QuestionI have a 93 GMC S-15, 2.8 v6, with 157,000 miles. Sometimes when I shut it down it will not crank. It cranks over, but will not start. Let it set and after a couple of minutes it cranks. Then sometimes it will not crank until the next day. When cold the truck has a slight hesitation like a miss. There are no diagnostic codes.
AnswerI would look at the ignition module.
When you shut an engine down, its temperature actually goes up before it cools off. This is called "heat soak." Electronics will sometimes quit working when they get hot, and the heat soak can make them stop working. After the engine cools off some, or overnight, the electronics will start working again.
If the ignition is okay, there might be a problem with the fuel injection system. The pressure in the system should be checked to confirm proper operation of the fuel pump and fuel pressure regulator. I do not have any data for newer vehicles, but a good repair manual or shop manual would have the pressure requirements listed.
