[Av8tor]

Just curious if anyone on here can tell me what all would be involved in swaping the factory efi from a 93 2.3l dual plug motor into 1981 mustang with just the regular 2.3. Ive found a harness and ecu for it, so may go this route for now instead of diving into a MS system. But im curious what all is involved in swapping in the harness and ecu, if its as simple as laying the harness in the car, or if there are going to have to be alot of wiring modifications and splices. If someone could give me some help on this it would be amazing. Ive never been too big into efi so this is all new to me. Id just rather do this then swap the head from an older one onto this motor to stick with a carb.

[OHC230]

OK…. wow where to begin. Well most of what you have to deal with is under the hood wiring, which if you pulled the entire 93' harness form the ECU forward, should be pretty logical. A lot of mechanics I know, myself included, start with the ECU and work forward from there when routing wires. Placing the ECU at or near its final position is a good first step. Feeding the harness through the firewall from the engine side and securing it under the dash would be a logical next step. From there you might want to move under the hood and spread the harness out over the engine bay. Each plug should find a home next. Some will be more obvious than others. It is likely that you will have to re-route some wires as you move along. Don’t worry about the existing wiring just leave it in place for now. When you complete these steps, re-post and I will try to walk you through the next part. Do you have a wiring diagram or do you need one?

[Av8tor]

Well I was more trying to guage if its worth my time swapping to efi right now. I was looking at picking up a harness and ecu off ebay as the motor has the sensors and engine harness still on it. Would you say this is a easier swap then to swap the dual plug head over and go to a carb? I should have a wiring diagram though somewheres around here. Will this swap be complicated at all by the fact that it would still be using the auto from the 81?

[Av8tor]

Well im commiting to swapping the 81 over to efi. I just bought a complete engine harness i found on ebay for a 1993 mustang dual plug car. So once it gets here ill probably be picking your brain a little. What im going to try and have done by the time it gets here is swapping the motor itself out so that the dual plug motor is in the car and the engine bay is clean and ready for the harness. Then when the harness gets here ill work on laying it in and locating where the ecu will be going. Then once its all layed in im sure i will be needing to pick your mind about what else is involved with the swap. Im guessing there is at least a little bit of wiring that needs to be spliced into the 81's wiring. Thanks for all your help though, your a pretty amazing resource on this site so far.

[Av8tor]

So the harness for the vehicle is on its way, and the motor is getting ready to be swapped in. Does anyone know if the ecu from a 1990 4cyl will work on the 93 motor? The ecu is out of a 5spd car and this car will, at least for now, be retaining the original auto trans.