maybe worth checking your fuel pressure
Yes I think I will, I’ve got a fuel pressure test kit but haven’t worked out which of the adapters to cobble together! Although I haven’t checked the fuel pressure it does have a new (cheapo) fuel pump and new (genuine) filter housing. It didn’t make any difference so I assumed fuel pressure wasn’t a factor, maybe it is.
I also wondered if perhaps although there is power to the glow plugs I have only put a multimeter to one, and I also removed one to physically see it glow up, but again only one. If one or more of the connectors is knackered it’s not going to do anything. If I leave the engine idling for 15-30 secs there are no issues at all, and generally it runs very well with no issues.
I’ve done several compression tests varying the order I did the cylinders each time and compression was fine.