95 Explorer cranks, won't start...for awhile

[exploder girl]

My 1995 Ford Explorer, manual trans. started doing this thing randomly every once and awhile.
When I would try to start it, it would crank, but wouldn't turn over. Then I wait, turn everything off for about 3 minutes, and it almost always would start right up. Magic!

That is up until last week. The waiting for awhile trick stopped working. Now it just cranks and cranks until I start to run the battery dead.

Which I did. So, I got it jumped, then it started. Took it immediately in to get an oil change and got a new fuel filter put in. (a friends recommendation)
It started fine about 4 times, then started doing the cranking but no starting thing again. Waited for about 5 minutes, then it started. Back to its old tricks.

Now today, it has gotten worse. It still cranks but wont start even after long breaks now.
HELP!! I don't even have a bike and have to get to work!

[97exploder]

Had the same thing happen to my 97. Had the crank sensor replaced...$25 part.