when engine check light comes on, vehicles will run good til shut off then it on 2003 Dodge Ram 3500

won't start again...what is the problem? As long as you don't turn off key it still runs great.

Asked by for the 2003 Dodge Ram 3500
it is a v-8 gas engine and vehicle is equipped with full handicapped lift...every time it is shut off it has to be towed and problem is never has been on two code machines but have not been given codes...
you must start by getting codes so we can have a starting point to adv you. when it doesn't start, does it not crank or does it crank and not start?
v8 ...gas engine....cranks but won't start until you leave it sit for about 6 hours then it will start