There is no spark to ignite for combustion.
The compression is so great it heats the air hot enuff that when fuel is supplied it ignites the fuel/air mix. The pump act as the distrbutor and fuel delivery system. If you read in your manual you'll find there is a mark on the pump and one on the top of the timing cover. Line these marks up and it should start. Remember these marks were put there by GM, meaning they are close to being correct. After you get it running you should go to a diesel shop and have the timing checked and adjusted. Timing is critical to a Diesel.
For further info do a "search" on this subject. Remember, your truck should have mechanical injection when do your homework. There's no offset timing.
92 GMC std cab C2500, Kennedy high flow injectors,port matched, Banks exhaust & gauges, intercooler, 97 cooling, Turbo Master.A means for a Toy