I have a 96 honda accord ex which had a blown engine. I swapped over another engine and was able to get it to run twice, but since then, it just cranks over and feels like it wants to start up but then dies again. I'm getting spark, timing isn't an issue. I'm getting fuel to the fuel rail but it seems as though the injectors are not injecting fuel into the cylinders. Someone told me that it may be the fuel injector relay on the passenger side of the car, on the firewall underneath the fuse box. Would this be the culprit to why I'm not getting fuel to the engine? I know the vehicle runs because it did run, twice. Would anyone know what the problem is, and how to fix it?

I'm having the same problem but I've tested a few more things than you (possibly). Have you tested the main relay yet? That sounds like it could be right up the main relays alley. I used an online manual to test mine, do you have a manual? It'll tell you which terminals to check, which ones to ground out, etc.

I have a 96 honda accord ex which had a blown engine. I swapped over another engine and was able to get it to run twice, but since then, it just cranks over and feels like it wants to start up but then dies again. I'm getting spark, timing isn't an issue. I'm getting fuel to the fuel rail but it seems as though the injectors are not injecting fuel into the cylinders. Someone told me that it may be the fuel injector relay on the passenger side of the car, on the firewall underneath the fuse box. Would this be the culprit to why I'm not getting fuel to the engine? I know the vehicle runs because it did run, twice. Would anyone know what the problem is, and how to fix it?
Try the fuel pump relay

I'm sure you have checked but, have you checked over the harness carefully to make sure you haven't missed anything?

If you can get a service manual, they should give you testing specs for the injectors voltages, get a multi meter and check them and their signal wires.

I just had the same problem with my 91 dx hatch it is the computer telling your injectors not to fire I replaced everything one by one until the computer fixed the problem. I got one at a junkyard for 25$ it was worth it

I myself replaced the main relay, Fuel pump, fuel pump relay, ignition computer module, fuel filter, o2 sensor, map sensor, checked all grounds from thermostat housing and it was the computer. Unplug a injector and see if when you turn your key on with a test light see if you have power to the injectors if so then your computer will tell them not to pulse which is sending fuel.