92 f-150 spitting & sputtering

friend has 92 f-150 4.9 drove home in ice storm set for day or 2 then wouldn't start,replaced inline fuel filter,which was nasty,rotor button and dist cap,put injector cleaner and gasline antifreeze,finally after 100's of tries it starts,so i guessed fuel line freeze,well when it started it ran for 20 min or so fine,but when u take off and try to accelarate it spits and sputters,put back in neutral seems fine,its like u got to baby the pedal to get up to speed .any ideas?

Have you checked fuel pressure, possible fuel pump failure:smoker2: 92 also had some problems with the fuel pressure regulator:smoker2: