2001 Pontiac Grand Am

I have a 2001 Pontiac Grand Am, 73,000 miles, that hesitates when I try to start it, if it has 3/4 tank of gas or less and it's parked on an incline. When it won't start I have to put it in neutral and let it roll on to a flat surface for it to start. I've taken it to the dealership twice and even had the fuel tank taken apart and checked and nothing wrong was found. I'm so frustrated! I have 2000 miles left on my extended warranty and I know something is wrong with my car! Any advice you can give is greatly appreciated. Thank you!
May 8, 2006.

Humm, have you ever changed the fuel filter or had the gas line blown out? Any dealer should be able to fix a gravity problem. I would take it back and ask for the service manager and explain the problem. Ask to speak to the area representative.

Keep enough pressure on them and it should be fixed. All they have to do is jack up one end and duplicate the problem

May 8, 2006.