Truck Repair: how to get my truck started, mack truck, fuel filters

Question
I have a 1981 mack truck that been sitting up for 3 years how do i get started?
i have put perussre in the tank

Answer
The steps I would take are.
Change all filters; and fill the fuel filters with fresh fuel before installing them.
Make sure the fuel shutoff arm on the pump is all the way foward (fuel on position)
If the fuel in the tank in not fresh; replace it.
Loosen #1, and 2 fuel lines and crank the engine until fuel comes out of the lines.(if you have problems at this point put pressure to the tank)  Tighten the lines back up, and it should fire with a little cranking.  After it fires and there is oil pressure you want to keep the throttle around 3/4 to WOT for a minute to make sure all the air is out of the system. Hope this helps.