2000 Monte Carlo SS Problems

Recently my car has begun having a problem where it will stall once or twice every two or so weeks. when it dies it will just shut off not hesitation or sputter just out of the blue it will be dead. after it dies if it sits between 5-25 min. it will run fine for anouther two weeks at which time it will happen again. does anyone have any idea what is wrong with my car?

i took it to my mechanic and the only ideas he could come up with as nothing shows up on the computer is the ignition control module or the crankshaft sensor.

i have a crazy question...but how full is your gas tank when this happens..youre mechanic is on the right path also , just want to rule out a fuel pump issue when it gets hot