If it has a Bosch Injector Pump, one hole in the face of the Pump Sprocket is Slightly smaller than the others, and a corresponding recess in the face of the pump.
there is a special pin to locate #1, but a wooden dowel may work. Hope this helps.
This is the Denso Mark, cast into the body of the pump. the mark on the pulley is easy to miss, so be careful.
Glad to help.