Check on left of engine at flywheel . Their is a window...the casing has a pointer on. Turn the flywheel till you get to the marks for the injectorpump fitted to the engine. Like if you have a CAV pump then the mark must also be CAV.
Remove the pumpgear and turn the pumpshaft till it locks up at number 1 outlet.
Install the gear without turning the pumpshaft.