EGR is a system that reduces the temperature in the fuel combustion compartment. The EGR sensor reacts to an increase in temperature, as a result of which the system begins to work.
When the sensors are triggered, the valve begins to open, which adds to the air of the exhaust gas.
This measure reduces the temperature in the combustion chamber, so that the engine will not overheat, because it is overheating not only increases the intensity of the wear of parts, but also increases the likelihood of explosion and fire.
EGR system
Exhaust Gas Recirculation is a system of recycling previously used air. The main purpose of this system is to reduce emissions of nitrogenous oxides.
The system is installed on both gasoline and diesel engines internal combustion. In the case of engines that function on gasoline, the pump losses decrease, and the risk of fire and explosion is reduced.
And in the case of diesel engines EGR their work becomes more "soft", and also decreases fuel consumption.
The idea of \u200b\u200bthe work of this system is that with certain modes of operation of the motor part of the already spent exhaust gases It will be supplied to the hole where the air enters, from the collector, through which the gas leaves the system.
The fact is that the excessive content of toxic compounds in waste operation of diesel or gasoline engines is caused by a high temperature in the combustion chamber. The catalyst for the combustion reaction is oxygen, Accordingly, the greater this element, the higher the temperature.
When feeding the combustion of exhaust exhaust in the combustion chamber, the oxygen content decreases significantly, as a result of which the temperature decreases.
In addition to mixing exhaust gases makes it possible to reduce the toxicity of exhaust gasesWhat positively affects the environment, as well as ensure the continuous operation of the engine.
For the first time, the exhaust gas recirculation system was installed on Chrysler cars, which came with the convo in 1972.. The first experience of using this system was not worthy, since the design was not perfect, as a result of which she did not receive distribution.
In that system through the inlet tube, which was below the carburetor, exhaust gases were supplied, which then came through a special hole in the mixture, air and fuel.
All imperfections of this design were manifested in the fact that the exhaust came to the cylinders for any modes on which the motor is capable of working, as a result of which the process of heating the cold engine, and the power was lost during the load, which in turn led to the overflow of fuel.
However, at the same time in 1972, only on the car of another brand, Buick, another pneumatic was used. mechanical system EGR. If you compare it from the first, it was more successful, so much used to this day.
It is worth noting that the EGR system gives a lot of trouble to the owners of cars, since quite capricious (especially if the car is refueling in improper quality). The fact is that exhausts in addition to carbon dioxide contain particles of soot, which settles on the elements of the system, as a result of which the engine work is asplatated.
It must be said that the repair of the EGR system is expensive due to the valve. So many owners instead of repair prefer to join the entire EGR system.
The principle of operation egr.
The idea is to mix some part of exhaust gases to the air mass located in the intake manifold. Where the high content of nitrogen oxide causes an increase in temperature in the combustion chamber.
As is known, combustion is possible only in the presence of oxygen. The exhaust gases that were previously mixed with air reduce the content of this element.
In this way the temperature in the fuel combustion chamber is reducedIt has a beneficial effect on the state of the system, and also reduces the toxicity of the exhaust and fuel consumption.
The EGR system of the EGR system Exhaust Gas Recirculation includes:
- The main part is the EGR valve. This element provides the movement of gases from the exhaust in the entry opening of the engine. Since the valve is constantly in contact with the hot gases, it has the smallest duration of operation, rather than other components of EGR.
The basic malfunction of the valve, it is the main reason for the breakdown of the entire system, is the lack of tightness.
In the varieties of the EGR system, the coordination of operation can be carried out, both with the help of electrical signals and using a pneumatic system. The last type of control is the most common.
- Colenenoid Egrr.. Used in systems that have pneumatic valve control.
The main malfunction is exactly the same as in the case of a valve, namely leakage. The malfunction of the EGR solenoid affects the operation of the engine exactly as in the event of a valve breakdown, the system loses hermeticity and exhaust gas leaks are possible, as a result of which further operation becomes unsafe.
- EGR valve valve position change sensorAlso called the degree of discovery degree of the system valve.
There are situations where this element fails, but in this case, in addition to the tanned engine malfunction lamp, there are no other unpleasant and even more so hazardous consequences.
- Control unit internal combustion engine. Various systems may have a different set of components, but the EGR valve is in absolutely all.
