from actual experience ive had 2 busas doing the same thing, no fuel pump prime and no start sporadically at times. both were ignition switches, and both cured for couple of years now by spraying contact cleaner and wd 40 into the ign switches themselves lol .also have had a couple of gen1 zx10's doing exactley what yours is doing, both were the common ground junction box in the main wiring harness located just next to the harness connector to the fuel pump. one corroded, one burnt. boxes are taped up square in appereance plastic housings that have to be unwrapped, pried open to inspect. bad ground causes a multitude of problems, but was problem both times with same symptoms as ur having. main ground box is connected directley to end of battery negative cable, with multiple system ground wires coming off of it. seriousley doubt ecu bad, first thing is to is get fuel pump/pc powered back up, this could well be problem, it was for me.
Last edited by gaz; 04-21-2018 at 09:18 AM.