I have a 90 civic dx, won't start when hot outside. ECU blinks 16 times when key is in the on position without cranking the engine. I've heard this indicates a problem with the fuel injection and that the main relay might be the culprit. Where is this located and how do tyou replace it?

 

By the drivers feet. Should be a little grey box. They are about 65 bucks.

 

thanks, I found a rectangular black box bolted with one bolt above and to the right of the brake pedal with a small wire harness connected to it. Could this be it?

 

take a pic. go to a junkyard and get a couple for cheap