According to the official information I have the EWS ECU will cut off the starter relay and the fuel relay if it doesn't recognise the key or the signal to it becomes corrupted. Both of these systems appear to be working as normal.
The engine will run for a maximum of 5 seconds if the following sequence is followed:
Key turned to position 2 for a few seconds to prime fuel system, Fuel pumps are "working"
Try to start car engine fires but shuts down after a few seconds (I suspect when the fuel pressure drops) continued cranking results in engine sometimes catching for an instant but usually engine just continues to crank.
If the sequence is repeated the same result occurs.
My conclusion is that the engine when it fires is using the fuel to the point where the pressure drops on the low pressure side of the system which then causes the low pressure sensor to cut the ECU as described in my previous post. (See other thread)
There is fuel getting to the H.P. pump but don't know if it's at sufficient pressure to keep the engine running. The pressure should be 3.6 bar and the low pressure switch cuts in at 0.7 bar.
I don't unfortunately have a suitable guage.
The diesel specialist said he didn't find any faults but don't know if he tested the fuel pressure on the low pressure side.
Have discounted the cam and crank sensors, high pressure fuel rail sensor and low pressure fuel sensor in the filter head. All these have been replaced by known working units from my own car.
Have checked every connector for cleanliness and security and checked wiring as much as possible including the connections to the ECU.
Injectors have been cleaned and "serviced" by diesel specialist.
Failing anything else I am tempted to try a new in tank pump and then if it doesn't work I can always keep it as a spare for my own which has now hit 80,000 miles. At least we can then rule out any faults on the low pressure side of the system.
Russ