The gas tank of any car always contains vapors formed due to a decrease in atmospheric pressure or heating of the fuel. In order to prevent the leakage of fuel vapors into the vehicle, a special gasoline vapor recovery system (VPSU) is installed. Thanks to it, the vapors retained by the adsorber (essentially activated carbon) enter the intake manifold and burn in the engine cylinders. To regulate the amount of gasoline vapor coming from the adsorber to the manifold, a special solenoid valve is used.
Principle of operation
The adsorber itself allows fuel vapors to accumulate in a special place - the separator. As a result, gasoline turns into condensate and goes back to the tank. Vapors that have not undergone treatment go through double valves of the system, one of which prevents fuel from spilling out during an emergency (for example, a coup), and the second “is engaged” in regulating the pressure in the tank. The adsorber purge valve is located under the hood, and the adsorber itself is located on the tank. The control unit ensures the normal operation of the entire system: it ventilates and removes condensation.
Description of design
Engine power system diagram
: 1 - separator; 2 - filling pipe; 3 — hose for supplying fuel vapor from the tank to the separator; 4 — pipe for removing fuel vapors from the separator to the adsorber; 5 — ventilation tube; 6 — ventilation tube hose; 7 — filling pipe hose; 8 — fuel tank; 9 - tee; 10 - adsorber; 11 — fuel supply tube to the fuel rail; 12 — tube for supplying fuel vapor to the solenoid valve for purge the adsorber; 13 — solenoid valve for purge of the adsorber; 14 — fuel rail with injectors; 15 — throttle assembly; 16 — fuel supply hose to the tee; 17 — fuel filter; 18 — fuel supply hose to the fuel filter; 19 - fuel module.
Fuel is supplied from a tank installed under the bottom in the rear seat area. The fuel tank consists of two stamped steel parts welded together. The filling pipe is connected to the tank with a gas-resistant rubber hose. A ventilation tube is welded into the upper part of the filling pipe, connected to the tank with a plastic hose. The ventilation tube is used to remove air displaced from the tank when it is filled with fuel. The fuel tank ventilation inlet and outlet valves are built into the filler plug.
Fuel module The fuel module, including the fuel pump, fuel pressure regulator and fuel level sensor, is installed in the fuel tank. For rough fuel cleaning, there is a strainer at the module inlet.
Fuel level indicator sensor The fuel level indicator sensor controls the operation of the dial gauge and signaling device located in the instrument cluster.
Fuel pump Fuel pump - electric, submersible, rotary. The fuel pump is turned on by a command from the electronic control unit (controller) when the ignition is turned on, through a relay. The pump creates a pressure in the system that exceeds the operating pressure in the fuel rail
Fuel filter From the pump, fuel is supplied under pressure to the fuel filter. The fine fuel filter is non-separable, with a paper filter element. The filter is mounted on the fuel tank bracket, on the right. There is an arrow on the filter housing that must coincide with the direction of fuel movement.
Fuel pressure regulator with o-rings After the filter, a tee is built into the fuel delivery line, through which fuel is supplied to the fuel rail and the fuel pressure regulator located in the fuel module. The fuel pressure regulator is a valve that opens when the fuel pressure in the line exceeds, releasing part of the fuel into the tank. The pressure regulator is non-separable and must be replaced if it fails.
Design and operation of the adsorber purge valve
The KPA is an electromagnetic locking device that operates from the vehicle’s on-board network. The valve consists of:
- plastic case;
- valve with spring;
- windings;
- metal core;
- connector
When the vehicle's engine is turned off, no voltage is supplied to the valve and it remains in the closed position. That is, on the motor side, the system that captures vapors is blocked. At the same time, the adsorber begins to “collect” vapors. When the power unit starts, voltage is applied to the valve, causing it to open and fuel vapors to enter the intake manifold. As soon as the ignition is turned off, the control unit is de-energized and the pipeline is closed: no vapors enter the receiver.
Cars of a high price category have a more complex evaporation system. Such machines have special sensors that can “calculate” the amount of air and vapor as a percentage. This allows you to more accurately control the supply of gasoline to the injector.
