Today I drove from houston tx to austin tx and i stopped at about 100 miles into the drive to take pics of a trailer i wanted to buy. I wasnt even stopped for 5 min and when i went to drive off the lot the truck turned off and Turned on again but turned off in a few seconds. I changed the coil and the truck turned on and got home. It had happed before and the coil seemed to get hot. what causes this.