vacume leak or fuel pump

[dan cocomise]

it fills like a vacume leak it hesitates. but i cant find a vacume leak. fuel lines are tight.1/3 of a tank of gas little hesitation i fill the tank full it can harly run is it the fuel pump.pump is one year old 400 miles on it.thanks

 

[Bill Hanlon]

Unvented tank/cap??? This would tend to be more problematic with a full tank than one that was near empty. Try loosening the gas cap and see if the problem goes away.