Originally Posted by
ChrisS
Based on your information, I think it's the main relay. (Jumpering terminals = working fuel pump)
How did you inspect the main relay's solder connections? (Pull the plastic cover off and look at the connections using a loupe; any discoloration in the solder could be cracking)
I'm pretty sure the main relay also supplies power to the ignition circuit.
Simple ECU test: turn ignition switch to ON, check engine light should light up, wait 5 or 6 seconds, check engine light should turn off.
picture of main relay solder connections with cover removed:
-circled in red = cracked solder
-circled in yellow = suspected cracked/heat stressed solder
(from my 1991 CRX Si with maybe 200k)
[ATTACH=CONFIG]84953[/ATTACH]
detail:
[ATTACH=CONFIG]84954[/ATTACH]
Thanks Chris appreciate it. I took out the relay again and double checked the solder joints with a magnifying glass, based on your photos. The solder joints still look like new on the relay. Maybe because it has low miles and was kept in a mild climate.
I guess it could be the relay. Maybe the cracks in the solder are not obvious or noticeable.