Carbon adsorber recovery. Canister solenoid valve - where is it used? The principle of operation of the adsorber

About half a year ago, I had to drain gasoline through the fuel pump. Gasoline barely poured, and in the area of ​​\u200b\u200bthe absorber, sniffling-grunting was heard. Opened the cap of the gas tank and gasoline poured out a fountain. I didn’t attach much importance to this, I thought that it should be so.

Since this spring, when you start the engine, it began to smell strongly of gasoline, after a while the smell disappeared. Having climbed and sniffed the car, I did not find any obvious leaks of gasoline.

After reading articles on the Internet, I came to the conclusion that this problem is in the absorber.

But the conditions for checking the operability of the absorber (fuel vapor accumulator), according to the manual, were observed:

A bit of theory.

Why do you need an adsorber in a car. The adsorber is the main element of the fuel vapor recovery system. The fuel vapor recovery system, together with the adsorber, prevents the emission of harmful substances into the atmosphere. The adsorber is filled with coal, which absorbs gasoline vapors.

The scheme given in general is valid for a car of any brand (in funcargo it is a little different). The adsorber is usually located next to the fuel tank (in the funcargo under the hood) and is connected by pipes to the fuel vapor separators (there are none in the funcargo) and to the canister purge valve located in the engine compartment. The canister purge solenoid valve controls the electronic control unit (ECU). Fuel vapors from the tanks are partially condensed in the separator, the condensate is drained back into the tank through the pipeline (this is not the case in funcargo). The remaining vapors pass through the pipeline to the adsorber through a gravity valve installed in the separator. The second fitting of the adsorber is connected by a hose to the adsorber purge valve, and the third - to the atmosphere. When the engine is not running, the second fitting is blocked by a solenoid valve. When the engine is started, the engine control unit begins to supply control pulses to the valve. The valve communicates the adsorber cavity with the atmosphere, and the sorbent is purged: gasoline vapors are discharged through the hose and the throttle assembly into the intake module. Malfunctions of the fuel vapor recovery system entail idle instability, engine shutdown, increased toxicity of exhaust gases and deterioration in driving performance of the vehicle. The units of the fuel vapor recovery system are removed for inspection or replacement if a persistent smell of gasoline appears due to a violation of the tightness of the units and pipelines, as well as as a result of a failure of the canister purge valve. In addition, a violation of the tightness of the adsorber and the failure of the purge valve can cause unstable idling of the engine up to its stop.

Or like this:

This system is designed to trap gasoline vapors in the fuel tank, throttle chamber and intake manifold, thereby preventing them from entering the atmosphere in the form of hydrocarbons. The system consists of a tank with an absorber (activated carbon), pipelines connecting the absorber with a fuel tank, a thermopneumatic valve and a control valve. When the engine is not running, gasoline vapors enter the absorber from the tank and throttle chamber, where they are absorbed. When the engine is started, the tank with the absorber is purged with a stream of air drawn in by the engine, the vapors are carried away by this stream and burnt out in the combustion chamber. The tank is equipped with three ball valves assembled in a single body. Depending on the operating mode of the engine and the pressure in the fuel tank, ball valves connect or disconnect the tank with a thermopneumatic valve (which is connected in series with the throttle chamber).

Normal operation of this device:

When the engine is off, this valve is closed, air with fuel vapors passes through the carbon filter and goes out into the atmosphere, while gasoline vapors accumulate in the coal. Then the engine starts. After some time (or upon reaching a certain speed - depending on the control program), this valve opens, and the engine begins to suck air through the absorber, ventilating it, taking gasoline vapors from activated carbon, as well as the remaining vapors from the fuel tank.

Abnormal operation of this device may manifest itself as follows:

1st reason. The valve is not tight, and the tube connecting the absorber to the atmosphere is clogged (a frequent phenomenon, given that the absorber itself is located in the wheel arch) (in funcargo under the hood). Then, in the heat, gasoline vapors (and there can be a lot of them in a half-empty tank) are etched through the valve into the intake manifold, clogging it and re-enriching the mixture in the first seconds of launch (until the entire intake manifold is pumped). This explains - not a factory from the first, second time, an increase in cases of a non-factory with an incomplete tank, an increase in cases of a non-factory with gasoline that has a low boiling point.

