Still haven't pulled the NPS, but things seemed better after fuel/oil filter changes.
I don't know if it's related, but when cold in the mornings, I completely lose all throttle response. I pull out of the driveway, put it in first and put my foot down and nothing.
Thought it was my gearbox/clutch at first, as it's on it's last legs. But when it did it again today I had more time to fiddle. Managed to change gears/wriggle gear lever etc and no changes to lack of revs. After a while of sitting idle, it came good again.
Only to do it again mid corner about 500m down the road. Lost all power, had to pull over and wait 10 seconds for it to come back.
Seems related to me, jerking car/lack of power. I'm going to try and take it into one of the better diesel guys in town and see what he says, unfortunately money is very tight.