droptestls400

so i have a ls 400 1991...started sputtering as if im out of gas..but im not..i hear maybe the fueel filter..this i could change on my own...fuel pump, maybe too expensive this week..need to get it rolling quick..when it DOES keep started, it runs rough , and a weird sputtering cycle..any ideas? email me if so....thanks...cody southpaw@droptest.org