EF Wiring�� By Ben Ogle

When you do a motor swap into your EF you are most likely going to have to do some wiring. If you have a DPFI model (dual point fuel injection) you will most definately have to do a DPFI => MPFI conversion, and if you are putting a VTEC motor in there you will have to wire for VTEC. It is a lot easier than it looks or sounds. Throughout all this i am assuming you are staying OBD0.

When wiring please use solder and heat shrink tubing. It makes your wiring last longer and look MUCH cleaner. If you cant solder I think you should put off this wiring job until you can (or get one of your soldering friends to do it).

MPFI: what to do.

You are going to use your stock engine harness as the base of your "hybrid" harness. Not the engine harness that came on the motor, an Si or Hf harness (unless your car is an Si or Hf), or a B18a harness (not even with a B18a). This is a common misconception. People always want to use a stock MPFI harness. The problem is that it doesnt work unless you want to repin the connectors that connect it to the car harness. IMO that would be a lot of work.

The engine harness you got with your motor is going to be used for parts. You need the injector plugs (I cut the wires as far back in the donor harness as I can so I dont have to do any lengthening), the injector resistor plug (dont even cut it off the injector plugs, just trace it back), and the distributor plug. In addition to the plugs off the donor harness you need an injector resistor box. This box can come out of any OBD0 civic or integra.

Now that you have all the stuff lets get to wiring. I like to do all the engine harness stuff first so thats how I'm gonna write it. Keep in mind that this is MUCH easier to do with the motor out of the car.

Engine: ECU plugs:
If you are more the visual type then this is for you. (Big thanks to evilxkid for letting me use this).

VTEC wiring.

If you gotta b16, b18c, or ls/vtec and are running a PR3 or PW0 you have to wire for VTEC. This is VERY easy. The best thing to do, IMO, is to make a new harness just for the VTEC wires. I usually find a 4 or 6 pin male/female plug combo from one of the harnesses that I have and go from there. If you dont have any harnesses floating around then a junkyard will definately have one that you can pull plugs from. In the cars I've wired this plug combo resides on the clip (yes there is even a clip for this plug. They were thinking of us swap guys!) right next to the big white pass side plug. What you do is run the wires from the ECU to one end of the plug (the end that clips onto the clip), then make an engine harness with all the wires converging into the other end of the plug. Heres a pic of that "VTEC plug."
the VTEC plug is the samll one under the big one.

Engine harness. Pic of the VTEC solenoid and the oil pressure switch:
read the red writing, f00

Car harness.
Pin Function
A8 VTEC solenoid
B5 VTEC oil pressure switch
B19 Knocksensor
C8 Second oxygen sensor