The other day I got into my 2000 gmc sonoma and went to take off but the gas pedal was already on the floor. It is as if the pedal is pushed in but it does not accelerate or rev up at all. I can pul it up by hand if I mess with it for about 5 minutes and within a few minutes of driving it the pedal will fall back to the floor. Any suggestions? As you can tell I am no mechanic. Any info would be helpful.