It is from this element that the entire EGR system, but also the engine depends largely. On some internal combustion engines, working together with the system, EGR applies additional measures to cool gas cooling.
To do this, this node enters the engine cooling system. Such a measure allows you to further reduce the level of emission of nitrogen oxides. How the EGR system works in many respects is determined by the type of internal combustion engine.
In engines running on diesel fuelThe opening of the valve occurs at idle, which provides up to half air on the inlet.
With an increase in the number of revolutions, proportional closing of the valve occurs, up to the fact that it closes completely at maximum load. During engine warming, the valve is also completely closed.
In the case of engines that operate on gasoline, the system does not work at idle, and also does not turn on at the largest rev..
Works with medium or low load, providing from 5 to 10 percent of air supplied to the system.
Two types of control systems:
- electric;
- pneumatic.
The most common second.
EGR system action with pneumatic control as follows: ·
- With the appearance of vacuum discharge in the combustion chamber, the diaphragm rushes upwards As a result, the spring effort is overcome, which presses the damper. Thus, the valve opens and the exhaust goes into the chamber.
- After reducing the temperature in the chamber, the discharge in it also decreases, with the result that the valve closes under the action of the spring. In the case of electrical control there is a sensor that responds the discharge status and gives a signal to open the valve. When a decrease in the level of discharge, and hence the temperature, respectively, the closure occurs.
EGR system malfunctions
Problems in the operation of the exhaust gas recirculation system, as mentioned above, arise as a result of deposits accumulations in the nest or plate plate, the main element of the system.
NAGA is often due to the use of inadequate quality fuel, as well as violations of the functioning of the ventilation system of the crankcase and nutrition, the wear of the details of the cylindroport group, malfunction in the operation of the turbocharger, problems in the operation of the sensors, which are responsible for managing the operation of the entire EGR system.
The valve clogging can lead or to the wedge, or to the slow motion system.You must turn off, remove, then clean.
The encoding may well occur both during opening and during the complete closure of the valve flap.
When the result, during the opening, the result may be an unstable operation of the motor, when operating a motor on gasoline, and in the case of a diesel engine there is a reduction in power.
In the event that the encoding happened during the closure, the gasoline engine will consume more fuel, but the engine running on diesel fuel will work more "hard".
The slowdown in the opening of the valve does not lead to consequences, more often the malfunction is reflected at work at idle.
Exhaust gas recirculation system (EGR). Device. Fault.
The exhaust gas recirculation system (EGR) reduces nitrogen oxide emissions (NOX). At high temperature, a large amount of nitrogen oxides (NOx) is formed in the combustion chamber of the combustion chamber of the fuel-air mixture. The recycling system sends a part of the exhaust gases from the exhaust channel of the cylinder head through the intake manifold in the combustion chamber, thereby reducing the combustion temperature of the fuel and air mixture, as a result of which the concentration of nitrogen oxides occurs.
The idea is to serve some part of the exhaust gases from the exhaust manifold in certain modes of the engine. Increased content of nitrogen oxides in DVS emissions is caused by high temperature in the combustion chamber. The combustion reaction catalyst is oxygen: the more oxygen - the higher the temperature. And if you mix exhaust gases to the air, the oxygen content will decrease in it. As a result, the combustion temperature of the mixture and, accordingly, the toxicity of exhaust gases is reduced.
EGR is installed on gasoline (except for turbine) and diesel engines. Due to the excess of air, a larger amount of nitrogen oxides is formed in the diesel. In addition to improving environmental indicators (NOX emission is reduced to 50%), there are still some "side" positive consequences. In gasoline engines, the portion of exhaust gases, reducing the discharge in the intake manifold, reduces the pumping losses, which helps reduce the fuel consumption by 2-3%. Work under reduced temperature in gasoline engines Reduces the risk of detonation, and the operation of diesel engines is becoming softer. Sawing in diesel engines with the EGR system decreases by 10%.
The EGR operation algorithm depends on the type of engine. In diesel engines, the valve opens at idle and supplies up to 50% of the air volume on the inlet. With increasing revolutions, the valve is proportionally closed until complete closure at the maximum load. When warming the motor, the valve is also completely closed. In gasoline engines, EGR does not turn on on a cold engine, idling and on the turnover of the maximum torque. With low and medium load, the system provides 5-10% of the air supplied.
