Do-it-yourself absorber repair Passat

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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 main function in the fuel vapor recovery system is performed by an adsorber. Some people underestimate the importance of this element in a car's performance. However, a malfunction of this, at first glance, a minor unit can damage the fuel pump and affect the operation of the entire engine. Therefore, experts recommend checking the adsorber valve when signs of engine malfunction appear.

The EVAP system is installed on gasoline internal combustion engines to prevent fuel vapors from entering the atmosphere. The canister purge solenoid valve is part of this system. Therefore, in order to find out what the adsorber valve is for and how it works, it is important to understand the principle of the entire system.
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 the control valve of the vehicle with special pipes.

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

Gasoline vapors generated in the fuel tank enter the separator, where they condense and are drained back into the tank. Some part of the vapors 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, accumulate and then, when the engine is started, are fed into the intake manifold.
The absorption of fuel vapors takes place only when the engine is off. When the car is running, the electronic control unit opens the canister purge solenoid valve, through which air enters and thus ventilation occurs. In this case, the accumulated condensate, together with the air, is sucked out of the adsorber and again enters the engine, where it is burned out. The canister valve provides ventilation for the entire mechanism and directs the fuel condensate back to the engine.

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

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 idling or in cold weather, the vapor absorption system emits characteristic sounds, as the adsorber valve clicks. Some people confuse this sound with a faulty timing belt, rollers or other parts. You can check this by sharply pressing the gas pedal. If the sound has not changed, it means that the valve of the adsorber is clicking. Experts can explain what to do if the canister valve knocks too hard.To do this, you need to tighten the adjusting screw, while first it is cleaned of epoxy resin.

The absorber valve can be adjusted.

The screw turns approximately half a turn. If you tighten it too much, the controller will generate an error. Such an adjustment of the adsorber valve will make its operation softer and the knocking quieter.
However, how to check the canister valve for breakage?
Valve breakage can be determined using an error diagnosis 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 such errors generated by the controller as “open circuit of the adsorber purge valve control circuit”.
Signs by which it is possible to mechanically determine the malfunction of the adsorber valve:

1. The appearance of dips at idle speed of the engine.
2. Very low engine thrust.
3. No valve actuation sounds are heard when the engine is running.
4. A hiss when opening the gas tank cap indicates a vacuum in the system. This is a sure sign of a malfunctioning adsorber ventilation.
5. The smell of fuel in the vehicle interior. However, other reasons can cause its appearance.

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

The 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 storage battery.
3. Disconnect the connector by pushing in the lock and pulling it towards you.
4. Loosen the valve fastening.
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 failure can seriously disrupt the operation of the entire engine. Therefore, it is important to monitor the condition of your car and carry out diagnostics on time.

Damage to the device that controls the operation of the gasoline vapor recovery system usually leads to a slight increase in consumption and a small loss of power. At the same time, prompt replacement of the adsorber valve avoids a number of much more serious problems. Due to a violation of ventilation, a vacuum is formed in the tank, which causes an increase in the load on the fuel pump and can lead to the failure of the latter.

With the engine off, the canister purge solenoid valve should be closed. After starting the engine, the control system gives the command to open it, and the air, passing through the EVAP system, is saturated with fuel vapor and enters the intake manifold. Together with the combustible mixture, it enters the cylinder and burns there.

The electromagnetic device has a winding and an actuator that allows the channel to be closed or opened. The reasons for the failure of the valve through which the adsorber is purged may be as follows:

• Burnout of wiring or interturn short circuit.
• Damage to the control circuit.
• Significant depletion of the valve working surface and seat surface.
• Violation of tightness due to the ingress of sufficiently large mechanical particles into the chamber.

Diagnostics of the EVAP system involves the use of motor testers, with which the error code is determined. The exact cause of the failure of the valve designed to purge the adsorber is established during the checks of the electrical circuits. For these purposes, a digital or pointer tester with a mode for determining the resistance of the windings is used. A significant deviation from the passport data indicates a winding break.Fault detection of the actuator is impossible due to the fact that the device has a non-separable housing.

After detecting a failure of the electromagnetic device, it will need to be replaced. Due to the design features, repair of the adsorber valve is not performed, an attempt to restore its operability will lead to its destruction and does not make sense. For the same reason, high-quality cleaning of the contaminated unit is impossible. The valve, if necessary, is washed with a solvent and blown out, if a defect remains in its place, a new one is installed.

To eliminate the malfunction, it is necessary to remove the product in the following order:

• Disconnect the electrical connector.
• Loosen the clamp screws with a screwdriver and remove both tubes.
• Remove the bolt securing the valve to the vehicle or engine body.

