Hi.can any one tell me whay might be causing my 999 ford expedition to start and then stop when I try to start it. At one point I thought it was my battery, so I had it change. Changing the bettery only made the car work fine for about a week before experiencing the same prablem over again. I also gave my car a tune-up. Can it be that the fuel pump is going bad. Once the car start and the engine stay's on, the car runs fine. the problem is in the morning when I first try to star it. Please help.

Panama,
Is it '99? what size engine? Is it that it cranks then stops cranking, or the engine starts then shuts off?

idle air control motor is bad had that prob also:(