My fuel pump not priming on my 1988 b18b swapped ef sedan lx, replaced the fuel pump thinking it was that and it didn’t turn on and I played whit the wired of the fuel pump leveler and the car turned on and ran my car for a couple hours and it wouldn’t turn on any more, then I changed my main relay and tought that was the problem but it wasn’t can it be the ecu? Lmk wat can It can be need this car running.

 

It is very likely the ECU (assuming OBD1 conversion?). My guess is the capacitors have gone bad. Pull the ECU and remove both covers - any fishy odor? Visually inspect all the electrolytic capacitors (they look like little cans - google if you need a pic for reference) for bulging, burst ends, or leaking. When they go bad they can leak electrolyte onto the board and cause bad corrosion which can damage the board - it will look very dark in color, usually. If you're lucky you will find that none of the capacitors are leaking. If that's the case you can replace all the capacitors and continue using the ECU.