So i was driving on the freeway at 65ish and all of a sudden the rpms drop to 0 and i slowly decelerate because the gas pedal was doing nothing. It dies when i pull over but then fires right back up. I continued driving around 45ish and sometimes the rpms would drop like 200-300 then shoot back up causing it to sort of jump. I got it to my mechanic to put in a new fuel pump and he said there is a leak in the gas tank. Could this be causing it? Or anyhone know what it might be?