NATS Immobiliser issue

Hi guys,

I'm currently on with building my k11 micra rally car and I've come into an issue with the immobiliser I believe.

My car is a LHD and it didn't come with a wiring loom so I've taken a 2002 wiring loom from a donor car I got which has now been stripped of everything it doesn't need to be a rally car and also been adapted to make it LHD.

I have left the immobiliser in for now until I can afford a stand alone ecu.
After taking out bits of the loom, for example the airbag wiring, I've tried to start the car again and it won't fire.
The car ran on this wiring loom and ecu when I first put it in the car before I started stripping bits.
I have double checked every bit of wiring and can't see any faults in what I have done.
I just wondered if there is any sort of ecu lockout it can do to stop tampering of the loom?

Any advice would be greatly appreciated...
I'm borrowing a diagnostic computer to plug it in and see what I can find but unsure of what to do if there is an immobiliser fault on there?

Thanks in advance :)