engine cuts out as if immobilesed tried override key no joy. if you turn key it seems as if the car is immobilised the car will start and run but cuts out after a few miles. Help/
Have you checked the connections to the immboiliser and fuel pump? Not sure about fuel pump one but if your immobiliser is the same as mine, there is a large white connection block just next to it and also an earthing point. Worth checking those.
Also check the relays. If it's not the immobiliser, might be something killing the fuel pump elsewhere. They're prone to water ingress in the front service compartment.