In the morning, it starts right up, no problem. But if the car is already warmed up, like if I go to the store or something, and I return to the car, it has trouble starting -it cranks and cranks for about 5 to 7 seconds then finally starts. Problem seems worse in the summer heat. There's no smell of gas or any other symptons that I've noticed. I have 60 k on the odometer. Any ideas?