No start (no spark)

1991 3.1 L V6 GM engine (Chevy Lumina, Pontiac GrandAm, Olds Cutlass, Buick Skylark)

I tried to start my car Saturday but it didn't start. Had fuel and everything but no spark so I said OK, maybe the ICM went bad. The next day, I tried to start the car again and it started right away! Well, I said, maybe the 'no start' problem occured because of the moisture (it rained a lot the day before and it was humid). I drove the car for, like, 100 miles and it died while driving but I was able to start it immediately. I got back home safe and I thought that the nightmare is over. I was wrong! This morning, same problem! Had fuel, had air but no spark. This is what I did:

- I removed the crankshaft position sensor and checked it. It was intact and the readings were according to the specifications. (I used a digital ohmmeter). However, because I had a spare one in the trunk, I put the new one.
- I checked the wires between the sensor and the module and they were fine. I also checked the connector
- I checked for 12V at the module and for proper ground and it was fine
- I checked for the 5V ref from the ECM at the module and it was fine

So, what's next? The module? Is it possible for the module to fail both when the engine is cold or hot? I had this problem in the past and I replaced the module with one from the junk yard. Am I going through the same thing again? Anyway, this time I'm gonna go for a new one. However, if you guys have any tips, I would appreciate your help! Thanks!