I'm in the (slow) process of piecing together parts to swap an OBD1 GSR motor in my '91 CRX. My CRX was originally a DX (DPFI) but converted to MPFI for a ZC swap a number of years ago. Though the car ran fine, I did not do the conversion and therefore cannot fully trust it. I have an OBD0 MPFI engine harness that I'm converting to run the OBD1 gsr. My question is will the cabin harness be compatible?

I've read that there are some connections in the shock tower that just aren't there on a DPFI car compared with an MPFI one (2 extra injector wires come to mind). Do I need to source an OBD0 MPFI cabin harness as well for this swap? Can the DX harness be easily modified to work? Lastly, is there any easy way to tell the difference between a DPFI cabin harness vs. an MPFI one? I want to know how to identify one that I haven't removed myself in case I buy it off someone.

Any help would be appreciated. Thanks.

 

You use the dpfi engine harness. And add the extra wires you need that's it. Don't use the gsr engine harness it will not work. Just take the plugs you need from the gsr harness like the knock sensor vtec soleoid plug and vtec oil pressure plug and iab plug. Doing the whole underdash mpfi harness is way more work. Then doing wat I said as for the dpfi to mpfi swap hear is a good right up http://hondaswap.com/swap-articles/d...writeup-49557/

 

Thanks for the reply. I'm using an OBD0 MPFI engine harness from an Si, I know to modify that instead of trying to make the gsr engine harness work.

Is there a way to quickly tell if my cabin harness is originally DPFI or MPFI, or coverted to MPFI for that matter, that's the real question i suppose? What is/are the differences between the OBD0 MPFI and DPFI cabin harness?

 

the difference is the wiring to the ecu. If it's DPFI pins a1,3,5,7 will be only yellow and red if mpfi they will be brown red blue yellow.

 

The injector wires and a few distributor wires are different for sure. But honestly it might just be easier to just make what you already got work. Just go over all the previous wiring that was done and if there are butt connectors remove them and solder in everything with heat shrink. If someone already did the work for you just go over it and make sure its right. you will know if something is wrong when you go to start it up.

 

you can use the OBD0 MPFI harness but youll have to re-pin a few wires where it attaches to the body harness, as well as adding the extra wires for the 2 injectors, and the 2 crank sensors for the distributor. then youll have to re-pin your distributor wires as well since youre running OBD1. dont forget about the injector resistor box as well (as long as youre running OBD0 injectors)