AEM EMS Miata on Protege 92
 

Greetings,

I am building a nice project which is a 1992 Mazda Protege LX with a DOHC BP engine. I finish building the engine with JE piston and Crower Rod and other goodies (GTX3076r :naughty:). My goal is 400 whp on pump gas.

Now it is time for the ECU. I was going to do Megasquirt 3 but I look at the AEM EMS for the Miata 30-1710. I look both ecu pinouts of my car and the Miata and for my surprise they the same with one difference. The only difference is an extra cable that goes from the ecu to the igniter which the Miata got two and the Protege one. The CAS is the same both for the Miata and Protege.

So I am sure that the AEM for the Miata will work in my car. The only doubt that I got is the configuration in the Ignition Phasing. Because my car is single coil my question is what will be the parameters to make it work? Besides to turn off Coil1 because Coil2 is the one that connects to the stock igniter on the Protege.

P.S. I am not a Miata owner but we are related. :bigtu:

Any help will be appreciated.

Regards.

I'm assuming your car runs a distributor based on you saying you have one coil? The reason the Miata has two wires, is because it runs a waste spark system with cyl 1/4 and 2/3 firing on the same coils.

My only real contribution would be to use those two ignition outputs, and wire in some COPS in waste spark. You'll have to run an extra wire into the cabin but that's about it.

I have the 30-1710 AEM in my '92, the car it was designed for. Even still, I have many wires swapped within the harness and many changes to the calibration. I'll bet you will have to do more changes than just unchecking the coil one box. Just doing that will only fire coil 2 once every crank 360deg, assuming the protege distributor or whatever outputs the same CAS signal INTO the ecu. You will have to at least change the tooth counts for coil 2 so it fires every crank 180 deg if you're running a distributor.

Just because the wires on the harness are labeled the same does not mean the sensor calibrations are the same, etc. But getting a driveable tune is pretty simple if you know basic things. AEM's EFI manual is very good as well as their aemPRO instructions. Download these .pdf's off their forum and read them a few times thru.

What about getting the new AEM 4?