G4 Plug in permanently holding inj 3

[jewfab]

G4 Plug in on S13 SR20DET

Some wiring to the coils was damaged and caused a blown fuse. Half a lap after repairing it the ecu started holding #3 injector to ground. It is back feeding around 9v to the ecu and keeping the ecu alive while the car is off. I cannot fault the wiring and haven't found any issue while plugged in with the software. Everything else works fine. The car still runs as normal on the other cylinders. Unplugging #3 injector removes the back feed and allows the ecu to turn off.

[Adamw]

I'm going to ask @Simon to comment on this one since he knows the internals better than me.   It sounds like you possibly have a damaged injector drive but that doesnt explain the "back feed".  Your inectors should not have power on the other side when you turn the key off so it sounds like there might still be a problem with the wiring too?

Anyhow, hold off until Simon gives his advice.

[Simon]

I think on the nissan the injectors are hot fed. So will have a permanent fed to them direct from the battery.

Generally when a drive is damaged it will short to ground but I would not then expect a back feed.

But I do think there is drive damage that will need to be repaired.