The ECU 'main relay' runs both the fuel pump and the ECU. There was a common fault on the 1990 model with this part (there was a recall from Honda about this). The solder connections inside this relay get cracks, then it will not work (fault happens most commonly when car is parked in the hot sun). On the US model, the relay is a reddish-gray box which is located under-dash very near the steering column directly above the silver cruise-control module. You need to unbolt the cruise control module to get to it. You can disassemble and re-solder the relay, or just replace it.
Some of these cars had ignition switch problems, but the relay issue is most common. When you switch the igniton 'On', but do not start, the fuel pump should get power for about 10 seconds (pressurizing the system). You can hear that sound if you listen carefully. If it's silent, then I would suspect the relay.
Soichiro H., February 2008