How are you priming the fuel system? There is a special pump needed to complete the task correctly.
Live diagnostic data is the only way to tell if there's sufficient rail pressure.

I am priming by adding suction to the supply side of the filter until it is drawing fuel through the filter into a container

Ah. There is a special pump needed which pumps fuel right though the system and back down the return, which ensures there's no air trapped in the pump. The lift pump on these engines isn't very strong at cranking speed, so eliminating air in the pump is important.

If you apply suction to the return side of the filter, that might work.

Will give thst a go

I have now sucked or pumped fuel into every orifice and still no joy. If I pull back the cotton braiding on the fuel line feeding the high pressure pump, no fuel is being sucked into what I presume is the low pressure lift pump incorporated in the high pressure pump. This is at cranking speed. As both the lift pump and the high pressure are mechanical driven by the exhaust cam, then the both pumps are permanently pumping when the engine is cranking or running with the fuel either feeding the fuel rail or being returned to the fuel tank. As i am getting not fuel being pumped then the problem must be the pump(s). Before I buy a new pump is my logic sound. Or could it be something else.

What fuel filter are you using and as above get the hand pump to pull the fuel through.
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