I have had my 2000 Taurus, Vulcan engine, since 2001. Ever since I've had it whenever I step down on the accelerator cruising at about 30-35 the engine will rev but there is a delay before the car will actually go. It appears that it is reving up and then it just takes off. My Ford Escape, 3.0 will go as soon as you step down on accelerator. What gives with this ?