It is worth noting that EGR is often becoming a headache for our motorists. The system is quite capricious, when it is work (especially on domestic fuel), the EGR valve, the intake manifold and the sensors in it are covered by nagar, which leads to unstable engine operation. EGR valve is a detail expensive, so many car owners instead of its replacement resort to the joy of the entire system.
And why EGR is not installed on gasoline turbo engines? On atmospheric engines, the system works almost only on medium turnover. And on turbocharging motors, the working range is even less - and it turns out that the goal does not justify the means. Therefore, manufacturers apply other methods for reducing NOx emissions: liquid cooled air conditioning (which reduces the temperature in the combustion chamber) and the stepless system of changing the phase distribution (providing the internal recycling of exhaust gases). With internal recycling, part of the exhaust gases falls back to the cylinder at the moments of the valve overlap, when both intake and intake and exhaust valve. Technically, the overlapping can be organized and using the selection of camshaft camshaft shape, but in this case recycling will be carried out on all modes of engine operation. In the systems of stepless regulation, the overlap of the valves over the command of the control unit occurs only in the required modes.
Types of structures
Although the principle of operation of all systems is the same, their constructive execution is characterized by a large variety. In any EGR system, the main part is the valve. The differences consist in the method of managing its work and, accordingly, the composition of the elements. For the first time, EGR appeared on american cars Even at the beginning of the 70s of the last century. They were pneumomechanical, that is, managed only by the discharge of the intake manifold.
Like any mechanical system, it did not differ in high accuracy of work. With the introduction of electronic EGR engine control systems with electropneumatic (EURO-2 and -3), and in the future, and completely electronic (EURO-4 and -5) appeared.
The EGR valve can be installed on an intake manifold, in a suction path, or directly on the throttle block. Since in diesel engines, the EGR system connects more exhaust gases, then the valves in such systems have a torque hole of the larger diameter compared to gasoline. In some diesels, especially turbocharged, inlet pressure may exceed the pressure on the release, which makes it impossible to recycle exhaust gases. In such cases, regulating (vortex) dampers are installed to create a necessary reduced pressure in the inlet pipeline.
EGR main faults
In case of malfunction of the EGR system, unstable revolutions may be observed. idle move And the engine often stalls. There is also an unstable job with a fully open throttle, interruptions when reducing revolutions, detonation, ignition skipping.
All faults are reduced to two main reasons:
- Through the EGR valve passes an insufficient number of exhaust gases.
- Through the EGR valve, too many exhaust gases pass.
External nozzles (or channels in the intake collet) for the supply of exhaust gases.
Actually Valve EGR.
The thermoclasp that connects the sprinkler to the EGR PANA depending on the temperature of the coolant or air.
Solenoids, electrical or digital valves, controlled by the ECU.
Integrated or individual exhaust gas pressure transducers.
When channel contamination, the recycling flow decreases, pollution increases ambient nitrogen oxides N0x. Since the driving characteristics are almost not changed, the drivers are rare on such a malfunction. Sometimes detonation can occur and the engine benefit is deteriorating (the computer is not included in the closed mode).
Also manifests itself and not opening valve EGR. The valve design involves locking it when faults in the EGR system.
Solid particles from exhaust gases are settled unevenly in the EGR valve locking device and gradually the NEpets valve is tightly closed. In this case, the recycling of exhaust gases begins to occur continuously. This situation will be reflected in the stream of parameters taken by the scanner from the ECU, but for final outputs about the status of the valve should be disassembled. After cleaning and before installing the valve, make sure that the freedom channels from the plots of deposits that can re-clog the system.
The unlucky valve usually manifests itself as follows:
- Instability idling, frequent engine stop, ignition skipping.
- Car jerk when driving.
- Reducing the vacuum in the intake manifold and the consequence of work injector Engine On a rich TV mixture.
In the operating instructions, it is recommended to carry out a regular inspection and cleaning of the valve and channels of the EGR system. But drivers usually neglected by this, until the system fails.
Rolling signal out
A weak or missing permit signal will not open the pneumatic valve, and the permanent vacuum will support the valve open all the time. In such cases, you should check the correctness of the connection of vacuum hoses and the vacuum on the valve.
