Help, my nissan died today!!

i was comin home from work today..... came over the last hill and it struggled a little bit, and as i came home if i let it just idle it would die, so i would start it again and as long as i kept the rev's up it would run... but then die after a while. Now it starts and stumbles for like 3-4 seconds and dies. and now its nothing, lol do you think its my fuel pump? its an 87 nissan ext cab with the Z24 motor. thanks for any help