i just bought a 93 civic lx with the 1.5 sohc 16 valve, the guy that i got her from said he put 2 fuel pumps, 3 computers, and 2 main power relays in it trying to fix this issue, when i turn the key on, i have to wait for check engine light to go out before the fuel pump primes and allows the engine to fire, any ideas? im thinkin the main relay all fuses are good

 

Some people have had ECUs that were slow to "boot up" and start working so the engine can start. Check that the sensors (MAP and TPS) get their 5 volts when the key is on. This voltage comes from the ECU.

Take main relay apart and inspect the solder joints. The problem is always in the solder job, actual failure of other parts of the relay is rare.

It works by the ECU grounding the wire to the relay which turns it on, then the fuel pump starts. If the ECU doesn't pull the wire to ground, the problem is ECU related. If the wire goes to ground but the relay doesn't pull in, it's relay related.

Also check the ground wires on the thermostat housing. A bad connection there does similar things.

 

So if i had a lazy computer is there a way i could bribe it to make it work as soon as the key is on? Lol just kidding but yea if it is a lazy ecu should i be in a hurry to fix it?

 

Also, where would the main power relay be?