lookin for help

got a 90 hatch, 1.5l 5sp

this summer the motor would start surging after i drove it for a long time
sometimes when i came to a stop it would stal, it actually blew the ECU fuse!!! if i kept the revs up HIGH till i got somewhere to park it i would at least make it home
computer flashed for o2 sensor and/or injectors

i had a garage check it out they said possibly the computer was fried!!

looked on this place for some answers, looked like could be main relay,o2 sensor or even a cracked rotor
changed the cap/rotor, o2 sensor, main relay

could this be an injector problem?? it hasn't blown the fuse or staled since i changed the main relay
but still surges ALL THE TIME

CAN ANYONE HELP ME??