The installation of a new electromagnetic assembly is carried out in the reverse order, before the connector is docked, a small amount of non-conductive grease is applied to the contact surfaces. This will ensure their reliable protection against corrosion and ease of separation.

The installation of a new unit does not present any particular difficulties for a person with minimal skills in working with a locksmith's tool, especially since it does not require adjustment. The main problem is diagnosing the causes of valve failure, this will require a motor tester and an experienced technician. When decoding fault codes, errors are possible, in addition to the failure of the indicated unit, clogging or damage to the adsorber is likely.

A visit to a car service with modern equipment allows you to quickly eliminate a malfunction of the EVAP system valve. A qualified technician using electronic devices will quickly and accurately determine the cause of the failure and replace the damaged unit.

Actually, I will try to raise this question, since in the search (I searched it up and down) I did not find specific answers. It seems that they tried to discuss this topic several times, but they did not bring it to its logical conclusion.
Attention question: Has anyone removed the absorber from the American, if so, what are the pitfalls and how complicated the procedure itself is.

Well, no one knows, I was the first to decide by such a thing for

fool around?

100% impossible. I've been. At first I got sick of cutting it. Then he got bored of washing the coal off the balcony.
2 rubles is being analyzed. Quite a worker. I have been skating with this for almost 2 years.

we have 750

not everyone will enter

but the essence of the process is clearly communicated

He is the head, and the head is not offended by jokes, even by vulgar ones.

Once upon a time there were smart guys in the subject. Kalex, Avas, the terminator. but they are already driving other cars. Dima is one of the last to appear in the topic. Dokhtur also gives useful advice. It's easy to offend a person. Only after that you should not expect gratitude from him in the form of useful advice. Also gta-2, Seryoshka (Komsernik) willingly help. but then there were garage craftsmen and shit in the subject. More flood (mossy) than good.
This is sad.
More and more newcomers appear in the subject, who, out of the modesty of the family budget, buy the killed B5 from the former owners. Killed by their hands.
There are two options. If you want to help, help with practical advice. If you want to cheer, you are on your way to the smoking room-swear word. Nothing to say - better keep silent. See what SMART people write.

fibonathi, This does not apply to you. You are up to date and your advice is helpful.
And I love jokes too. But not vulgar.

Somewhere half a year ago I had to drain gas through a gas pump. Gasoline was barely pouring, and in the area of ​​the absorber there was a sniffing grunt. I opened the lid of the gas tank and gasoline poured out in a fountain. I did not 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 passed. Climbing around and sniffing the car, I did not find any obvious gasoline leaks.

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:

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 harmful substances from being released into the atmosphere. The adsorber is filled with coal, which absorbs gasoline vapors.

This system is designed to trap gasoline vapors in the fuel tank, throttle chamber and intake manifold, thereby preventing them from entering the atmosphere as hydrocarbons. The system consists of a tank with an absorber (activated carbon), pipelines connecting the absorber to the fuel tank, a thermo-pneumatic 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 reservoir with the absorber is blown through by the air flow sucked in by the engine, the vapors are carried away by this flow and are burned 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 thermo-pneumatic valve (which is connected in series with the throttle chamber).

Normal operation of this device:

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

Abnormal operation of this device may manifest itself as follows:

1st reason. The valve is not tight, and the pipe connecting the absorber to the atmosphere is clogged (a frequent phenomenon, given that the absorber itself is located in the wheel arch) (in the 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 starting (until the entire intake manifold is pumped). This explains - not a plant from the first, second time, more frequent cases of not a factory with an incomplete tank, more frequent cases of not a factory with gasoline having a low boiling point.

Abnormal operation of this device can also manifest itself like this:

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 funcargo there is a valve in the fuel tank cap that relieves excess pressure, so when unscrewing air should not come out of this cover (mainly, if the absorber is faulty, it is sucked into the gas tank), and if air comes out, then the valve in the gas tank cover does not work). At startup, as long as the valve is closed, everything is normal. The car starts up and runs for some time until the electronics thinks that the engine is already working steadily and it’s time to open the absorber valve. And at the moment of opening the absorber valve, vapors under pressure rush from the gas tank into the air channel, clogging it and re-enriching the mixture. The engine stalls, but when started, it works again, as if nothing had happened (the pressure in the gas tank was dropped, everything returned 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 on the work of oxygenators. The car twitches and dulls. Fuel consumption increased.

Or it may be that 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 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 nothing on the native number 77704-52040.

Deliver a contract, but the point is, he practically worked out what he was supposed to do.

