lukasz gt wrote: Renault Master 2 car with a 2.5 dci 100 engine. Fuel comes to the injection, but the comp pressure is low because it does not bump as it should. What is responsible for the pressure from the injection pump. After my thoughts, the injection does not open because the pressure is too low.
Think first of all with what engine you are dealing with. If it really is
dci , not
tDI it is not there
Unit Injector only
injectors Common Rail first of all. The second injectors are not opened by the opening pressure, but by means of strong current pulses delivered by the control computer to the electromagnetic coils or piezoelectric actuators at the top of the injectors.
There is also
injection pump manifold only
high pressure pump (pwc) , secondly. In contrast to the first, the wc pump does not deal with the distribution of the injected fuel dose to individual spring injectors in the so-called injection sequence. It only compresses the fuel to very high pressure in the order
150 (start-up phase) , up to
1800 or even above
2000 bar (200 MPa) in pwc
BOSCH CP4.1. Your pump
BOSCH CP3 It may look like below.
It is a 3-piston pump, radial, maximum pressure 1800-2000 bar, depending on the variety and modification. The role of the low pressure pre-pressure pump meets
gear pump (3).
Familiarize yourself with the basic scheme
Common Rail such as below.
This is the SIEMENS injection system, currently CONTINENTAL, found in most German turbodiesels. Any engine from the family
Common Rail - French, Japanese, Korean, German - with different capacities and power - all work identically, as shown in the diagram. What's more, they all have almost identical pressures and underpressures. The differences are, for example, in the construction of injectors that are either electromagnetic or piezo (third generation CR).
As you can see, there are as many as 4 pressures, including
under pressure (blue color).
In this scheme, the answer to your question is at the same time
"what is responsible for the pressure from the pump?" For controlling and regulating the fuel pressure in the tank (7), he responds
Expense regulator (low pressure dosing solenoid valve) (3) and
pressure regulator (4).
The main valve there is a flow regulator (3) that resides on the low pressure side. As the name suggests, he is
dispensing solenoid Fuel forced through the low pressure pump (2) to the high pressure pump (1). On some systems it is called
suction throttle valve and it also corresponds to his character of work. If the precleaner pump (2) "sucks" fuel from the tank, the regulator (3) is to "choke the suction" so that the pressure is stabilized in the 2.5 to 6 bar fork.
The principle of operation is child's play, the greater the current will feed the computer to the electromagnetic coil of the regulator, the wider the valve will open and the more fuel will be allowed from one pump to the other. The smaller the current, the less green fuel reaching the PCW (1). It follows that the valve regulates the low pressure in a very small area inside the pump housing (green color). The pressure must oscillate within the given limits, i.e. between
2.5 and
6 bar .
At the same time, take note very muchimportant information related to pressure regulation and valves, viz
the solenoid valves do not regulate the high pressure pump even though they are mounted on it. They
they regulate the pressure in the container (7).
This means that pwc does not have any own regulation, the smallest screw that could be used to set the injection angle or anything else. It is a typical pump that pumps fuel from place to place at very high pressure. So, for example, a faecal pump works, but does anyone regulate it? The simplicity of the pwc construction allows for huge pressures, unlike the distributor pump. The latter, despite the similarity of construction, obtains only a maximum pressure of 400 bar, because it has too many seals and mechanical parts controlling the phases of injection, etc.
If, as you say,
the pressure drops , it can mean an electrical or mechanical failure of the regulator (3). It simply does not open wide enough and does not allow the required amount of fuel.
It can also mean a prosaic cause such as clogging the fuel filter with metal chips or other impurities. Also, the most common burning of the fuse will not allow the engine to start. Because there is not enough fuel in the green area, despite the impeccably operating regulator (3).
If it is not there
green fuel it is not there
red . As the saying goes, even Solomon does not pour in vain ... If there is no red fuel, the computer will "sense" it
fuel pressure sensor (8) and will not supply electricity to the injectors (5).
Auxiliary valve is
zrwc (4), which resides on the high pressure side (red color). It works basically in an emergency situation, i.e. when you need a quick refueling to
transfer "c" (yellow), eg during engine fire.
In other injection systemssuch as DELPHI, DENSO, BOSCH (4) is often replaced by a simple relief valve, otherwise safety, which opens after exceeding the limit pressure.
In my opinion you should start with the simplest thing, i.e. reading an external diagnostic datalogger of a motor computer. If the STOP indicator and / or lamp is on
check engine (check the engine), then surely the computer has registered faults in the form of error codes (e.g.
P1234 ). It is enough to read them, understand what is going on, then remove the defect and erase the error memory.
If there are no errors and no information was obtained while driving with the diagnostic laptop on your lap, measure it
low pressure fuel ordinary manometer before and after the filter. The values of the vacuum are in the blue rectangle. If the vacuum is below or above the specified standard - for example, the system itself
zapowietrzył - the entire injection circuit damages, because there is no fuel in the circuit, despite the impeccable condition of all elements.
These are simple things like the construction of a flail, there is no philosophy here, only logical thinking and knowledge of the construction and operation of the fuel circuit. You will learn by heart, you will not forget for the rest of your life.
Pzdr KotBury2
