got an 07 Denali with a 6.2, once and a while it will die, and won't restart for like 20-30 minutes. then like nothing ever happened it will start right back up. no codes at all, even when it won't start. fuel pump runs, has fuel pressure, just won't start. I've heard these things like crank sensors, but will it do things like this? any ideas?

 

I don't know if the Denali's are anything like an f-body but I would suspect a bad ignition relay with those symptoms. Had it happen several times to my car.