I had a very similar experience with my 2000 Blazer. It would crank over strong, but wouldn't start. I disconnected / reconnected battery after 15 seconds, and it started right up. I have done this twice now successfully. But now on the way home, it died 3 times. And it did restart each time without disconnecting battery. I suspect this is heat related. Worked fine in the early cool morning. Do you suspect the Ignition Control Module intermittingly failing?

Yes.

Ultimately I determined that it was a faulty fuel pump (parts and labor = $400). When the vehicle wouldn't start, I could bang on the bottom of the fuel tank which somehow freed up the fuel pump to pressure up and allow vehicle to run again. If you want to find out if it is a firing/ignition problem, just disconnect the coil wire, turn engine over and watch for spark.

signing off on this problem,
dbteeitup