stutering

my car is stutering liek it has very bad gas it has set for a year and i just bought it but i heard soem thign abotu a fuel realay that could make it do the same thing any one got some info on y it might do this. it looses rpms bad while setting but once i get to abotu 3 gs on teh gauge it settles out. im wonderign if it aint an exost leak my self
any help whould be great thank u