Could someone provide a detailed explanation of the diesel fuel system, please?

[Markwe]

I am now addressing a malfunction in the limp-mode of my 2020 E90 316d, however this information is generally applicable to most BMW diesel vehicles.
Based on my comprehension:
1. The gasoline is contained inside the fuel tank.
2. The submersible fuel lift pump transports the gasoline to a filter.
3. The gasoline is thereafter sent to the low pressure side of the high pressure fuel pump (HPFP).
4. The EKP pump module determines the quantity of fuel.
5. The low-pressure side of the high-pressure fuel pump (HPFP) has a regulator, which is also referred to as the suction valve.
6. The low-pressure (LP) side transfers gasoline to the high-pressure fuel pump (HPFP).
7. The high-pressure fuel pump (HPFP) supplies gasoline to the common rail.
8. The common rail is equipped with a pressure sensor and a regulating valve that allow for the return of surplus gasoline to the tank.
9. The fuel is thereafter supplied to the injectors.
10. Surplus fuel is discharged from the injectors and returns to the tank.

Is my understanding accurate up to this point?
If this is the case, the issue is likely my own responsibility. The problem is diagnosed as a lack of pressure in the common rail immediately after the engine stops, which makes restarting difficult until the pressure in the rail increases. This issue is most likely caused by leaking injector(s) into the cylinder(s), a leaking common rail regulator, or a leaking regulator on the low-pressure side of the high-pressure fuel pump.
I purchased a pre-owned common rail regulator without any modifications, as well as a pre-owned pair of injectors that are compatible. I replaced the EKP module (without any alteration) and I am also considering replacing the LP regulator on the HPFP.

I am concerned about the High Pressure Fuel Pump (known for producing metal particles when it malfunctions) causing a leakage of rail pressure when the engine comes to a halt.

The issue is the activation of limp mode during acceleration, which often results in engine shutdown.
The vehicle has difficulty starting, with a noticeable delay of 5 seconds during the first churning. The diagnosis indicates a lack of residual pressure in the fuel rail.

Apologies for the extended length of the post. Any assistance you can provide would be highly appreciated.

[Markwe]

There are typographical errors in the names "Diesel" and "2010 E90 316D."

[Ledgerciao]

The HPFP is the only remaining component.

[RacingNight]

Are there any issues with the high-pressure fuel pump (HPFP) on the ASV?

[Markwe]

I am unfamiliar with the meaning of "Asv's on the hpfp".
I have not yet completed all of my exams.
I have purchased a new pressure regulator that is compatible with the high-pressure fuel pump and may be installed on its side. I am uncertain about the functionality of it. The suction valve is sometimes marked with a label.
I would want to know how the pressure is released from the common rail when the engine is turned off. The issue is likely caused by either the injector(s), the common rail pressure regulator, or the high-pressure fuel pump (HPFP).

The high-pressure fuel pump (HPFP) cannot be severely malfunctioning if the automobile is capable of reaching a speed of 80mph on the highway. The automobile has a lack of power while accelerating in urban traffic.

[RacingNight]

An anti-suction valve, also known as an anti-syphon valve.

Essentially prevents the backward flow of gasoline from the pump.

[Markwe]

Thank you.
It would be quite desirable if altering that resolves the issue.
Is failure a frequent occurrence?

[RacingNight]

I have had issues with them occurring in several automobile brands, but generally, I avoid dealing with diesel vehicles.