[Engine] 1.6 HDi Turns but won't start

[SolentCarAudio]

Hi,

I have a 2007 Citroen Berlingo 1.6 HDi with the DV6TED4 engine.

After changing the injector seals and fuel priming pump (and associated hoses) the van will not start.
The engine turns over fine and the starter motor is brand new, after the old one failed after trying to start the engine.

Checked so far:
Fuel system primed for several hours, even using an electric pump. Fuel filter checked, was only replaced 2 months ago. Fuel appears to be reaching all parts of the fuel system, including the injectors.
One injector was tested whilst removed from the engine, and diesel was spraying out of it while cranking.
Glow plugs tested, over 50% of the end of the plug is glowing red when removed from the engine. Measured resistance of each glow plug is 1.2 ohms. We have powered the glow plugs directly from the battery to rule out the glow plug relay.

I have run out of options and would appreciate any advice, thank you in advance!