Abnormal operation of this device may also manifest itself as follows:

2nd reason. The valve is tight, and the tube connecting the absorber to the atmosphere is clogged. Then, after standing in the heat, gasoline vapors will accumulate in the fuel tank, increasing the pressure in it (when you unscrew the gas tank cap after parking in the heat, in this case you will hear pshshshsh) (in the funcargo there is a valve in the fuel tank cap that relieves excess pressure, so when this cover, the air should not come out (basically, if the absorber is faulty, it is sucked into the gas tank), and if the air comes out, then the valve in the gas tank cap does not work). On startup, as long as the valve is closed, everything is fine. The car starts and runs for a while until the electronics thinks that the engine is already running quite steadily and it's time to open the absorber valve. And at the moment the absorber valve opens, pressure vapors rush from the gas tank into the air channel, clogging it and re-enriching the mixture. The engine stalls, but when it is started, it works again as if nothing had happened (the pressure in the gas tank is relieved, everything is back to normal).

On more modern machines, error P0441 may be issued. Well, then he pulls P0130, P1123, P0300, P0301, P0302, P0303, P0304, and all sorts of different errors in the operation of oxygenators. The car jerks and stutters. Fuel consumption increased.

Or maybe due to a faulty absorber, a vacuum is created in the gas tank and under certain circumstances the gas tank can “collapse” (shrink), there are descriptions of such cases.

What to do if the absorber is defective?

Buy a new one, expensive from 3500 to 7000 rubles. Delivery from 21 days and not the fact that they will bring. According to the catalog, it gives out the number 77740-52041, but there is nothing for the native number 77704-52040.

Put a contract, but the point is, he practically worked out the prescribed.

Try to disassemble the non-collapsible absorber and replace the insides.

I decided to try to disassemble.
The danger of the event is that if you “don’t give your mind” to the disassembled absorber (that is, you don’t assemble it later), the car will not go. No, well, in principle, you can cut off the top cover, where the valves are, connect and drive like that. I have not tried it myself, but it should work :-).

To begin with (as usual) "prepared".
Asked for advice - no one really knows.
Silence asked in the forum, maybe they didn’t notice, or no one bothered, or “does the car drive, what else is needed” ... I wanted to know in advance that it was funcargo inside the absorber. Maybe someone who has it was broken in order to know what material to prepare for replacement. So no one has...
I read on the Internet, there are several notes, something similar to reports on the repair of the absorber.

Repair of the absorber of the accumulator of gasoline vapors.

The absorber itself is in place.

With top cover removed.

To disassemble it, you need to saw off the bottom of the absorber. But inside there are two springs, which on one side rest against the bottom of the absorber, and on the other against metal plates. Metal plates hold (tamp) the coal inside. In order for the coal not to wake up, first we make cuts from the wide side, then we fix these places with adhesive tape.

We remove springs, plates, filters.

After reading the reports of the "repair" of such absorbers from other car brands, I expected that there would be exactly foam rubber intermediate filters.

My opinion is that this is of course the best option, because. foam rubber turns into dust over time and clogs the absorber valves with this dust and coal, perhaps in this case this dirt can go further along the tubes.

I had to figure out what to make intermediate filters from. But more about that later.

Intermediate filters located in the upper part of the absorber are pressed into the absorber body. I had to cut them out, and clean up the remains with a sharp chisel (you can’t crawl with anything else).

Absorption is the absorption of gases by solids or liquids. In the case of an automotive system, the absorbent is the carbon that the absorber is filled with.

In accordance with environmental standards euro-3, euro-4 and euro-5, harmful hydrocarbon vapors from gasoline fumes must not enter the atmosphere.

To do this, the vehicle's fuel system must be equipped with an absorber.
The fuel system absorber also captures these same vapors.

Car service Trajectory replaces the absorber quickly and efficiently. We do not overcharge for repairs and value our reputation.

Gasoline vapors formed in the tank rise up, and through the hole at the tank neck, they first enter the separator. There they condense and merge back into the tank.
That part of them, which does not have time to turn into condensate, through the gravitational valve through the steam pipeline, they fall directly into the absorber, where they are absorbed by activated carbon.

