i have a avalanche 2003 z71 1500, all stock, it runs real good, until the real hot days that i need to have the AC on for a period of time! then it will just shut off, at idle and when im driving! then i will have to pull over turn key to off, then it starts back up, runs for a few mins, then shut off again! doesnt run rough, temp is in range as well as voltage, oil press.! in between the real hot days, it runs fine! no problems! hoping someone can point me in the right direction! thanks!