Last trip out....2006 200HPDI...seldom ever run "wide open" anymore...keep it around 50-55mph but decided to open it up and the engine would "miss or hesitate" at WOT like it had water in the gas; ....drop it back down to where I normally run it and everything was fine...I change plugs yearly along with changing the VST filter and cartridge filter in the bilge....except this year I buggered up the head on one of the little screws on the VST and couldn't get to the VST filter to change it...the two fuel pumps on the side of the engine are new...could it be the VST filter can't keep up with the increase fuel demand at WOT or maybe an electrical issue ? Thanks in advance