Maybe you'll get a specific answer. This one is generic. On many tractors, injector pump timing is done by matching up marks on the crankshaft gear and pump drive gear. It's like timing belts on cars. It's a gross adjustment of getting the right gear teeth meshed rather a fine-tuning. The gears are keyed, so the orientation of the gear on each shaft is guaranteed, and just matching up the marks correctly times the pump. The adjustment may be simple, but substantial tear down is required since the timing gear cover on the front of the engine has to be removed.
On the other hand, the spill time adjustment, which often is associated with pump timing, is a fine adjustment. It is fairly straightforward, but more complex.
It strikes me that pump timing, itself, is simple enough that a dealer's shop manager may be willing to describe it to you. However, you should consider yourself lucky if they'd also describe the spill time adjustment.
