ok my 1994 LS all of a sudden started having some problems.when i start my car it idles fine with the clutch in but as soon as i let out the clutch it dies when in nuetral.and when i take off around 2.5-4 thousand rpms it starts to buck and then will die.when it starts to buck if i press in the clutch real fast i can sometimes catch it before it dies and can keep it running.if i floor it at high rpms it doesnt usually buck.i changed the plugs and wires but i dont know what to do next.any help would be appreciated.thanks.