i wired my distributor plugs, vtec pressure, vtec solenoid, and 4 wire 02 sensor straight from the jumper harness.