Sportrak wiring harness


I'm hoping somebody can tell me if there are any differences between the main wiring harness from a carburettor engine and one from a fuel injection.
The harness section for the ecu seems to just plug into the existing main loom but the ecu does not appear to be getting power. Also there looks to be a slight difference in the colours of the connector on the main loom.
I got a complete front end harnesses from a feroza 2, am just using the injector/ecu pug in sections as did not think there would be any differences.
To complicate things further a previous owner fitted an immobiliser for which I have no information about.
Any help would be appreciated.