Toyota Repair: fuel injector wire, wire harness, fuel injector

Question
i have a 1986 mr2 that the two wires on the injector plugs are both positive. I have checked all of the relays and fuses and the grounds but no luck yet? can you guide me in the right area?
it is a 4 cyl. non turbo automatic.
motor has been changed with same type motor.

Answer
I'm not quite sure I understand, are you saying that on the wire harness side of the injector connectors both terminals measure at 12 volts?
There should only be 12 volts present to one terminal of the connector, the other side is grounded by the computer to turn the injectors on and off.