I have a 98 civic sedan with a b18c and type r p73? Ecu I believe.The car wouldn't crank or start so i replaced the starter, battery, ground wires (transmission main battery valve cover cleaned t stat ground).
​​​​​​Checked all fuses cleaned under battery and ignition fuse to be sure also continuity tested them Car started after slightly crimping starter solenoid connection. Ran it one day to test, on the way back the check engine flashed and it shuttered. Flashed again and the car died and had to coast it to the side of the road. Now it cranks only intermittently and the fuel pump is not priming since it shut down. I have a new ebay pgmfi relay in the car now(replaced as part of troubleshooting from before) and the oem one used to prime the pump but it is also not doing anything. Is my ecu shot? Ignition? I have no idea.
There was no check engine prior to it flashing a couple of times before dying.

 

Check your engine wiring harness ground at the thermostat housing... make sure the surface is clean, paint free (don't forget the two bolts that hold the thermostat housing to the block... if you painted the block this needs to be scraped and then the thermostat housing torqued back down) and of course, the bolt is tight on the ground wire.

 

I've cleaned the thermostat ground thoroughly, I will check the housing bolts and maybe even try running a ground wire under the thermostat ground to the chassis, it's confusing how the fuel pump isn't priming all the sudden now.

 

Inside the ecu it is a p73 looks like some corrosion in the middle of pic left of NEC chip or something i'm not a circuit board expert but if anyone knows what these pathways control where the corrosion is or if it even matters. My fear in replacing this is frying another one so i will have to check for shorts before buying another if that's what possibly caused this or it could be just old age idk . Ever since i put it back in radiator fan spins and still no fuel pump

 

Removed radiator fan fuse and now pump primes continuously when turned to run not the usual 2 seconds. What could this mean? Im replacing all fuses since they only cost 6 dollars

 

Well appears I'm gonna have to fix this myself as I don't know any honda electrical gurus around me. I'll update once I've found the issue.

 

Your problem is a good one... I would be looking at a damaged fuse box or burned wiring in/out of the fuse box.