AJ133 engine running lean

[Bullevard]

Dear all,
I have big issue with my own L405 supercharged V8 AJ133 engine.

Long story short, filled up my vehicle with bad Petrol probably, after a mile, engine stalls. Restart and was going again. 
had to drive 300km same day. Was terrible. Max speed reached was 120km/hour. 
When cold start, a lot of black smoke and back fire for a minute or so. 
So far, changed Low pressure fuel pump and filter.
Changed both HPFP 2x including buckets. 
Checked all 8 injectors and replaced 4 for fun with no results at all.
Live data shows the following:
Fuel pump low side 7 bar. Normal. 
Engine startup, 8 bar. should be 50 bar
Engine warmed up, 20 bar max. Should be 50 bar. 
It is almost as the hpfp not working at all. 
Sorry for my frustration since I am now to long busy with this issue. 
My last thought is, could it be that the chain of the hpfp cam has jumper a teeth? Can this actually create this dramatic reduction in pressure? I don’t believe so. 
Any thoughts would be highly appreciated. For now 6 mechanics are scratching their heads. What I am missing here?

Please see these readings from IId tool.
Sam.


PCM-Engine Petrol V8


P2179-00 (64) System too lean off idle Bank 2
( on 10-05-2023 20:15:12 at 127701 km )
P2177-00 (64) System too lean off idle Bank 1
( on 10-05-2023 20:15:12 at 127701 km )
P228F-85 (2F) Fuel pressure regulator 1 - Exceeded learning limits - Too high - Bus signal/message failure - signal is above allowable range
( on 10-05-2023 19:45:28 at 127700 km )
P0087-77 (2F) Fuel rail/system pressure - too low - Mechanical failure - commanded position is not reachable
( on 10-05-2023 19:45:28 at 127700 km )
P00C6-00 (27) Fuel rail pressure too low - Engine cranking
( on 11-05-2023 07:53:11 at 127723 km )