In systems using a vacuum amplifier, a vacuum amplifier is used, a malfunction of which can lead to a disconnection of the vacuum signal from the EGR valve or vice versa to its constant feed.
The operating EGR system is turned off when the engine is heated by the thermoclap perm. The thermoclap malfunction will lead to excessive environmental pollution of nitrogen oxides (if the thermal flaps is constantly closed) or the unstable operation of the engine at idle turns and insufficient pickup (if the thermoclap is always open).
In some systems, the EGR valve opens by the joint action of the resolution and pressure of exhaust, gases. In such systems, even with good permission, the EGR valve will not appear if some of the output channel components have been changed to abnormal, with a lower gas flow resistance (exhaust subpoint will fall).
In the electronic engine control systems, the resolution feed to the EGR valve diaphragm is performed through an electric valve. The electric valve can work on the principle open - closed or with a pulse modulation. In such systems, an electrical signal from the ECU to the solenoid solenoid should be checked, the solenoid itself, the integrity of the supply channel channels from the source to the EGR valve.
A set of controlled parameters of the EGR system, read by a car diagnostic scanner, depends on specific model The car usually these are the following parameters:
- The magnitude of the recycling flow in percent.
- The filling coefficient of the control signal during the operation of the electroclap on the principle of latitude-pulsed modulation.
- Switching status of the EGR valve (turned off).
Diagnostics of the EGR system.
To figure out whether the EGR valve should work in specific conditions, the technical documentation of the consumer car should be used.
Diagnosis of the main components of the EGR pneumomechanical system
Diagnostics require technical documentation from the manufacturer and measuring instruments: car multimeter, pressure gauge, manual vacuum pump, logical probe and oscilloscope. It is not superfluous to be a diagnostic device or scanner to output error information and the required current data.
Diagnosis of thermoclap, sensors and solenoids
1. The voltmeter controls the voltage on the contacts of solenoids in current and de-energized modes.
2. Ommeter is checked by the resistance of the windings of sensors and solenoids and the presence of a "mass" closure.
3. With the help of a vacuum pump and a pressure gauge, the correct operation of electric and thermoclap is checked.
4. With an oscilloscope or diagnostic scanner, you can check the output signals of all sensors used by the ECU when controlling EGR: positions throttle valve, revolutions crankshaft, pouring in the intake manifold, etc.
Diagnostics of the main valve system EGR
Typical malfunction The main valve is a leakage of the diaphragm in the vacuum chamber or a loose landing of the valve locking device due to contamination.
In EGR systems, without using exhaust compressions, the valve is removed from the engine, a manual vacuum pump is connected to its vacuum input, a vacuum is supplied with about 250 mm RT. Art. The valve stem must be drawn, and the locking device - to open, the applied vacuum will not be changed, and the stock change its position for no time. Otherwise, the diaphragm has a leakage and the valve should be replaced.
In EGR systems, using the backpressure of exhaust gases, the main valve of the EGR system is meaninglessly, since it will not work without supplying the pressure of the exhaust gases. In this case, it is necessary to follow the procedures for the verification recommended by the manufacturer, which usually provides for limiting the passage of exhaust gases through the exhaust pipe.
EGR diagnostics with electronic control systems
Electropneumatic Systems (EPS)
The vacuum is supplied to the EGR (EPS) system through a normally open electric valve, which is controlled from the ECU. When the fuel flow control system operates in open mode, the ECU closes the contact of the electric valve solenoid to the mass of the transistor key, blocking the supply of the vacuum on the EGR valve. If the EGR valve is open in the inappropriate engine operation mode, this indicates that there is no connection of the contact of the solenoid of the electroclap on the "mass" or no supply voltage on another contact of its winding. If the EGR valve does not open - the connection between the ECU and the solenoid contact is closed on the "mass" outside the ECU.
A latitude-pulse modulation can be used to control the recycling flow. The ECU periodically closes the contact of the solenoid of the electroclap on the "mass". The ratio of the duration of the included state of the solenoid to the period is called the filling coefficient, which is measured as a percentage. Typically, 0% corresponds to blocking the supply of the valve, and 100% corresponds to the fully open valve.
Using the multimeter connected to the shutters to the terminal in (Fig. Below) and "mass", you can check the solenoid switching frequency and the filling coefficient by the average voltage in the winding. Oscilloscope for such measurements gives a more visual picture than the multimeter.
