1994 Mitsubishi Truck will not turn on

Engine problem
1994 Mitsubishi Engine Size unknown Two Wheel Drive Manual 156417 miles

i'm trying to figure out why my truck will not turn on. The other day I ran out of gas, and after refueling, the truck was working fine until I turn off the truck. The next day it would not turn on. I checked the fuel pump, and it is working. I checked the fuel filter and it was a little dirty, but fuel is still being pumped. Will it be that the fuel injectors are plugged up? What do I need to check or what do you suggest I can do? Please let me know. Thank you for your help.

ps. I think it is a four cylinder truck because I only see 4 spark plugs.