This has been going on maybe once a month or so, for the past year. It's certainly not everytime, or only cold, or only hot....nothing consistent. But everynow and then, when I start the truck, it sounds like I have my foot floored on the gas pedal, I mean the thing starts and immediately heads straight to redline....I shut it down, start it again and it's fine....I am 100% sure that my foot has at times not even been in the cab, (most recently I know because I utilized the clutch cancel switch, so I was reaching in the window from outside....)

any ideas?