Have a 1991 RS 3.1L. replaced fuel injectors, fuel filter, distributor cap and rotor, and nothing has helped. My car starts and in the beginning it idles good but after about five minutes it begins to sputter and cuts off. it then starts back up but keeps doing the same thing. i would really appreciate some help. I am a college student working full time so moneys tight, so i'm really trying to budget this fix as best as possible.