I'm working on a 1993 Integra hatch with a B18a1 and manual transmission that has an intermittent crank but no start. It went from starting and running fine to taking a few seconds extra to start, then cranking but not starting. Since it was time for a new fuel filter, I replaced that and since I have had pgm-fi relays test well but still fail, I replaced that. The car fired right up after priming the fuel filter. A few minutes later, it would not start. If I jump the pgm-fi plug from ignition power to the fuel pump, the pump runs but if I put in the relay, the pump will not run. It doesn't even do the 2 second prime. I have the factory service manual and I followed the flow chart up until needing a ecu breakout tool that costs about $2000 now. The only odd thing during the test was one pin in the pgm-fi relay plug should have battery voltage while cranking but it only showed about 10.5 volts.

 

is it a mitsuba main relay? did you try a solder reflow?

Main Relay Fix, Troubleshooting (Honda, Acura) and how to solder

i'd swap ecu if that dont work.

 

I replaced the factory relay with a brand new one. The original relay actually tested fine according to the FSM test procedure. I ordered an ECU but I hate throwing parts at a problem instead of actually diagnosing it.

 

well if the ecu is actually good you'd have a spare to send off to phearable or whomever.
then when it comes back you can sell the other on fleabay.

 

Got a reman ECU from HAmotorspots and the car runs fine now!

 

congrats! 8)