Engine Clicking And Tapping Noises problems of the 2009 Ford F-150

While driving 60 mph, I left off the accelerator to slow down to 45 mph the posted speed limit ahead. At 45 mph, I slightly touched the accelerator to maintain the 45 mph speed limit, the rpm's went over 4000 and would not stop. I applied the brake, but the engine kept the rpm's between 4000 and 4200. I stomped on the brake with both feet and the un-intended acceleration stayed at the higher rpm. I could hear the anti-lock brakes engage to help slow the truck down, but the engine labored over 4000 rpm. I was concerned with not being able to stop the truck, so I shifted the transmission into neutral and coasted to the berm of the road with the engine staying at a very high rpm. Once I came to a complete stop, I shifted the truck into park and the rpm's were over 6000. I immediately shut off the engine and waited a few seconds before trying to re-start the truck. I checked the condition of the floor mat ASAP to verify it was not on top of the accelerator. This happened to my wife less than a year ago and nothing was found at the Ford dealership and the ogc reviews suggested that the floor mat may have caused the first un-intended acceleration. As I turned the key, the engine would not start and it made a clicking noise. I got out of the truck and opened the hood to check the motor. I could not see anything, so I went back into the cab and started the truck. It started, but would not idle, the rpm's went to over 6000 and stayed constant. I shut the truck off again and waited a few seconds and on the third attempt, I shut the truck back off, because the rpm's would not idle and went to 6000 and stayed there. I adjusted the power adjustable foot pedals and waited a few seconds and the truck started and idled at normal rpm's. I left the truck at the dealership on 7/31/13 for an inspection.