Signs of a malfunction of the control unit
First, start the engine: at idle or in cold weather, you will hear a characteristic, barely audible chirping sound. It indicates that the valve is working properly. In order not to confuse this sound with the noise from a working timing belt, sharply press the gas. The character of the chatter should not change. The following signs indicate a malfunction of the control unit:
- lighting of the CHECK signal on the instrument panel;
- determination of error PO441 during testing;
- increased gasoline consumption;
- unstable operation of the power unit when driving;
- unstable idle;
- increase in CO2 content;
- a hissing sound when unscrewing the tank lid (a vacuum has appeared);
- the appearance of a fuel smell in the cabin.
Valve check on site
You will need a tester (voltmeter, multimeter) and a screwdriver. The KPA itself is installed on the radiator frame. The device can be recognized by seeing two tubes approaching it, through which the evaporation moves. Further:
- disconnect the electrical connector from the control unit by releasing the block lock;
- using a multimeter, check for the presence of voltage by touching the negative (black) probe of the device to ground, and the red probe to “A” (the letter on the block connector);
- turn on the ignition: the multimeter should show the vehicle's on-board voltage. If not, check the wiring.
How to check the adsorber valve removed from the car
You need to take a medical syringe of suitable volume, simply pull out the piston 2-3 cm and connect it to the outlet fitting. If you press on the piston, it will move with difficulty, which indicates that there is pressure in the valve. Now connect the battery to the electrical part of the control unit and press the piston again: the resistance should disappear. If this does not happen, you will have to buy a new valve.
Injection system on Kalina
The system that serves in the Kalina car to capture fuel vapors prevents their unplanned leakage into the atmosphere. These vapors are formed due to heating of the fuel in the gas tank, as well as when atmospheric pressure decreases. The vapors do not escape, but accumulate in the system; when the engine starts, they enter the intake manifold and burn in the power unit. To regulate the flow of fuel evaporation from the adsorber into the intake manifold receiver, the Kalina adsorber purge valve is used. This valve is installed on all cars with an injection-type engine. Its location is usually under the hood.
The system includes a special adsorbing mechanism consisting of technical activated carbon, a special valve with an electric-magnetic pulse and functional pipelines suitable for it.
The entire system is based on a so-called adsorber, which is capable of collecting all the fumes from the gas tank. Small granules of technical activated carbon, which are part of the absorbent part, absorb gasoline vapors and retain them inside.
Why do you need a gasoline vapor recovery system?
Injection vehicles (including Kalina), whose environmental class belongs to Euro-3, must be equipped with an EPS. This prevents fuel vapors from entering the atmosphere, polluting it. In addition, the system guarantees more stable operation of the power plant and saves gasoline. How to check the adsorber valve included in the SUBS and how it functions will be discussed further.
The principle of operation of the fuel system
An adsorber is a small part in a car designed to collect all gasoline vapors. The system allows fuel vapors to accumulate in a specially designed place called a separator, converting them into condensate and releasing them into the gas tank.
Valve on car
Untreated gasoline vapors pass through double system valves. The first valve is gravity and serves to protect fuel from leaking out of the gas tank during an emergency vehicle rollover. The second valve regulates the pressure created in the fuel tank.
Passing through the entire fuel system, gasoline vapors reach the adsorbing chamber and are absorbed by the activated carbon contained in it. When the engine starts, the purge valve starts to operate. If it is faulty, this may result in a loss of power from the power unit and increased fuel consumption.
The adsorber purge valve is installed inside the device filled with activated carbon. The device itself is located on the gas tank. The purge system is designed to ensure that everything functions correctly and without interruption. Ventilation and condensate removal are the main purpose of this electromechanical unit.
A slight chirping sound when the Kalina engine is turned on in cold weather or at idle speed means the canister purge valve is operating. To distinguish this noise from the sound of a faulty timing belt or rollers, you just need to sharply press the gas pedal - the chattering noise should not disappear or change. If this happens, then the cause of the noise needs to be looked for elsewhere.
Automotive absorber design
In simple words, the absorber design is a plastic jar with a filled filter catching element. The best substance for trapping and neutralizing fuel vapors is activated carbon.
The absorber consists of:
- Separator. The separator captures gasoline vapors and sends them back to the fuel tank.
- Gravity valve. The gravity valve protects against fuel overflow if the car overturns. The valve blocks the movement of fuel.