With diagnostic purposes in the EGR valve, a vacuum key is embedded (Fig. Below). The ECU uses the key signal to test the resolution in the Vacuum line 1 of the EGR valve. The maintenance key works synchronously with the electroclap of its electrical signal can be monitored using a multimeter, an oscilloscope or a logical probe connected to contact with in the connector 6.
1 - Vacuum line to the EGR valve;
2 - line to the sprinkler source;
3 - diagnostic normally open vacuum key;
4 - shut-off spring;
5 - normally closed spring 4 and de-energized electric valve;
6 - connector;
7 - power bus;
8- ECU
EGR valve servo check
Ensure that the sound of the EGR valve operation is clearly heard ( stepping electric motor) When the ignition is turned on (without starting the engine). If the sound of the operating servo valve EGR is not heard, then check the servo power circuits. If the power supply is properly, then the servo drive itself or the electronic motor control unit is defective.
Checking the servo winding resistance 
Disconnect the EGR valve servo connector. Measure the resistance between the output "2" and the outputs of "1" or "3" servo connector. Nominal resistance: 20-24 ohms (at 20 ° C). Measure the resistance between the output "5" and the conclusions "4" or "6" of the servo connector. Nominal resistance: 20-24 ohms (at 20 ° C). Replace the gasket and tighten the valve fastening bolts with a nominal point.
Checking the work of servo
Connect the test wire harness to the EGR servo connector. Connect the wire from the positive output of the power source (voltage of about 12 V) to the "2" of the servo connector. Connect the wire from the negative output of the power supply of 12 B to the outputs "1" and "3" connector. At the same time check whether the easy vibration of the working step electric motor is felt.
The resource of various EGR systems ranges from 70 to 100 thousand kilometers (in domestic conditions about 50 thousand). After that, its components are subject to replacement. This is ideal. However, those who want to pay considerable money is a bit. Easy and timely service of the system will help extend her life. In the EGR pneumoclosphane, it is necessary to periodically clean the saddle and rod from the carbur with a liquid to clean the carburetor. It is necessary to make it carefully that the liquid, aggressive to rubber, when the valve does not damage it when it does not damage it. In systems with controlling electroclap in it, as a rule, there is a filter that protects the vacuum system from contamination. It must be cleaned.
When EGR begins to make failures, many car owners prefer to drown out. As a rule, this is done with the help of cut from a thin tin fastener installed under the valve. Among the experts on the silence of the system are diverged. Some consider it completely harmless, and some even useful. The second is believed that the temperature in the combustion chamber increases, and this increases the risk of cracks in the cylinder head.
Simple mechanical jamming of the valve and removing the vortex dampers (where there is) does not always lead to the desired results. Turbodiesels are possible problems with adjusting pressure and high wear of the turbine. On the modern engines EGR valve must "delete" and programmatically flashing the control unit. Otherwise, the controller will constantly issue an error or even translate the engine to alarm mode.
Developers modern cars The engines are constantly improving to improve the environmental component. The EGR system is one of the mechanisms that allow minimizing toxic emissions into the atmosphere by returning the part of the exhaust gases into the combustion chamber, while the operation of the diesel engine becomes more "soft." When operating power aggregate With EGR, many car owners face breakdowns or failures in the work of the recirculation system. The new item for replacement is quite expensive, but it is completely cleaned, repair or system is simply turned off.
How to work EGR in turbodiesel
The main function of the EGR system is a partial return of the spent gas in the intake manifold for the purpose of afterburning. On the diesel engine Such a solution allows you to achieve a softer and smooth engine operation, which improves its operational qualities and reduces fuel consumption, and exhaust reduces its toxicity. The appearance of exhaust gases in the inlet does not change the ratio of the main components of the combustible mixture, the power in different modes of operation is not lost, and the fuel is saved.
The principle of operation of the EGR valve on diesel engines is the compound of part of the exhaust gases with the air intake manifold. The engine exhaust contains nitrogen oxides due to increased heating of gases in the combustion chamber. When the EGR system is activated, the combustion occurs at a lower temperature, and the level of content harmful substances In the exhaust it becomes less. On diesel engines, the valve opens automatically at idle, and when loading and maximum power closes.