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 cannot assemble it later), the car will not run. No, well, in principle, you can cut off the top cover, where the valves are, connect and drive like that. I haven't tried it myself, but it should work :-).

To begin with (as usual) "prepared".
I asked for advice - no one really knows.
Asked in the forum "Urgent to the room" SOS. as well as “one-off” questions! silence, maybe they didn’t notice, or no one bothered, or “but the car drives, what else is needed” ... I wanted to know in advance what was inside the absorber exactly funcargo. Maybe someone who has it was broken to know what kind of replacement material to cook. So no one has ...
I read it on the Internet, there are several notes that are similar to the repair reports of the absorber.

Repair of the gasoline vapor accumulator absorber.

The absorber itself is in place.

With the 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 abut against the bottom of the absorber, and on the other against metal plates. Metal plates hold (compact) the coal inside. In order to prevent the coal from spilling out, first we make cuts from the wide side, then we fix these places with tape.

Then we file the remaining parts. We saw only along the edge with a depth of about 10 mm. Cutting through should not be done because the springs can be damaged.

Sawed off. Turn it upside down, remove the tape.

We remove springs, plates, filters.

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

As it turned out, the white spacers in the photo, hereinafter I will call them intermediate filters, both upper and lower, between the coal are not foam.

My opinion is that this is certainly the best option, because The 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 pipes.

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

Intermediate filters located in the upper part of the absorber are pressed into the absorber housing. I had to cut them out, and clean up the remnants with a sharp chisel (nothing else can crawl up).

I am not a guru, but I will try to answer (I work in a service with auto electronics for a long time). The adsorber ventilation valve is an electro-mechanical device connected to the air access line to the throttle space. It is switched on at certain engine operating modes by impulses from the Engine Control Unit, sucking air together with gasoline vapors from the fuel tank.
To diagnose its replacement, it is necessary to carry out computer diagnostics, check its operability “manually” (by opening it with a computer, check whether air passes freely through it).
If it fails, then the first sign is the absence of a sound of air sucking into the fuel tank when opening the gas tank cap before refueling. Everything else is necessary special equipment.
I do not recommend rushing with the replacement.

There is the following problem, which I have been struggling with for some time and not only me, in general, the problem is popular for the Americans and not only the trade winds, so the course of events is as follows:
I’m driving one morning with half the tank and the message about an unclosed tank and a pictorgam on the tidy lights up, I stop, turn off, check the tank - everything is fine, I start it, the food burns further to the destination, I put the car on for several hours. the pictogram goes out, I'm going home.
the next day everything is repeated. but in the evening, when I was driving home, the check caught fire.
I read errors - P0442 - a small leak in the fuel tank ventilation system.
I climb into no - the main reasons are the gas tank cap and the adsorber purge valve. I change the valve - it didn't help, I disassemble the lid - everything is fine there, I change the rubber band - it doesn't help.
I fill in a full tank - errors do not appear until 1/2 of the tank, then everything is in the same sequence, but it is natural that only for a cold car and the less fuel in the tank, the more likely and more frequent errors.
the problem progresses a little and already the first message about an unclosed tank appears on 3/4 of the tank and, together with P0442, error P0445 appears - a large leak is detected.
Where to dig next?

Posted at 10:24, previous message was at 10:22

Post added at 10:26, previous post was at 10:24

so far, I don't see anything else how to change the absorber ($ 350) or separately the V144 diagnostic pump with filter ($ 180). maybe someone will have bright thoughts or experience on this part.

fresh thoughts about the operation of the system appeared, a diagnostic pump is said everywhere, but it’s not a nichrome pump and the tightness check does not take place through excessive pressure, but through the creation of a vacuum, i.e. the principle of operation is as follows:

I assumed for a long time - 90% of the problem can be defeated by replacing only the "diagnostic pump" separately, or try to repair or modernize it (it is unlikely to amputate completely, IMHO, because a very cunning bastard (I tried to squeeze the tubes - he starts to swear at a malfunction.), but we need to think more (pictures of the insides would help. and if he was a non-working reptile for bullying.). maybe the membranes and valves do not create tightness, or the seals are dry or dirty, the springs are weak, the stem may be jammed or has a depletion along which the suction is going on, maybe it’s in the control solenoid and its contacts and try to disassemble it, but a corpse is needed for preliminary experiments.the necessary vacuum is not created or is created but does not hold.but.with a cold snap, the error may appear less often or disappear until the next warming or summer, i.e. also it is somehow connected with temperature, but then the tightness is not in business, because with warming, the membranes and valves become elastic her and denser. and if we take into account that there is a dependence with the fullness of the tank, then the tank is also somehow tied sideways. plus there is still a moment - an error and an indicator of an unclosed tank appear at the moment of an increasing load.