This happens when the engine is not running.
Otherwise, while the car is moving, when the engine is warm, the control system opens the solenoid valve, and the absorber is purged. Gasoline vapors, together with the air that has entered through another valve, are blown into the engine intake pipe, where they are burned.

Over time, the absorber becomes clogged and may become unusable.

Symptoms of a malfunction of the fuel system absorber can be determined by indirect signs.

One of them is the formation of excess pressure in the fuel tank. This happens due to the formation of vapors that have nowhere to go from the gas tank.

In this case, at the moment of unscrewing the cover, you will hear a hiss.
Therefore, a VAZ, Ford, Renault, Hyundai, Kia, Chevrolet, Toyota, Deo, Mitsubishi, Volkswagen are needed in a car service on Nagorny.

You can buy an absorber in our store.

It seemed such an inconspicuous element, which at first glance, is not important for the car, but without which it cannot work normally. Failures appear, the engine “troit” can even collapse the gas tank! And all this is due to a faulty adsorber valve. Many do not know what it is, how it works and MOST IMPORTANTLY what it affects. Today I will try to put everything in simple words, and also describe the main symptoms of a malfunction. It will definitely be useful, so read - see ...

First, let's start with a definition.

Adsorber (from Latin sorbeo - I absorb) - This is a car system that serves to trap gasoline vapors that come out of the tank. When the engine is running, they are sent to the fuel injection system, namely in. When the engine is turned off, part of the vapors is captured by the separator (it sends them back to the tank), and the remaining vapors enter the adsorber, where they are neutralized.

Why was the adsorber created?

Actually, this is a tribute to the environmental standard, namely EURO-2. In fact, this is a large filter that captures light hydrocarbons. According to the new standards, the ingress of gasoline vapors into the atmosphere is unacceptable, because this contributes to atmospheric pollution.

Also, couples should not go into the car, because it is, to put it mildly, harmful! On old carburetor machines, there was simply no such filter and its valve, the system is slightly different there. BUT the carburetor is gone along with the old standards, now only the injector and the filtration system is MANDATORY.

Components

In fact, this is a large plastic jar, inside there is activated carbon, because it is this composition that perfectly fights gasoline vapors. The main parts can be described as follows:

• Separator + gravity valve
• Pressure meter
• Filter part (usually made of coal)
• Connecting tubes
• Solenoid valve

As you can see, absolutely nothing complicated. Separator - serves to capture part of the gasoline, then sends them back to the tank. gravity valve - almost never used, but it is needed in emergency situations, such as accidents, it prevents fuel from overflowing from the tank (for example, when the car turned over).

Pressure meter , a very necessary thing - it controls the pressure of gasoline vapors inside the tank, if necessary, opens and dumps it, preventing the structure from being damaged.

- as I wrote above, a large jar in which coal powder is poured, in fairly large granules. This is done so that the vapors can freely pass and condense.

Connecting tubes - are needed to connect all the main parts, filters, sensors and valves, I think this is understandable.

Solenoid valve - serves to switch the modes of capturing gasoline vapors, we will talk about it in more detail below.

How the system works - how it works

Why am I focusing on the solenoid valve, because it is practically the key in this system.

For a better understanding, I am laying out a diagram of an injection car, and in this case it is a VAZ of the 10th family.

So, fuel vapor rises up the tank and stops at the separator, which is combined with a gravity sensor (as I wrote above, it prevents fuel from flowing out in case of accidents - capsizing from the tank). In it, they are partially condensed and returned back (in the form of liquid fuel).

However, the other part of the evaporation, bypasses the gravity valve, passes into the adsorber, where they actually accumulate. Accumulation occurs when the engine is not running! IT IS IMPORTANT.

After starting the engine, the solenoid valve opens - thereby connecting the adsorber cavity (where the gases are, as it were, imprisoned) with the intake manifold or throttle assembly (in different machines in different ways). THE PROCESS OF THE SO-CALLED BLOWING BEGINS! The vapors are mixed with air (from the street), which is supplied through the throttle assembly, then enters the intake manifold and then into the engine cylinders, where they are burned with the air-fuel mixture.

