rusefi.com

What year is your Miata? as reported by Miata Club FB group


https://www.facebook.com/groups/Clubmiata/10155064172440500/

1990-1995: pretty much same ECU pinout (?)
1998: No Miata production, switch between NA & NB (?)

This faq shows differences per model year:
http://www.miata.net/faq/miatachanges.html

And says:

The 1998 was not produced. The 1997 extended late, and the 1999 was introduced early to fill the 1998 production year.