TurboEF9

Well, not all OBD0 distributors are vac advanced.

..but before you could go to "OBD1", you need to swap to MPFI "OBD0". Then, from there, you can make another harness to go to OBD1 if you still wanted to.

..though, it sounds like you wouldn't need to for that far.

I would search Honda-Tech, first, to get the information needed to be a MPFI setup of the 88-91 Civics. Then the pin-out for OBD1 Civic/Integra is in the PGMFI Wiki (http://wiki.pgmfi.org).

robs89lxi

Okay, could not find pinout for Integra/Civic, unless you are refering to the B16A2? That was the only one I could find. Would it be the same for a p75, or maybe a pr4?

TurboEF9

OBD1 -> any Civic/Integra pinout will work.

OBD0 -> Looking for a 1991 Civic Si, PM6 ECU pinout.

robs89lxi

Okay, from what I've seen so far, the PM6 you suggested is a very popular ECU choice, so that is good as far as support goes. Three things though:
1. Will this be okay on a 2.0L engine?
2. Is the 91 CRX Si distributor electronic advance?
3. Do you know how similar OBD0 harnesses are? Can I just swap ECU's, or will there be different sensors/inputs that will need to be modified?
Again, apreciate you patience on this.

omahaturbocivic

Here is all the info you need to build these harnesses.
http://www.pgmfi.org/twiki/bin/view/...KurtsOBD0-OBD1

I have built 3 of these using this guide and every car fired right up with no problems. Just make sure to take your time and double check each connection because its really easy to mix a pin or two around after soldering so many connections.

TurboEF9

robs89lxi

Guys, thanks for all your help. Omahaturbocivic, great link. That will be my bible when I start. By the way, the three cars you've done these in, any Accords? Jason, thanks especially for your patience ! I'll be sure to let you know how it turns out. I appreciate your suggestion on the CRX, and I think I will start out with that for my first try. If it fails, I guess I will go with the OBD1 conversion. Again, thanks a bunch.

biggmike

should make good conversion sites a sticky or put with engine mangagment sticky

omahaturbocivic

No accords yet. I have hardwired one civic std with obd1 clips using this guide and I have also built 2 harnesses for a hf crx and si hatch since then using this guide. I have also used an obd0-1 harness fromhttp://www.jkobdconversionharness.com/ which also worked exactly like the harnesses I built. As stated above your best bet is to find a ecu pinout for your accord and compare it to 91 civic si pinout or the obdo side of the guide I posted. If it all looks pretty much the same you are good to go with either the obd0 pm6 or the obd1 harness as posted. If there are differences you will have to switch the wires in the car or just switch them in the harness if you do convert to obd1. Even if the wiring is a bit different that should be able to be overcome if you are comfortable with wiring and have a good accord pinout.

You biggest issue may be deciding what mpfi distributor will be your best bet to fit on the motor. If you stay obd0 you could possibly use a d16a6 b18a or b16a distributor depending on if any of those can be made to fit your motor, obd1 you can use pretty much whatever distributor you can get to fit best wether that be from a newer accord, civic, integra, whatever. There may not be one that fits exact but by drilling out or cutting some of the legs you can hopefully get something to work. Like stated above you may be adding adding a few wires from the distributor to the ecu you as well as splicing in different clips.

robs89lxi

Hey, great info. Yeah, I've got a pinout diagram for my ol' PJ0, so I'll be doing some comparing. Is the PM6 in the '90 the same as the '91? Just wondered since you guys refer to only the '91. One guy I've seen used a F-22 dizzy ('90-'93 Accord) in his OBD swap, but it did need a bit of modifying to fit. Thanks again for the help.
PS Where can I get a pinout diagram for PM6, PR4 and/or P75?