The system is very simple if you understand how it works.

What does the adsorber valve affect

Many problems are associated with the adsorber valve. In fact, this is a very simple device that opens or closes under certain conditions (engine running or turned off).

If the valve works well, then there is no problem at all, you may not even know about its presence in your system.

However, when a breakdown occurs, for example, the adsorber cavity itself is clogged, or the valve does not work. That car subsequently, can get serious damage. Because the cavity is not purged, and the pressure from the tank is not relieved.

Symptoms of a malfunctioning adsorber valve

As it becomes clear, there are problems with the power system:

• Floating turnovers. But not immediately, but after about 5 - 10 minutes on a warm engine
• At idle, if the engine is running, you press the gas pedal - it almost stalls. Feels like running out of fuel
• On the move, the car does not develop the necessary power, it seems that 10-15% of the engine power has been removed
• The fuel tank sensor may be going crazy. Shows either “full”, then “empty”, etc.
• If you open the tank for refueling. A strong whistle is heard, as if a vacuum has been created inside.
• Fuel consumption increases
• The absorber sensor can knock hard on a cold one, it is often confused with engine valves

It is also worth noting that the reason is not always in the valve, the can of activated carbon itself (that is, the adsorber cavity itself) can often become clogged. If necessary, it must be replaced or disassembled and cleaned - dried, that is, to restore the filtration of gases so that they pass unhindered.

Now a helpful video.

If you have these malfunctions, then you definitely need to look - and if necessary, change it, since it costs a penny. As well as the cavity itself with activated carbon.

Is it possible to remove

Some motorists neglect environmental standards and remove the canister valve. The words, in principle, are - “yes, why do I need it, the car has become slower, the consumption has become more, I’ll throw it out altogether.” But really, can it be done? Will this make the car worse?

It should be understood that a working system does not affect the operation of the engine at all, and even saves a little fuel, because the vapors that remain in the main body are then burned out in the engine, of course, you should not expect that the savings will be huge, but it turns out several kilometers.

Of course, you can clean the car, it’s simply “ALL RIGHT” to the car! It will even be better, because the evaporation from the tank will not be condensed (cleaned), but will pass directly into the atmosphere. That is, you kind of remove all the cans - valves and give an open air flow to the tank.

Physically, they do it this way - a fine filter from a carburetor VAZ is hung on the hose from the separator, gasoline vapors go into the atmosphere. The hose from the adsorber valve is blocked, the engine is flashed (), otherwise an error will appear, that's all!

However, this also has its downsides:

• For example, the cabin will often smell like gasoline, the fumes will (often) go into it.
• The atmosphere is polluted with light hydrocarbons
• There will be a rack smell of gasoline next to the car (although this is debatable)

Shutdown Pros :

According to the requirements of new environmental standards that limit the content of harmful substances in exhaust gases, vehicles must be equipped with an EVAP system. This equipment prevents harmful fuel fumes from entering the atmosphere. The adsorber performs the main function in the fuel vapor recovery system. Some underestimate the importance of this element in the operation of the car. However, a malfunction of this, at first glance, a minor node can damage the fuel pump and affect the operation of the entire engine. Therefore, experts recommend checking the adsorber valve when there are signs of a motor malfunction.

Absorber valve diagram

The EVAP system is installed on gasoline internal combustion engines to prevent the release of fuel vapors into the atmosphere. The canister purge solenoid valve is an element of this system. Therefore, in order to figure out what an adsorber valve is for and how it works, it is important to understand how the entire system works.
The design of the adsorber is a container filled with an adsorbent, most often activated carbon. The device is connected to the fuel tank and control valve of the car with special tubes.

The canister valve is installed between the intake manifold and the canister and performs the function of ventilation.

Gasoline vapors formed in the fuel tank enter the separator, where they condense and drain back into the tank. Some of the vapor does not have time to condense in the separator and enters the adsorber through the steam line. In the filter system, they are absorbed by activated carbon, accumulated and then fed into the intake manifold when the engine is started.
The process of absorption of fuel vapors takes place only when the engine is turned off. When the car is running, the electronic control unit opens the canister purge solenoid valve, through which air enters and thus ventilation occurs. At the same time, the accumulated condensate, together with air, is sucked out of the adsorber and again enters the engine, where it is afterburned. The canister valve ventilates the entire mechanism and directs fuel condensate back to the engine.

