99 ek hatch...Having problems in low rpm. When i push on the gas to cruise or go slow i should say, my car sputers and jerks, but then gets going. Its like have to give it more gas than i should for the car to run smoothly. I dont know how to explain it. I think it has something to do with my fuel, but i dont know. any suggestions...?????

motor set up:

b18a Ls
hasport poly mounts
ported n polished head
gude head package: springs, retainers, valves, cams, n ecu
aem cam gears
polished ls crank
forged 11.1 je pistons
je piston rings
ls connecting rods
msd 6al ignition
msd 8.5 mm pug wires
denso iridium plugs
b16 tranny w/ queffe LSD