whats really going on

[240sxbobbis]

ok my problem i searched and nothing is coming up i finally finished the rebuild on my car started running good everything took it for an test ride and the car ran fine upon acelleratin it will sputter and what not pulled her back in checked cant figure it out. so i took her out again an driven her with the sputter it was there again and then she cut off nothing but i have power rolled her back home and up the drive way switched the igniter packs checked codes nothing incoherient with it switched the packs and gave her a crank same thing wont start what can this be any one dee ?