Adsorber valve malfunctions and their elimination

The almost continuous operation of the adsorber of the fuel vapor absorption system can cause damage to the purge valve.
A malfunctioning adsorber valve often leads to damage to the fuel pump. Due to poor ventilation of the canister, gasoline accumulates in the intake manifold, the engine loses power, and fuel consumption gradually increases. This can lead to a complete stop of the engine. The operation of the entire car depends on how the adsorber valve works.

How to check the operation of the canister purge valve?

Checking the absorber valve

In order to notice and correct problems in time, it is necessary to regularly check the adsorber valve. In this case, it is possible to identify a breakdown by certain indirect signs.
When the engine is running at idle or in cold weather, the vapor absorption system makes characteristic sounds, like the canister valve clicks. Some confuse this sound with malfunctions of the timing, rollers or other parts. You can check this by sharply pressing the gas pedal. If the sound has not changed, then it is the adsorber valve that is clicking. Experts can explain what to do if the adsorber valve knocks too hard. To do this, it is necessary to tighten the adjusting screw, while first it is cleaned of epoxy.

The absorber valve can be adjusted.

The screw turns about half a turn. If it is tightened too much, the controller will give an error. Such an adjustment of the adsorber valve will make it work softer and quieter.
However, how to check the adsorber valve for damage?
A broken valve can be determined using the error diagnostic system or a mechanical check.
Electronic error codes are stored in the controller's memory and indicate electrical damage. To check the valve, it is recommended to pay attention to errors generated by the controller, such as "break in the control circuit of the adsorber purge valve."
Signs by which it is possible to mechanically determine the malfunction of the adsorber valve:

1. The appearance of failures at idle speed of the engine.
2. Very low engine thrust.
3. There is no sound of valve operation when the engine is running.
4. A hissing sound when the gas tank cap is opened indicates a vacuum in the system. This is a sure sign of a malfunctioning adsorber ventilation.
5. The appearance of the smell of fuel in the car. However, there may be other reasons for its appearance.

Do-it-yourself absorber valve replacement

Absorber valve

If signs of malfunction are found, repair or replacement of the valve is required. The canister valve is inexpensive and easy to replace. For dismantling, you need to have a pair of Phillips screwdrivers and know where the canister purge valve is located.
Operating procedure:

Markings of the old and new valve must match.

1. Open the hood and find a cylindrical device - an adsorber.
2. Remove the negative terminal from the battery.
3. Disconnect the wiring harness by pressing the latch and pulling towards you.
4. Loosen the valve mount.
5. Remove the fittings under the latch and disconnect the hoses.
6. Remove the valve together with the bracket from the adsorber.
7. The new valve is installed in the reverse order.

Thus, even such a small element as an adsorber valve performs important functions and its malfunction can seriously disrupt the operation of the entire engine. Therefore, it is important to monitor the condition of your car and carry out diagnostics in time.

Let's consider in simple terms how the adsorber works on a car, what kind of adsorber malfunctions can be, and also how easy it is to check the adsorber valve.

Many motorists do not know at all what an adsorber is and, even more so, why it is needed and whether it is installed on their car. Also, most underestimate this node and consider it secondary in the car device.

Misconceptions are also found in understanding the principle of operation of the adsorber purge valve.

Adsorber operation

I will try to briefly and clearly explain the principle of operation of the adsorber and the purge valve. This node is poorly described on the Internet and erroneous opinions on the principle of its operation are very common.

The adsorber is primarily designed to reduce environmental pollution with gasoline vapors. Everyone knows that gasoline evaporates very well. So, on cars without an adsorber, gasoline evaporates into the atmosphere, and on cars with an adsorber, these vapors are burned in the engine cylinders.

The principle of operation of the adsorber on different cars is the same, the only difference is in the shape and location of the adsorber and the purge valve. For some, it is installed in the engine compartment, and, for example, for the Lacetti, under the bottom near the rear wheel, and the purge valve is in the engine compartment.

