FIRST.... Um...... Throw the power now valvs away and slap yourself for buying them. They provide the same performance enhancements of a boost bottle...NOT A DAMN THING...I see you're fairly new here so I won't bash on you too hard.
IS the TORS removed or still connected???? That's what it sounds like. Check the air screws..Should be 1.5-2 turns out from bottom, make sure the carbs are sync'd, clean the carbs and filter, etc...Yes the Vito's needles can be the cause.