air in fuel?

[layne]

hello everyone, newbie to the site and the isx, so excuse my ignorance. so,we bought a 2012 kw w/isx15. 500hp. every morning and after being shut off for any length of time, within the first couple miles , it hesitates,shudders a bit then nothing . after a second or two it catches and away we go.after a while it goes away unless i shut it off. no external fuel leaks.new filters.also, even on a good day, it doesn't pull like it should. what's next on the check list? thank you:angel: