I started having issues with my EcoBoost going from park to drive somewhere between 3,500 and 4,000 miles. I had the car into the dealership numerous times telling them what was going on and had them check it. Nothing was ever found until I hit a little over 10,000 miles. I had stopped at a stop light and when the light turned green I put my foot on the gas and the car wouldn't go until all of a sudden it kicked in. It did this all the way home. I called the dealership and got the car in and it finally threw a code 4, I believe the tech said. They found that the main pressure regulator valve was damaged and sticking. They replaced the main control valve with new. Had this happened to me when I was passing a car, I could have possibly been killed or caused a terrible accident. If this is happening to your car make sure that you have it checked, as it could be very dangerous. Since the part has been replaced it runs great! I love the car, but certainly didn't expect anything like this so soon. I never had any problems with my 2105 EcoBoost.