Fuel vapors from the tank enter the adsorber (a container with activated carbon) through the fitting marked "TANK", where they accumulate while the engine is not running. The second canister fitting with the inscription "PURGE" is connected by a tube to the canister purge valve, and the third one with the inscription "AIR" is connected to the atmosphere.

1 - vent fitting AIR, 2 - fitting TANK of the pipe for supplying fuel vapor from the tank to the adsorber, 3 - fitting PURGE of the pipe for removing fuel vapor from the adsorber to the valve

When the engine is stopped, the purge solenoid valve is closed, in which case the adsorber does not communicate with the intake manifold.

When the engine is running, the electronic unit, controlling the solenoid valve, purges the adsorber with fresh air due to rarefaction in the intake manifold. That is, the vapors are sucked out of the adsorber.

Gasoline vapors are mixed with air and discharged into the intake manifold by the throttle and then enter the engine cylinders.

The principle of operation of the adsorber

Many mistakenly believe that when the engine is started, voltage is immediately applied to the adsorber valve and it opens, purging the adsorber. I even saw “guides” and “training videos” about this. In fact, the purge valve is controlled by the ECU according to special algorithms based on the readings of temperature sensors, air flow, etc.

The greater the air consumption of the engine, the longer the duration of the control pulses of the ECU and the more intense the purge.

It is impulses, and not just voltage supply! Therefore, there is such a thing as “adsorber purge duty cycle”, which ranges from 0% to 100%.

Here is the adsorber purge duty cycle in the Chevrolet Explorer diagnostic program. For the entire trip, this is only the first ECU signal to purge, equal to only 6%. So this is a complex and important process in the operation of the engine.

Adsorber malfunctions

Cases of engine malfunctions due to the fault of the adsorber valve occur and they pay attention to it only when there is nothing else to change

Therefore, diagnosing and checking the performance of the adsorber purge valve is very important. Moreover, it is very simple and does not require any supernatural knowledge.

adsorber valve. How to check it

The principle of verification on most cars is the same, but we will look at the example of the Chevrolet Lacetti.

Problems with the canister purge valve can be divided into several main points:

• no impulses coming to the valve
• valve coil failure
• valve stuck open
• valve sticking in the closed position

It is very simple to check the pulses, wiring and winding of the valve, in the tab “mechanism control - test the adsorber purge valve”. When you click on the "ON" button in the program diagram, we will see the following signals

This means that the ECU is giving a command to the valve. Along with this, the sound of clicks will come from the valve in time with these signals, which, in turn, means that the pulses reach the valve and the winding is intact, since the valve is triggered.

By the way, if you don’t have a diagnostic adapter yet, then I advise you to read and.

The electrical part is correct. We checked this. But to be sure that the valve is not physically stuck, it can be removed and checked. It is dismantled very easily and it takes me no more than 30 seconds.

Two tubes and a block with two wires are connected to the valve. The valve itself is not even screwed, but simply inserted into its workplace.

In the photo, one tube has already been removed.

To remove the valve, it is enough to pull off the two tubes marked with a green and a red arrow (the red one has already been removed, and the green one is hard to see from this angle). The tubes are removed simply and easily without any clamps.

Then press the metal latch and unfasten the wire block (shown by the yellow arrow)

After that, press on the fitting shown by the red arrow and the valve will come out of its seat

The valve is normally closed, i.e. without voltage it does not let air through. You need to check this in any way possible - with a rubber bulb, an inflatable ball, etc.

I had a syringe and a piece of a vacuum tube left after .

When moving the syringe plunger, resistance should be felt, and the plunger itself tends to return to its original position, which means the valve is sealed. When removing the tube from the syringe, a characteristic puff should be heard. This means that the adsorber valve is closed hermetically.

It remains to check only the opening of the valve. To do this, we take two wires with such mini-mothers

And connect to the adsorber valve connector. You can neatly and simply wire without a tip.

We move the syringe plunger and connect the wires to the battery. When connected, the same zilch should be heard, which means that the valve has opened and relieved pressure.

It happens that the valve does not open. Then just change it to the correct one.

That's all the simple methods on how to check the adsorber valve.

Peace and smooth roads to all!!!

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