90 suburan randomly blowing ecm b fuse

my 90 sub. will randomly blow the ecm b fuse, has gone months without a problem, then will start blowing, again. after a few days, will most likely clear up and run again until the next time. seems to come and go on its own. trying to trace wires but not sure where they run. i am thinking that it has to be a sensor, i don't think if it was a dead short, it would be random. i'm tired of playing russian roulette each time i drive it. i need some help on this one

EMC-B fuse feeds the fuel pump relay and oil pressure swith to fuel pump feed.