VSS, tach, injector signal logic

[wikityler]

I'm in the process of building a carputer for my newly acquired '92 Plymouth Acclaim. I'd like to build an interface to allow the carputer to calculate FE much like the MPGuino. The MPGuino uses the injector lead and VSS signal to calculate the FE. I'd like to also use the tach line for a digital tachometer. So...

What kind of signal logic do these lines use?

[SVOboy]

Don't know, personally, but welcome to ecomodder!

[nowhhs]

Have you thought about taking the trip computer from a different chrysler? I know they had at least 2 different ones, one called a Traveler, and one called a Navigator. They both show instant mpg as well as trip mpg, among other things