95 pontiac grand prix with a 3.1 v6.

the car always starts cold and runs all day just fine. the problem arises after the car warms up and you turn it off for 20-60 minutes then the car will either start and idle very rough without enough power to drive (requiring driver to feather pedal and try to clean it up with high rpms) or the car wont start in which case you have to wait around an hour before the car starts.

To clarify this is not a starting system problem the car cranks fine. I just tested the throttle position sensor it was fine. the car never dies on the road.

Im kinda wondering if injectors could leak while the car is sitting. ive been told its unlikely.

any help is greatly appreciated.