91 Miata 1.8 computer/harness swap
 

Hi there!

So this is the deal, I have a 1991 Mazda Miata project build that has come to a grinding halt and I am in need of some assistance to finnish the project. There are a number of things that need to be done before the car can be operational the first of which is a wiring harness conversion. This car is a bit of a mishmash of parts with the intention of having a mix street/autocross/track day car. It is a 91 as stated previously and I am using a 1994 1.8l motor that has been fully race prepped by Dave Rabello in Antioch. The bottom end was refreshed with new 2001 pistons for higher compression and race bearings wile the top was ported and polished with the addition of some larger lift and duration cams as well as adapted to use a 99’ intake manifold. The motor and ECU were then dyno tuned and came in around 178 hp and 165 tq. The Stock 94 computer was used but re-chipped for the modifications. The challenge now is getting that to wire up with the 91 wiring harness that is in my car. I have schematics of both the 91 and 94 harnesses and the conversion looks relatively simple with the addition of 2-3 wires and moving some pins around on the connector (which will physically use the harness without being modified).

I am looking for any guidance you guys might have. If anyone has done something like this before and can give me some tips that would be greatly appreciated.

Otherwise....

If you feel comfortable with doing a conversion like this I am glad to pay well for assistance with getting the car up and running. The next phase will be to swap over all the suspension and break parts from the 94 over to the 91 and I could use some assistance with that as well.

If interested give me an idea of a fair hourly rate or flat rate if your more comfortable with that and also let me know what your experience with cars/miata’s is. Thanks and I look forward to hearing from you soon!




Cheers!
Lucas

Sounds like a pain, have the 91 re chipped or go standalone. Standalone > chipped stock ECU.

I've wondered about that too, my brothers car is a 1.8 swapped 1.6, we used all the FM '1.8 conversion' parts, but it'd be a lot cooler if we could put my 1.8 ecu (I just bought a 94) in the car so I could get my megasquirt out of his car, hehe. I quite a bit of searching but couldn't find where anyone has actually done it, you'd also have to swap the MAF over, and I don't know what that would do for the fuel pump wiring... its probably going to require some time with both wiring diagrams and a bit of luck. If you do manage to make it work, post it up for the rest of us :)

Standalone is definatly an option but I would still need to adapt the wiring harness for the 94' ignition and fuel from what I understand since the connectors are all different. I will post some pics as I get going with this project. Anyone out there who has done something like this or has suggestions to other threads let me know. I have tried looking through stuff on multiple sites and just haven't found the info I am looking for. Thanks for any insights you can provide!


Lucas

91 re chip wasn't an option according to the motor tuner based on my modifications...

If you are asing for help. It would be helpfull to know where you ae at so that someone can possibly come over and help out.

Have a great day,
Jared

Good call! The car is located in Martinez Ca. However, I would be willing to tow it anywhere in a 40 mile radius...