For what shuffle Valve Erp
For long operation Diesel equipped with EGR system, car owners often feel the reduction of power and the appearance of exhaust smoke. Motor tuning lovers argue that the recycling of gases "stifles" by the power unit, not allowing it to show the entire potential of power. Based on similar arguments, many drivers decide to drown out the system of EGR. Such a procedure is a disabling of the recirculation system, which theoretically must add power.
It is believed that the rapid formation of Nagara on the exhaust valve of the exhaust gases in the intake manifold provoke enhanced Nagar formation and the combustion of the combustion chamber. The malfunction of the EGR system associated with the failure of the valve leads to the overflow of fuel and the unstable operation of the engine. The combustion chamber includes resin and soot, because of which diesel oil Quickly oxidized, and the total power of the power unit is reduced.
The need to shut down the USR appears when running 80-120 thousand km, because the presence of such a run causes a certain wear wear. Exhaust gases, redirected inside, have a high degree of contamination. After their further mixing with crankcase gases, a thick layer of resinous sediments appears in the intake manifold, the valve of the USR and the engine head valves. The scored system causes errors and can provoke a sharp car transition to emergency mode.
Diesel malfunctions
The EGR valve is a part that performs a bypass function, which or passes part of the exhaust gases from the collector to the feeding line, where they are mixed with air (in case of service), or not. If the valve faults, the computer will display the corresponding error on the indicator dashboard. The malfunctions of the USR on the dieselle can be the following:
- Nagar in a system that affects the valve and the EGR plate. Excessive high formation occurs when the engine is operating on low-quality fuel, with incomplete combustion fuel mixes, violation of the outlet system carter gases.
- The clogging of the valve at which it occurs when opening or closing, or incorrect operation in the form of a late response, which is noticeable when the motor is at idle.
The malfunction of the USR is manifested in a frequent stop of the engine, floating circulation in idle mode, "Trojections", jerks while driving and drop in speed when accelerated.
Research the recirculation system is possible when visual inspection of the state of pipelines and sensor connectors. Accurate diagnosis includes electronic scans and other procedures in which the operation of the drives and the EGR valve is checked.
Repair of the USR on the diesel
The repair of the EGR system is its mechanical cleaning from nagar and sediments using a small metal brush and washing with a "WD" cleaner, which is designed to remove sediments and rust from metal. At the end of the procedure, the valve from the inside is wiped with a rag moistened in a solvent. The remote control of the solenoid (with any), which performs the function of the filtering element that protects against the garbage to the vacuum system.
Washing from Gary Valve EGR is carried out after its removal, processing through the holes with a special aerosol, used to clean carburetors, then the part is placed in a container filled with lighting kerosene. After disassembled, unscrewing 4 bolts, and cleaned from the inside. Such a service will eliminate the signs of the EGR valve fault, and will restore its proper operation. The procedure should be carried out regularly after 60-100 thousand kilometers.
How to drown out the valve EGR on the diesel
The correct disconnection of the EGR on the Diesel assumes:
- Mechanical method of stitching valve.
- Disconnection using the control unit.
At the first stage, the valve mechanical plug is installed, after which the system is turned off on electronic equipment. You should know that only physically drowning the valve is enough only on some cars. After making a mechanical locking of the valve requires its software shutdown to the computer, otherwise the "Check" lamp will burn on the instrument panel due to the recycling system errors, and the motor uses the emergency mode, which limits the distant power.
The easiest version of the valve plug is as follows:
- The valve, which is most often positioned near the intake manifold, remove, unscrewing several bolts.
- If necessary, dismantle the intake manifold and clean its channels from contaminants.
- Remove the gasket located on the place of the valve attachment.
- The setting is used as a template, which is cut out from the steel sheet, the plug, and the holes under the bolts are made in it. Often the plug under some models of cars can be found on sale.
- Reverse valve installation using gasket and plug. The tightening of the bolts is made with extreme caution due to their fragility.
- Turn off vacuum hoses, as they are no longer activated in the opening system.
- Making changes to the firmware of the ECU to get rid of EGR error.
The EGR - Exhaust Gas Recirculation car system, the thing is not very unambiguous and quite a capricious, especially with very low quality fuel, which is found in our parts, quite often. The ambiguity of this system is that its purpose is purely ecological. The reverse recycling system of exhaust gases or the USR is designed to reduce the number of nitrogen oxides in the automotive exhaust. What is EGR, why it is needed and how its faults are expressed, about all this, we will talk now.
