Smax cutting out white driving, shows spanner light and says check manual. 
push button to start and it just cranks, cycle ignition back of and on again and fires first time. 
just been out and read codes on FORScan on my phone. 

P0251 - Injection Pump Fuel Metering Control A. P228C - Fuel Pressure Regulator 'A' Exceeded Control Limits - Pressure Too Low

any ideas on where to start ? 

If this model uses a tank fuel pump, make sure that one is priming correctly.

Otherwise it could be the FPR at fault, or the HP pump not providing enough pressure, or a dodgy injector preventing the rail from maintaining pressure.

So I just got mine sorted eventually. Had a new high pressure fuel pump and a full set of injectors ! 

Ouch, my first point for any fuel issue is change the filter but it obviously went way beyond that but can't understand why injectors were needed?
However, thanks for coming back with the solution!

When diesel HP pumps fail, they generally create metal fillings which are forced through the fuel rail and into the injectors under extreme pressure.  Very rare to get away with only replacing a HP pump.

That said, I'm sure some garages do replace pump or injectors unnecessarily in some cases.  The owner has no way of knowing or proving that.

On 10/23/2024 at 3:45 PM, TomsFocus said:

When diesel HP pumps fail, they generally create metal fillings which are forced through the fuel rail and into the injectors under extreme pressure.  Very rare to get away with only replacing a HP pump.

That said, I'm sure some garages do replace pump or injectors unnecessarily in some cases.  The owner has no way of knowing or proving that.

Filings could perhaps be noticed in the filter housing (some fuel and filings recirculated in return line?) which would at least provide evidence for the owner of that rather expensive problem, Ouch!
I'm hoping the use of this (or similar) as well as improving running (no noticeable massive effect on MPG but claimed Cetane improver/detergent/lubricant etc properties) gives premium diesel for half the price of premium fuels from garages:
https://archoil.co.uk/
Any other experience welcome

19 minutes ago, Shearers said:

gives premium diesel for half the price of premium fuels from garages

Total Bo11ocks. 🙁

Regular diesel is around £1.45 per litre

Premium diesel is around £1.65 per litre

So what actual saving is this bottle of snake oil going to give ?

How much is a bottle of snake oil, I assume it's not free ?

4 hours ago, unofix said:

Total Bo11ocks. 🙁

Regular diesel is around £1.45 per litre

Premium diesel is around £1.65 per litre

So what actual saving is this bottle of snake oil going to give ?

How much is a bottle of snake oil, I assume it's not free ?

Thanks for that positive helpful comment which I don't expect 😉

£26/litre treats 1000 l (1ml/l) so 3p/litre?

Doesn't save but gives premium diesel without your quoted 20p/litre premium.
If you try it (like anything) and it doesn't work for you then so be it - just seeking other user opinions regardless.