since your talking cap and rotor i will assume this is the GM vortec V6?
you might want to check the oil pressure switch also, these will also kill the ignition if the switch is bad. just use a vom, put in ohms and read across the switch, crank the engine and it should close, if not then replace the switch.
most of the time you will see evidence of it leaking as well, sometimes they don't but always check that switch, it only takes a couple minutes and is an easy check and fix.