Great we can test a few thing controling the injector
Multi meter on volts
One of the wire going to all the injectors will be the same colour that's the power feed
If you remove the connector and place a pin in this terminal it should measure voltage between here and the negative battery terminal
Multi meter on ohms the two pins on top of the injector should measure just under 15 ohms
The computer control wire to the ECU is a little more tricky to check, let's hope the first two checks find the fault