Fuel pressure regulator VAZ-2114: signs of malfunction, repair. Fuel system VAZ-2114

All engines with an electronic fuel injection system are equipped with devices that maintain the required fuel pressure in the fuel line. In the power unit VAZ-2114 this function is performed by a special regulator. It is thanks to him that gasoline under pressure comes to the nozzles in the right amount, depending on the mode of operation of the motor.

In this article we will talk about what the VAZ-2114 fuel pressure regulator is, how it is arranged and where it is located. In addition, consider its possible malfunctions and methods for their elimination.

Features of the design and principle of operation

Structurally, the fuel pressure regulator VAZ-2114 is a membrane bypass valve, enclosed in a metal casing. It is mounted on a ramp, inserted into it by one of the branch pipes through a rubber seal. The other output of the RDT is connected to the fuel line. To determine the magnitude of the load on the engine, the regulator is connected to the intake manifold by a vacuum hose. Thus, the fuel on the one side comes from the fuel pump, and, on the other hand, the air pressure and the spring force of the valve.

The fuel pressure regulator VAZ-2114 has a fairly simple operating principle. When you press the accelerator pedal, an excess pressure is created in the intake manifold , which opens the valve, allowing more fuel into the ramp. When the throttle valve is closed, the air pressure in the intake pipe is weakened. The valve thus opens in other party, letting out gasoline back in топливопровод.

Symptoms of Malfunction of RDT

The faulty fuel pressure regulator VAZ-2114 does not carry a critical threat, but its failure violates the stable operation of the engine. Symptoms of a RDT failure can be:

• Difficult start of the power unit;
• Unstable crankshaft turns idling;
• Decrease in power characteristics of the motor;
• Loss of dynamics;
• The occurrence of "dips" when you press the accelerator pedal;
• Increase in fuel consumption.

Having found out the listed signs of malfunction of RDT, it is necessary to diagnose the device and determine the cause of the failure.

Possible Malfunctions of RDT

Given that the design of the pressure regulator is mechanical, irregularities in its operation can occur quite often. The most common faults of the device include:

• Weakening of the diaphragm spring;
• Wedging (podklinivanie) the valve;
• Clogging of the regulator;
• Violation of the tightness of the connection between the regulator and the ramp body.

Failure of the diaphragm spring causes the valve to not cope with the air pressure coming from the intake manifold. As a result, the pressure and the amount of incoming fuel are reduced.

The jamming of the valve leads to uncontrolled feeding of fuel into the collector and its "withdrawal" into the fuel line. In this case, the consumption of gasoline increases, and the engine stops normally starting because of interruptions in the supply of fuel.

Similar signs of malfunction can be observed even when the regulator is clogged. Dirt and deposits reduce the capacity of the system, as a result of which the fuel pressure is significantly reduced, the engine "chokes", and the normal idling disappears.

If there is a leak in the connection between the regulator and the ramp, the air pressure may drop, which again leads to a reduction in the fuel head.

What you need to check the system pressure

In order to verify the correctness (malfunction) of the RDT, as well as the entire fuel system, it is necessary to determine the fuel pressure value. Naturally, this will require a special tool. It is called a fuel manometer. It is better if it will have a mechanical design and a scale of up to 10 kg / cm2. In addition to the fuel gauge, you will need:

• A section of a hose of a high pressure (internal diameter of 8-10 mm);
• A few corresponding to the diameter of the hose clamps;
• Pliers;
• screwdriver;
• Cap for nipple;
• Fuel collection tank;
• Dry clean rag.

Pressure measurement modes

Before checking the pressure in the fuel rail, it is not superfluous to find out how this process is carried out. In order to be able to more accurately determine a possible malfunction, pressure measurements must be carried out in several modes:

• With the ignition on (without starting the power unit);
• With the engine running at idling speed;
• With the vacuum hose disconnected from the regulator (to check the operation of the RTD);
• With an overlapped hose re-fuel drain;
• In the overdrive mode.

What should be the pressure when measuring in different modes

According to the information of the manufacturer, for VAZ-2114 the pressure in the fuel rail should be:

• With the ignition on - 2.9-3.0 kg / cm2;
• With the engine running - not less than 2.5 kg / cm2;
• With vacuum hose disconnected - 3.3 kg / cm2;
• With an overlapped back drain hose - 7.0 kg / cm2;
• At peregazovke - 3,0-2,5 kg / cm square.

How to check the pressure in the fuel rail

The order of the pressure measurements is as follows. First, we connect a fuel pressure gauge to one end of the hose, fix the connection with a clamp. Unscrew the cap on the fuel rail (on the side opposite the one where the RTD is installed). We substitute a fuel tank for the fuel. The cap for the nipples is pressed against the central protrusion, thereby squeezing the fuel pressure in the system. This process is mandatory! Further, without removing the container, unscrew the locking nipple completely.

When the fuel remains in the container, put the other end of the hose on the union and fix it with a yoke. We turn on the ignition and wait until the gasoline pump pushes the fuel into the system. Check the pressure and compare it with the recommended one.

After that, we start the engine and make measurements at idle. The working capacity of the fuel pressure regulator is checked when the vacuum hose is disconnected from it and on the operating power unit. If the pressure has increased to 3.3 kg / cm2, the regulator can be considered serviceable. If it has not changed, RDT, most likely, has become worthless.

Similarly, we make pressure measurements with an overlapped hose "return", as well as in the mode of perehazovki.

Repair or replacement

If the check confirms the failure of the RTD, it must either be repaired or replaced. However, here it should be noted that it is simply impossible to buy at least some spare parts for this device, so it is much easier to purchase a new fuel pressure regulator VAZ-2114, the price for which does not exceed 800 rubles.

Replacing RDT

Replacement of RDT can be carried out both with the fuel rail removed and without dismantling it. The latter option is more preferable, since it takes less time. But before removing the fuel rail or the regulator itself, do not forget to reduce the pressure in the system in the way described above! Otherwise, the entire engine compartment will be splashed with gasoline.

So, let's look at how the VAZ-2114 fuel pressure regulator is replaced without removing the ramp. This will require:

• The key to "10";
• The key to "17";
• The key to "24";
• Hexagon on "5";
• A screwdriver with a cross bat;
• Clean dry rag.

The order of performance of works

1. First, disconnect the negative terminal from the battery (key to "10").
2. Disconnect the vacuum hose regulator from the intake manifold.
3. Using the key on the "17" unscrew the nut of the drain hose. Disconnect the hose.
4. With a cross screwdriver, unscrew the bolt of the clamping plate of the return line.
5. Using the hex key on the "5" turn the fixing screws RDT to the fuel rail.
6. The key for "24" is unscrewing the nut that connects the connecting pipe of the drain hose and RDT.
7. Dismantle the fuel pressure regulator.

Here, in principle, and the whole process. Installation of RTD is in the reverse order. Important: do not lose the rubber seal that comes with the regulator. Without it, the connection of the RDT and the fuel rail will be leaking, which will lead to a change in the value of the working pressure in the system.

Some useful tips

To ensure that the fuel pressure regulator does not cause trouble for you and works as long as possible, use these tips.

1. When trying to replace the RDT, buy only the brand-name device recommended by the manufacturer.
2. Fill in the tank of the car only high-quality fuel. Do not use fuel additives of incomprehensible manufacture.
3. Do not forget to replace the fuel filter in time.
4. Check the fuel pressure in the system every time. When troubleshooting, remove them in a timely manner.
5. Having found out problems with the regulator, do not pull with its replacement.