Pleez don't let the thread die. I've learned that my new[er] car has OBD1 (or something).
I have some knowledge of analog electrics and digital electronics, but I can't get a crimp-on spade connector to work. ....but I've gotten a butane torch so I can solder things.
edit: to start with: compare and contrast MPGuino and Scangauge. TIA
2nd edit: Okay now I've found
ecomodder.com/forum/opengauge-mpguino-fe-computer.html.
It's like discovering a room in your house you diid't know was there.