Wiring diagrams are sensor info is available for most of the vehicles. There are at least two options how to build a map for a vehicle, that's unless this info is already available:
You can start by making an educated guess about the base values (10 degrees BTDC is a common start for timing, and fuel amount directly correlates to engine output/displacement, and injector capacities are also known usually), or you can put the original ECU on a bench, stimulate it with fake signals and record the reactions - that's the way I did it.
If you think you might be interested in playing with all this you should check the
http://rusefi.com/ wiki and
rusefi.com • Index page forum.