All done guys

in the end

i connected :
Pin 1 : Fat Black w/Blue trace- to be a trigger for a relay (classic toyota 80s relay starter booster) for the starter
Pin 2 : skinnier Black w/Blue trace- to the injectors (constant 12V at ignition)
Pin 3 : Fat Black w/orange trace- to the fat black wire on the body loom side (i dont exactly know what it does !?)

Car runs just fine.

Also, on the same plug body loom side i had :
Reverse lights
Water temp
Check engine light
Oil pressure light

Connected everything how it is meant to be, working fine . runs

Now to fiddle with my RA60 clutch pedal >_< to make it work better.