Mechanic or whoever else is doing the timing needs to have clears instruction on how to do it. He needs to refer to WSM (Work Shop Manual) or some other maintenance manual to follow the instruction. Normally, crankshaft pulley is marked for injector pump timing same as say" ignition timing". Obviously in diesel there is no electrical ignition like gas engine. The injector has to be moved (adjusted ), injector line to the injector opened, position on pulley is checked against when the fuel is squirted out to properly timed #1 cylinder injector. This will happen during suction stage of a carnot cycle ( suck, squeeze, bang and blow).
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