- Pressure meter. The pressure sensor performs an important function - it monitors the vapor pressure in the fuel tank. When the maximum permissible pressure in the tank is reached, the sensor opens and releases the pressure.
- Filter element (activated carbon). The filter element in a car absorber is carbon in large granules. Large granules allow vapor to pass through the layer of carbon powder and condense.
- Connecting tubes. Connecting tubes serve to connect all structural elements.
- Solenoid valve. The solenoid valve changes the fuel vapor recovery modes.
Diagnostics of the canister purge valve
A failed adsorber valve is dangerous because the gas tank begins to be poorly and poorly ventilated. This leads to deformation and damage to the fuel pump. A desiccant layer that is not well ventilated can cause fuel to accumulate in the intake manifold, causing poor engine performance.
A faulty canister purge valve is to blame for dips at idle. The Kalina engine has weak thrust. When the motor is running, the characteristic chirping sound will not be heard if the valve is faulty.
When unscrewing the gas tank cap, you need to listen carefully. If a characteristic hissing sound appears, this means there is a vacuum in the tank, that is, the ventilation system is faulty. If any signs of failure appear, the adsorber valve should be replaced with a new one. A faulty Kalina valve will affect the filtration and purge system. It will poorly collect and accumulate fuel vapors, and they will leak out. This situation will be indicated by the unpleasant smell of gasoline in the cabin and near the car.
Of course, it is worth checking other components of the fuel system. For example, a vapor leak may occur due to a loose tank lid or a hole in it. But if after checking the entire system the cause is not identified, then the purge valve is faulty.
What happens if you remove the fuel vapor absorber valve
Is it possible to remove the valve completely? Some people do this, thinking that because of the valve, fuel consumption increases and the car accelerates more slowly.
In fact, if the adsorber and valve are working properly, then the internal combustion engine, on the contrary, works like a clock and fuel consumption is at the optimal level. The savings are not as noticeable from burning off the remaining fuel vapor, but there is also less choice for the atmosphere.
To the question, is it possible to remove the absorber valve completely? Answer: yes, you can. The engine is not affected by its presence or absence. It only affects if it is installed and faulty.
Disadvantages of a car without a valve and absorber:
Advantages of a machine without valve and absorber:
Owners of carburetor cars, I think, remember how the car’s interior often smelled of gasoline, which is why some people get headaches. For this alone, it is better not to remove the valve and absorber, but to replace them in a timely manner in case of breakdowns.
Valve repair
Checking and purging the valve
The first signs that the Kalina adsorber needs to be repaired are the appearance of a persistent smell of gasoline in the car interior and difficulties that arise during draining the fuel. For repairs, it is necessary to remove the adsorber and disassemble it. Since the device is usually solid, for disassembly you will need to cut off the cover. This can be easily done with a regular file. After repair work has been carried out and replacement of the main parts, the cover is usually simply sealed. For complete sealing, the seams are treated with resin. The resin dries within 12 hours. After this, it can be lightly sanded to bring the filter into proper shape.
Spent and unusable coal is poured out of the adsorber. Foam rubber is suitable as intermediate filters. Remove the old filters and replace them with new ones, prepared in advance. Some craftsmen believe that foam rubber is not particularly effective and will allow all the dirt and coal to pass through, so filters can be made from felt. You can place a piece of cotton fabric between the device and the felt, which will prevent small threads from getting into the system. The resulting gaskets are glued to the base and treated with sealant.
New coal can be obtained from gas mask boxes. It is important that it is completely dry, so dry it thoroughly before adding it to the system.
When the dry coal is filled in, felt filters are installed again. All the plates and springs are put in place, and then the filter itself. As can be seen from the above, it is not difficult to diagnose and repair the Kalina absorber valve; you can do it yourself. Good luck!
Purpose of the adsorber purge valve
In the Lada Kalina model, as in principle in any other car equipped with distributed fuel injection, an adsorbing system is necessary to localize the resulting gasoline vapors. They accumulate inside the tank after the engine stops, and after a certain time necessary for the transformation of these vapors into a condensation state, they turn back into liquid fuel. The remaining volume of vapor that failed to return to the tank moves to the adsorber, where it is retained by two valves. The first (gravity type) is necessary to prevent fuel spillage when the LADA Kalina body turns over (in an accident, etc.), and with the help of the 2nd, the pressure indicator inside the tank is monitored.
