rileybuildsaciv

I have been working on a b18b1 (non vtec) swap for my 91 civic standard model. I have the engine harness from the b18b1, and it was for an automatic obd2b ecu. I also found an obd2a manual ecu (p75 a02) to use for my swap. I am lost when it comes to wiring the new engine to work.

I found guides on the MPFI conversion that I'll have to do, and they make sense, except I won't be using a resistor box because of the newer injectors.

I think I'll have to find a jumper harness or make my own to match the ECU pinouts, and wire the obd2 specific sensors directly to the obd2 ecu.

From what I've seen, most people use the original civic harness, and splice the connectors on from the integra engine harness. How do I correctly do this since I don't know where to find good wiring diagrams. This is the part that I'm stuck on.

DaX

iTrader: (1)

If wiring isn't really your thing, you may be better off paying for a custom plug-and-play harness. There are many places out there now that build them.

If you do go about building your own, I find it useful to go to a junk yard and pull an extra harness or two...this way you have options to replace crumbling connectors and wires with heat-baked / cracking insulation. The 'newest' EF is still 27 years old! Learn how to depin connectors on the harness, and connectors at the ECU. Get a good soldering iron and some heat shrink for splicing in connectors. I recommend using shielded wire for the CYP sensor wiring and the O2 signal wiring if you have to replace it.

You aren't the first one to do this swap, so I'm sure there's some info out there. Try googling "pinouts for an OBD2a ECU" and then google or search this site for "Civic STD wiring diagrams". I do recommend double checking your specific car against the wiring diagram you find, however, since someone who previously owned it may have changed some things, or there may be slight differences between your specific car and the diagram you find (CA vs. 49-state, 88-89 vs 90-91, CRX vs Civic Hatchback, etc.). If there are differences between your car and the diagrams, mark up the diagram / make your own that is correct. From this point you know how your car is wired and you know how it needs to be wired.

crx_si-r

its easy to wire up your car to run an obd2 ecu. i have my car wired up to a P73 (97 ITR) ecu right now. made my own ecu jumper since im already obd1. i plan to run the type r ecu when i swap in my

SpaceShuttle

rileybuildsaciv

Just an update.

I ended up getting a rywire harness, so I am running OBD1. The install was pretty easy. I would have rather bought a harness from CJ's wiring, but after contacting him he had a pretty long wait time.

Before buying a harness I spent a bit of time trying to figure out what wires on the connectors went to the ECU. Even with the diagrams on the internet I thought I didn't have enough information to splice obd2 connectors onto my original harness. I did figure out how to add MPFI and convert the distributor wiring, but I guess I lost willpower at that point. I gave up and took the easy way out. Now that I've seen a harness made for an engine swap, I think I have a better idea on how to approach another project like this. I will have to learn wiring if I want to do more projects like this.

crx_si-r

Glad your good to go. Yea rywire only does obd1 and they make you have to purchase an obd1 to obd2 ecu jumper to run obd2 ecus.