According to the European standard, the emission of vapors from the fuel tank into the atmosphere is prohibited. To comply with the conditions, a mechanism for afterburning gasoline vapors in the engine was developed.

The adsorption element is connected to the gas tank and the throttle pipe. Activated carbon is used to retain fuel vapors. It absorbs vapors from the fuel system even when the engine is not running, and the movement of air in a running engine sucks vapors into the combustion chambers.

The fuel vapor recovery mechanism responds to the switching of the solenoid valve controlled by the ECU (electronic engine control unit).

The system is robust and simple, but there are a few things to keep in mind. The adsorber is made of plastic, visually similar to a thermos. At the top there are branch pipes for connection with the system hoses, and at the bottom there is a tube with a hole for air suction.

The biggest inconvenience is that the unit is installed at the front wheel, at the level of the bumper. Bad choice for our roads and climate.

In rainy weather, the air nozzle can "sip" water, the coal will get wet and freeze.Tank ventilation will be disrupted, gasoline supply will become uneven, the engine will run unstable, stall.

It is better to replace the adsorber. As you can see from the title, we will change to the Volkswagen Passat B3. Some craftsmen cut the plastic casing, pour out the activated carbon, take out the filter and dry it all. Then assemble and glue or solder the body. Meanwhile, the new adsorber costs $ 10.

So, having removed the air filter box, you can gain access to the upper part of the adsorber with hoses and fasteners.

Sometimes it happens to find a completely dilapidated mount that requires replacement. It is difficult to find the original, but you can cut out some kind of galvanized sheet. There are practically no difficulties. Care is required with hoses.

The new adsorber for the Volkswagen Passat B3, like many other cars, must be positioned so that the intake manifold is directed away from the wheel. Otherwise, the inlet will quickly become clogged with dirt.

In the old days, the air suction tube came out vertically downward. A hose was pulled over it and taken out into the engine compartment. The problem of water and mud access was solved. Now the branch pipe is located horizontally, moreover, it has become wider. It is difficult to find the right hose. Therefore, you must follow the direction of the nozzle.

Engine malfunctions are not the only nuisance when the adsorber is not working. Difficulties can arise with the fuel tank, but that's a different story.

Adsorber. What is it in the car, what is it for, what it affects and what are the main symptoms of a malfunction

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

THE CONTENT OF THE ARTICLE

Let's start with a definition.

Adsorber (from Latin sorbeo - absorb) Is a vehicle system that is used to trap gasoline vapors that come out of the tank. With the engine running, they are directed to the fuel injection system, namely intake manifold... 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.

Actually, this is a tribute to the environmental standard, namely EURO-2. It is essentially a large filter that captures light hydrocarbons. According to the new standards, it is unacceptable for gasoline vapors to enter the atmosphere, because this contributes to atmospheric pollution.

Also, couples should not enter the car, because this is harmful to say the least! On old carburetor cars, there was simply no such filter and its valve, the system there is a little different. BUT the carburetor is gone along with the old standards, now only an injector and a filtration system MANDATORY.

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

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

As you can see, there is absolutely nothing complicated. Separator - serves to catch some of the gasoline, then sends them back to the tank. Gravity valve - almost never used, however, it is needed in emergency situations, for example, in case of accidents, it prevents fuel overflow from the tank (for example, when the car overturned).

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

Filtering part - as I wrote from above, a large can, in which coal powder is poured, in rather large granules. This is done so that vapors can pass through and condense freely.

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.

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 vapors rise up the tank and stop at the separator, which is combined with the gravity sensor (as I wrote above, it prevents fuel from leaking out in accidents - overturning from the tank). In it, they partially condense and return back (in the form of liquid fuel).

However, another part of the evaporation, bypassing the gravitational 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 it connects the adsorber cavity (where the gases are, as it were, in a confinement) with the intake manifold or throttle assembly (in different cars in different ways). THE PROCESS OF THE SO CALLED PURGE BEGINS! The vapors are mixed with air (from the street), which is supplied through the throttle unit, then enters the intake manifold and then into the engine cylinders, where they are burned out with the air-fuel mixture.

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

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

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

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

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

• The revolutions are floating. 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 you're running out of fuel
• On the move, the car does not develop the required power, it feels like they removed 10-15% of the engine power
• The fuel tank sensor can go crazy. Indicates that - "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
• On a cold, the absorber sensor can knock violently, it is often confused with engine valves

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