Having overcome these valves, the vapors move into the cavity of the adsorber, which is made in the form of a can filled with activated carbon. Immediately after starting the engine, the vapors accumulated inside the tank are sent to chambers where they are burned.
To ensure that the circuit of this unit is ventilated and has the ability to regulate the volume of vapors, the adsorber contains an electromechanical adsorber purge valve for purge (KPA). The adsorber sensor is controlled by a special controller.
If a malfunction occurs in this unit, the LADA Kalina engine immediately reacts to this by increasing fuel consumption and reducing power. Also, if the adsorber sensor does not work correctly, this can cause unsatisfactory ventilation of the tank or even damage the fuel pump.
How to check the operation of the sensor? To diagnose the system, you need to take into account a few simple signs. A malfunction of the adsorber can reveal itself as engine failure at idle speed, in addition to which there is a presence of fuel smell inside the Lada Kalina’s cabin. It is in this case that it will be necessary to immediately replace the control unit, otherwise there is a risk of significant damage to the engine components and elements of the fuel supply circuit. Now you know how to check the system.
Additional features
Of course, initially, created to create environmentally friendly engine operation, the Lada Granta adsorber, the price of which is insignificant, was underestimated. Manufacturers tried with all sorts of tricks to circumvent this newfangled trend, but the law obliged all car manufacturers who did not comply with this innovation to pay heavy fines.
Although AvtoVAZ has never been known for its large exports, it was forced to take measures to install an adsorber, since it has a small, but still a sales market. Today, the adsorber is installed on the Lada Granta without fail, since world research has revealed the following capabilities of this component:
– reduction in gasoline consumption
A similar result is achieved because the adsorber valve allows gases to be driven back into the gas tank, from where they enter the engine, which, when warm, is capable of processing them. If this device is missing, or the canister valve itself does not work, Granta loses fuel, which significantly increases consumption.
– normalization of exhaust system operation
Thanks to filtration, the likelihood of premature wear of the system and its components disappears.
Changing the purge valve on Kalina
The replacement procedure itself is not a complex undertaking. To perform this, the owner will need to acquire a regular Phillips screwdriver and know where the valve is located.
Below we provide an algorithm of actions that allows you to quickly and efficiently complete this procedure.
- Disconnect the corresponding terminal from the negative terminal of the battery.
- You will need to disconnect the power connector from the valve itself.
- For ease of access to the unit, we move the suction pipe of the intake system slightly to the side together with the “Max Air Mass Airflow” sensor. For this purpose, use the indicated screwdriver to loosen the clamp of the pipe and perform the action.
- Now we proceed to dismantling the unit. To do this, disconnect a pair of fittings located on the sides of the product. One of the fastening elements is fixed with a latch and to dismantle it, you will need to recess the latch, then lift the antennae and finally tighten the fitting to the side.
- Before installing a new component, we check that the markings on both valves match and make sure that they are identical.
- Installation and fixation of the product is carried out in the reverse order.
The canister purge valve has been replaced.
How to repair a problem
When talking about repairing the adsorber, the fault should be clearly identified. For example, if we are talking about the Grant adsorber purge valve, the malfunction of which can be indexed by the lack of high-quality gas removal, a new VAZ adsorber purge valve can be a solution to the problem.
The repair of the adsorber valve itself comes down to using a Phillips screwdriver and its application. The procedure for influencing the Lada Granta adsorber sensor:
1) We remove the terminals so that there are no disastrous consequences.
2) Apply physical force and gently remove the valve.
3) We compare the new valve and the old one, because anything can happen in life. Buying an adsorber valve, of course, is a simple thing, but there are mistakes made by sellers/storekeepers who may mistakenly sell an unnecessary spare part.
4) We insert a new valve, assemble this system, return the terminals to their place and enjoy life. The Grant adsorber purge valve, the price of which is almost equally low throughout the Grant sales area, is also a reason for a small, but still joy.
It is impossible in the course of the story about the adsorber not to mention the fact that a huge number of Lada Grant owners prefer to remove this device. There are two reasons for this action:
– lack of desire to repair
– lack of faith in the possible environmental benefits of installing this device in your car