It should be started with the fact that the USR system is installed on most diesel engines and gasoline, atmospheric units. The essence of this system is that at certain points, the EGR valve opens and a portion of spent gases is discovered in the engine intake manifold.
Sketchy image of the operation of the EGR system.
Thus, the amount of oxygen in the fuel mixture is reduced, which in turn reduces its combustion temperature. And with a lower combustion temperature, the number of nitrogen oxides in the automotive exhaust is reduced very significantly. If the engine is turbist, then the USR range is significantly narrowed, which makes it not rational. In such cases, other solutions apply that reduce the number of harmful components of the automotive exhaust.
Exhaust Gas Recirculation does not work at idle, it is not used when the engine is cold, as well as the EGR valve closes when the throttle is maximally open.
Management of the EGR system
The reverse recycling system of exhaust gases is controlled electronic block Engine control. A command to open or closing the EGR valve can be fed on the basis of:
- coolant temperature sensor;
- crankshaft sensor;
- throttle position sensor;
IN various models Car, in the management of the valve, the USR is used either all listed sensors, or some of them, and in some cases, only the cooling fluid temperature sensor.
What does the EGR valve look like on Chevrolet Lacetti
Anyway, the operation of the valve, the USR always controls the automotive electronics. And while this system operates regularly, the driver of her work, almost no way feels. The useful work of the EGR system outside the environmental theme is very small. This system saves about three percent of fuel on gasoline engines. Also in some cases, the EDR system prevents the detonation of fuel in the motor. But this phenomenon itself is rare and extraordinary. As for diesel units, if there is, a secondly functioning EGR system, they work more smoothly, gently, quiet. In addition, in motors on diesel fuel, the formation of soot is reduced. So all the bonuses that the owner provides the recycling system of exhaust gases.
Video about EGR
Why drowning egr
Often you can see the situation when the USER system is simply plugged. What is the matter, not really all motorists who do that do, care for harm from road exhausts?
In fact, the problem is as a fuel on which our cars drive. Low fuel quality, exhibits in addition to all other things, the formation of soot and sedimentation on the valve of the USR, as well as in her highway. This leads to the fact that the system either does not work at all, or it works incorrectly. In both cases, it is easier to drown it, for, replacement, even only an EGR valve, the pleasure is not cheap. So people decide the question, so to speak, radically. And since no special losses to disable the USR does not entail, then they are solved for this step, as a rule, without special oscillations.
Gasket for a plug of the USR (with one hole) and the regular (Chevrolet Lacetti).
The junction of the exhaust gas recycling system on gasoline engines can be done using the installation of a conventional washer in the lumen of the valve. If you use vortex dampers in the intake manifold to regulate the Vortex valve in the intake manifold, too. In diesel engines, in addition to the mechanical stitching of the EGR valve, it is necessary to disable it programmatically. Otherwise, the turbine wear increases and the stability of the power unit is disturbed.
Disputes about the silence of the USR, lasting until now. Some believe that this system can be swirling and necessary, others argue that after it is shutdown, the combustion temperature in the cylinders increases, which leads to a more rapidly generating the resource of the engine and its wear.
EGR system malfunctions
Diagnosis of problems with the described system, the task is not so simple as it may seem at first glance. The trouble is that there are no pronounced symptoms characteristic of EGR problems. The engine, it seems to be a troit, it seems to fail, and it seems not. And it is precisely a system for recycling exhaust gases, in such no stability of the motor, only a professional can. But before being checked various sensors, knots and car systems. Actually, what problems may arise:
- deposition on the details of the valve EGR, soot and other elements leading to the encoding of it in any position;
- exercise valve exercise;
- clogging of the highway EGR;
- violation of electronic valve control systems EGR;
If the valve or highway is tritely clogged, clean them, in general, it is not difficult, although in some cases such cleaning is simply impossible. Well, if the valve burned, you will have to change it, and this, as already mentioned, is not cheap.
Symptoms that are characteristic of problems with the valve of the USR is actually absent. This is for example, the unstable operation of the engine, in idle speed, unmotivated failures in power, the absence of a pronounced acceleration with the full opening of the throttle, and other signs of violations in the operation of the motor.
