Hi, Ben

as your injectors and odometer wiring are accessible, may be it would be simpler to take the infos at the very source ...

I remember Elektor magazine committed such a project ( in analog mode ...) 10 or 15 years ago ... If you want, I dig into my old papers ...

I crossed it some weeks ago ...

Alain

PS: from circuit cellar source, It would be much better to re-build the project from the C files downloaded ...ohhhhh, yeah , here it's PbP World ... sorry !!!