My 2001 chevy silverado 4.8 liter V-8 starts great when the engine is cold. only thing noticed is the battery icon appears for about 2 to 3 seconds. After the truck sets for a while and you go to restart it it cranks and cracks then it may start. If not then turn key again or a third time and it starts right up. It reminds me of the old days of carborators and vapor lock. We have done the following with no success, new battery, Bosch platnum spark plugs, fuel pump has plenty of pressure, put GM carbon remover through the intake manifold thinking carbon was absorbing the fuel.