i got an ls an wen im drivin an i stop it sounds like it wants to turn off like its choking or something an then 3 seconds later it does an wen i turn it on if i dun rev it it turns off so i have to keep the pedal pushed all the time cause if i let it go it turns off its gettin me kinda mad now an i dun kno wat it is at first i thought it was the gas buh the tanks full so wat kan it be?