When i start up my 1994 firebird formula 350 lt1 it bucks every so often on a cold start then when i drive it every once and a while. what could be the problem? I replased the fuel injectors, fuel rail, and did a tune up. The guy i bought it off of said it needed a new fuel pump cause the amps were to low. please help i really dont wanna sell it, its my baby. pleaase help!!!