2003 Ducato 2.8 JTD cranks but won't start

[Louisk56]

Hi there, My 03 Ducato with the 2.8L JTD engine won't start. It cranks and fuel gets to the high pressure fuel pump but nothing comes out to the fuel rail. However It runs on easy start. Any suggestions? I suspected the fuel pressure solenoid pictured below but have replaced it with no joy. And it is also not the inertia accident switch. Before Iook at replacing fuel pump itself does anybody else have any suggestions? I'm desperate! I measured the voltage I'm getting to the plug for the fuel pressure solenoid on the back of the pump and I have 12V at one pin and 3.6V at the other. Is this correct? Just trying to rule out immobiliser issue. Thanks in advance