One way or another, do not rush to change the EGR valve or shrink it if there are no obvious damage to the valve and its parts. Perhaps the problem here is not entirely in the USR, for this system is closely interconnected with other nodes and air regulation systems and the removal of spent gases.
One of the characteristic phenomena of the automotive case is that even if the driver has a great experience of daily working with a car, some of his "highlights" he can simply not know or know very superficially. This paradox directly concerns such an unexplored by many to the end of the valve as EGR, which is installed on most modern machines. Interestingly, there are also such drivers who did not hear about such a valve at all.
What do I need an EGR system
First of all, it is necessary to deal with EGR - what is in the car and for which it is intended. The term itself occurred from the English "Exhaust Gas Recirculation", which is translated as "valve recycling of exhaust gases", denoting the EGR abbreviation. Among his drivers for brevity is just the "Valve EGR". It belongs to the number of those devices, at the expense of which car manufacturers are trying to effectively solve large-scale and increasing, in this case - to reduce the level of environmental pollution. Such an original sensor must, according to the design of the designers, raise the efficiency of the engine functioning.
He has a different key task, closely conjugate with the first, is to achieve. This is done at the expense of exhaust gases, speaking more precisely - with the help of reuse. Is it necessary to talk how important it is in our time with a lot of energy problems! In the West, such a technique has been used for a long time, it becomes more and more common with us.
Types of exhaust gas recycling systems
Modern valve recycling of exhaust gases EGR can have three different formatswhich differ from themselves not only externally, but also by the principle of action, the drive method. In particular, the pneumomechanical system is hardly the most simple, and therefore, in essentially, outdated technically and morally model. In it, the valve is controlled by creating a vacuum in the intake manifold. The electropneumatic system is upgraded in such a way that the EGR valve is controlled due to the electroclap, which manages the motor ECU based on sensor information. And finally electronic system Designed so that the EGR valve is, figuratively speaking, in direct submission of the ECU. He, in contrast to the previous version, not two positions, and three, which allows you to more smoothly adjust the flow of exhaust gases.
Design and principle of operation of the EGR valve
Redesigned over the years, the exhaust gas recycling system is quite witty. It works effectively on the principle of returning a certain in advance of spent its gases back to the "initial positions" - into the space of the intake manifold. And this is done in a strictly intended time. There is a process of mixing such gases with flammable and air. The formed "old" mixture comes back to the motor cylinders together with a new, fresh mixture of fuel and air. The desired number determines the ECU control unit using the program laid into it at the factory, given the data of a series of sensors and a place where the recycling valve of EGR exhaust gases is located.
EGR faults and their diagnostics
Based on the practice, the characteristic signs of the malfunction of the EPR valve, not allowing it to fulfill its direct appointment to fully:
- frequent motor stops;
- motor power drop is recorded when the car is accelerated;
- detonation or t. n. "Trojection", unnatural car jerks, when it moves.
All this leads to a weak, insufficient recycling of crankcase gases, significantly reducing the efficiency of the engine. Special attention requires a valve EDR in diesel engine. So, experts recommend regularly cleaning it from deposits and nagar every 50 - 100 thousand. This is one of the basic ways to prevent valve. Given its importance for the economical functioning of the car, the periodic diagnosis of the valve should become for the driver of the norm and is carried out systemically to avoid its unexpected failure.
It should be remembered that for full-fledged diagnostics, special equipment is needed, so without a target trip to the service station, so as not to conduct a study in handicraft conditions, it is not necessary to do.
Why drowning egr
Problems in the work of Valveov EGR prompted drivers to seek an effective antidote. The fact is that it is necessary to change not only the valve itself - a thorough cleaning of other parts is required, and this is a very expensive process. Therefore, there are quite a few drivers without special pondays resort to the valve plug. If this is technically competent, the engine will be delivered from an unforeseen and unwanted problem moment. Moreover, sometimes such a plug will even increase the efficiency, the efficiency of the power unit. In a word, of two angry will have to choose the smaller - precisely in the interests of the engine.
However, there is a reasonable question in terms of drowning the system, especially own forcesnot to aggravate the situation. Experts recommend to take advantage of careful consultation with car service professionals on wise principle "One mind is good, and two are better!". Let you all luck!
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