I have a completely stock '95 Miata with the mid-year ECU and wiring change. I'm trying to put an MS3x into it, but all the ECU pinout diagrams and basemaps I've found are for 94/95, which I think is for the early '95s. The later '95s use ECU part number BPL9 18 881B, which is set up for the 3 wire coil packs and gets its tach signal from the cam angle sensor. My understanding is that it's similar to a 96/97 except without the OBD II and second O2 sensor.

Is the ECU pinout the same? I don't want to start soldering until I know for sure. Would a 94/95 basemap work for me? Or one for a 96/97? Does any of this matter to the MS3x, or can I just switch things around with software?

 

It looks like the '94 wiring should work, with the addition of a few resistors:
https://www.miataturbo.net/megasquir...rd-tach-44954/

Although I'm still not sure. That thread has a few dead links.

 

I got this email reply from DIY AutoTune:
"The pinout is almost identical with the exception of about 2 or 3 pins - the only one that typically affects a MegaSquirt install is that you'll need to have the ECU provide a tach output signal (such as from the MS3X tach output). The 1.8s are close enough that you can run a '94 through a '97 on the same map, so that is not a major difference."

 

Ever figure out the exact "2 or 3" pics that are wrong?

 

No, I've kinda stalled out on the MegaSquirt since I've been spending a lot of time on my Toyota MR2 project car. I'll post updates here when I get it soldered together and running.