I just completed an engine swap in my son's 88 CRX HF. The car started, but when shut off refused to start again. I checked the computer, and got a fault code for ignitor and fuel injection. I replaced the distributor, throttle body, wiring harness, fuel relay and filter. Had good pressure and the car started fine. After driving for about 30 minutes, I shut it down, and it wouldn't restart. I cleared the fault codes and retried. Got the fuel injector code again. Checked everything, the car started and ran fine for a day. Tonight.....you got it! no start. This time, I didn't even get a start up flash from the computer, so I replaced it. No start....fires on starting fluid, but no go on fuel injection. I'm running out of hope and my parts car is almost bare. Any ideas?

 

Main Relay?

 

http://www.fourthgenhatch.com/mainrelay.html this will tell you how to change it.. Courtesy of fourthgenhatch

 

Yeah it sounds like it could be a Main Relay. I guess its just a coincidence it happened right after your swap was done.