defender td5 fuel problems etc.

I have a 1999 TD5 Defender. It won't start!
I have replaced the fuel relay but it won't pull in as its not getting the signal from the ECU.
I have checked the connection from the relay to the ECU and the earths.
If I hold down the relay contact the pump works.
The fuel pump has been changed etc.
The wiring loom is free from oil.
The Nanocom read only Ambient air circuit as a fault, can this stop the ECU?
Not sure what next to do, any suggestions

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