On a 1991 Honda Accord main relay, is that supposed to be grounded to make the fuel injectors work?

On a 1991 Honda Accord main relay, is that supposed to be grounded to make the fuel injectors work? - 1

The wiring of any relay requires one terminal to be grounded.

Yes, all relays use a ground, there are two grounds for the main relay.
1. To the ECU
2.A permanent ground to the thermostat housing.
The ground to the ECU grounds the relay when the engine is turning over. You should hear 3 clicks from the relay ignition on but not start, Check engine light off, and key to start.