TD5 fails to start

I have a friend who has a TD5 which has covered 80000miles and has a issue with this TD5 in that it fails to start. To date a number of things have been tried , but I will give a brief history of what happened just before it starting failing to start.

Motor ran fine then one day while running it just stopped, it was at idle when it came to a halt, and has not started since.
The motor just turns over as normal but makes no sign of attempting to fire. At ignition switch on you can hear the fuel rail getting pressurized but no fire.

Items changed so far include a new Fuel pump, Fuel regulator valve, Crank sensor and a new Injector harness as oil was found at the red ECU plug. ECU has not been taken apart yet.

My thoughts are it is electrical but that's just a gut feeling.

Is it possible that this has anything to do with the alarm system as there is a immobiliser on this motor and if so how can I bypass/test this, is it built inside the ECU unit.

Next thing I what to look at for him is to see if the injectors are getting the electrical control signal which being from a electronic background I should be able to do for him

Any advice or thoughts on the above or suggestions as to were to go next so we can get this TD5 started

Sounds like she needs to be plugged in... Does anyone have a nanocom near you?

Thinking that myself, I will have a look at the injectors and see if they are getting any control firing signals, that's why I was query if ECU on these motors contained the alarm immobiliser circuitry which if had a issue would prevent a start.

Immobiliser module lives behind the dash binnacle

Has he run a fuel purge? Was it showing any signs of difficult starting? It should start first turn even when cold.
If it starts after a purge, then it sounds like injector seals.
A plug in would help as well.
Mark