Rep Power: 0

Hi everyone. Situation: 03 civic dx sedan, 223k miles, 1.7L D17a. I recently put the engine in (October 2025), hooked everything up, and tried to start it. No joy!!!
I can clearly hear the fuel pump power up. No engine lights (don't know if there should be any, after sitting for 4 years with no battery?!?!) I did replace one of the relays (brown, far right, behind glove box.) I checked all of the fuzes, and they are good (not burned out.) I also checked all of the coils; no spark. Any suggestions??? Thanks for all of your help in advance...

 
Rep Power: 126

There's a lot of things it could be. The anti-theft system can cause it (there's a pretty good diagnostic pathway on here somewhere to verify its function), and I'm pretty sure no communication/a bad crank position sensor cuts spark (it's been a long time since I've had my '01 but I recall that being an issue for me), but it's more than likely a bad connection/ground somewhere.

If it's not those and you're able to confirm that the fuses and harnesses are good (beyond a visual check - use a multimeter), there might be an issue with the ECU itself. It's pretty common for failing when the alternator bolts aren't tightened fully.

 
Rep Power: 0

Cool. Thanks FRSam!!!