my 89 Honda Civic hb has just had its engine rebuild but now the main fuel relay is rapidly clicking and the CEL comes on and off with the clicks, ive replaced the relay but its still doing it. i do do manage to get the car started for long enough to get the car into a gear it will only stay running well in reverse can someone PLEASE tell me whats could be wrong and how to fix it

 

If your main relay is clicking rapidly it may be a problem with ignition. The main relay operates the fuel pump when you turn the key to "on" to prime the fuel pump. When this begins, the CEL comes on and when it is finished, the CEL goes off. Then the relay should click for a third time when you turn the car to "start" and you start cranking it over. When the car starts running the main relay is only operating the ignition line. I'd say check ignition wires and your key switch etc.

 

Check the ground wires on the thermostat housing. It's easy to forget to connect or tighten them during an engine R&R. Did the car ever run properly with the rebuilt engine?

 

the rebuild engine only ran proper for the 10 mins it sat running and 5 mins of driving