Hi, I have a 91 Lx sedan , that i just finished doing a obd1 b16a2 swap , everything is great , except i have a issue that im not sure which way to go with at this point , why car will run for like 30 seconds then shut off , if i prime the fuel pump 3 or 4 times it will run a little longer but not much maybe 45 seconds , i changed the fuel filter yesterday , and I still have the same problem , 30-45 seconds then dies abruptly it doesn't sputter out - i can hear the fuel pump kick on and prime and it does not sound weak but im not sure , i pulled the return line and inserted it into a bottle and when i prime the car it fills the water bottle up 1 1/2 - 2 inches so i know im getting fuel thru the rail - ive got two main relays (one works sometimes) the other appears to work all the time when the car shuts off there is a loud click at the relay - ive pulled the tank thinking the sock might be dirty its not , what is everyone opinion what should i do , buy a new pump or relay or both? I was told i can jump the relay plug and start the car without it and that would let me know if the relay is bad , but i cant seem to find any information on how to do so I was also told i could run a live wire to the pump to see if thats the problem ..idk what to do at this point and are looking for advice and or direction
thanks

 

An abrupt stall indicates an electrical issue, not a fuel issue, even if the pump stops, [for whatever reason] the engine would "sputter" into the stall as the fuel pressure dropped, a sudden stall is more likely no spark or no injector pulse.
Keep in mind the PGM-FI Main Relay is actually two relays in one housing, the fuel pump relay and the fuel injector relay, if the fuel injector relay fails it will cut power to the fuel injectors and IGP 1 and IGP 2 to the ECU along with power to some engine sensors/valves/solenoids and power to the fuel pump relays coil.

I would start by testing for power to the injectors, a 12V test light is all you need, probe the power lead at an injector, [lead that is the same color at each injector] start the engine and see if there is power at the injector when the engine stalls, if not, replace/repair the relay... Main Relay Fix and Troubleshooting (Honda, Acura).

If on the other hand power remains at the injector you will need to check for injector pulse, [ground pulse] this is supplied by the ECU, and a noid light is used to test that or you can use an LED type 12V test light.
The test is pretty much the same except this time probe the lead that is a different color at each injector, the LED test light should blink when engine is running, if it goes out suddenly, you have an ECU problem.
But before you replace the ECU test and make sure both IGP 1 and IGP 2 have power on them when engine stalls, your 91 may only have one IGP input, try yellow/black A15. 94

 

^All brilliant tests, however, first I would check the main harness ground. I've seen a main ground issue cause all sorts of problems, including something similar to this.

-Amp

 

resistor box

 

where would this ground be ? the one near the water neck/ thermostat ?

OBD1 does not use a resister box


the car started and ran yesterday (i did nothing to it ) ran for a god 10 -15 mins and would start at any point past that now today , it will start and shut off but if i manipulate the throttle i keep it running if i stop it dies