So I thought I had the problem fixed when it did this before but I guess not. My fuel pump does not come on for start. I have replaced both the ECU and the Main Relay. Worked for awhile but no joy now. All components check good individually but not together. I have jumpered out the ECU ground and pump does come on but it shorts the ECU and does not allow start up. Not sure where to go now. 1989 CRX Si D16A6. Please help.

 

Try switching out other relays for known good relays.
You might be surprised.
I chased a similar problem on a vehicle that gave me grief for nearly 2 years due to the fact that the relay would "sometimes stick" and cause a no start. Spent over 2k @ the dealership had the vehicle towed 3 different times I believe, replaced the ECU, and the Guage cluster all while following the manufacturers diagnostic chart. After all that the problem still remained. It was very frustrating. Turned out to be a flippin relay all along.

Intermittant problems are a PITA.

You can look here for more info...
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/%2A%2A%2A-basics-no-start-diagnosis-101-%2A%2A%2A-1992733/

Roach

 

I read some other threads about the ground wires at the thermostat housing and sure enough that was it. It was corroded so i swapped out the bolt and scraped the wire with my screwdriver and it started. i'm gonna clean it right now that it is home and then seal it up with some high heat rtv. thanks for the info i'm sure it will come in handy next time.