I'm converting my '93 non-turbo from old to new style injectors. was told I needed to add a relay to cut power to injectors when key is off. Can anyone tell me how to do this without affecting the ECU? have seen instructions on splicing two wire together in place of adding a relay but this method would also cut power to ECU which erases all the stored ECU codes. I want to cut power to injectors but keep power on the ECU. Help...