Do you mean when you say "it won't crank" that it does absolutely nothing?

If the things above don't seem to be the problem (hopefully you can gather some sort of intuition before actually replacing each) you might check the relays, especially the one for the injection computer (try swapping a known-to-work one in from a friend's car if you can).

Otherwise yes, a good way to tell what's up is with guages. Try to get a fuel pres. guage and start there