The truck can run on 4. Not good, and you will think something is horribly wrong, but it can run.
There are way too many other things to cause a no start to jump to bad injectors. Simple check list:
Is the oil within full tolerance?
Is there smoke when you crank?
Is the HPOP level w/in 1" of the top?
Can you hear your fuel pump?
Are you below 1/4 tank?
Do you have gauges? if so, more to check
What is the voltage while cranking? If below 10.5, you need a jump.
Are RPM's displaying on your not dash gauge? If not, maybe new CPS. I can't make my '02 not start, and I never checked my CTS RPM gauge when I had a no-start position, but it may show RPM.
What are your IPR and Duty Cycle readings while cranking?
I'm drawing a blank for more, but that should get you started down a good path to figuring it out.