It is closest to the radiator for the 4 cylinder engine motor.
Mitsubishi 2.3L 4D55 Turbo
In front of the fuel tank. You will likely have to remove the rear driver side wheel to get to it.
with a floor jack.
Should be right next to the fuel tank underneath the truck bed.
If your 1991 Mitsubishi Mighty Max dies after you start it up it could be one of several issues. There can be issue with the batter, fuel relay, or distributor.
Timing belt replacement on 88 mighty max
Autozone or Advance parts