The valve of the USR is set. EGR in diesel engine: what it is. Where is the EGR valve

Modern cars Equipped with electronics to the maximum, and with the release of each new model, this number is only grows. Let's first deal with one of the most popular questions that the EGR sensor is for which it is needed and other adjacent moments. Let's start with the decryption - Exhaust Gas Recirculation. This is a recycling system exhaust gasesTo comply with the parameters with European, to reduce emissions at all non-beneficial substances into the environment.

What is an EGR sensor and for which it is actually needed, we will consider in detail below, so take patience. It is installed on all engines (except for turbocharged options). Thanks to this sensor, the risk of engine detonation is reduced and fuel consumption drops slightly. However, despite such substantial advantages, this system is very capricious Madame. Thanks to not quite high quality fuel, it is quickly covered by Nagar, which directly affects the unstable engine operation.

Clean and repair - the lesson is long, tedious and not a noble, so the owners of the machines with EGR, about 70-80% of cases, simply devils completely. It is faster and cheaper, ask any car mechanic - he will confirm it.

Principle of operation

The essence of this system itself is to mix parts of exhaust gases to oxygen in the intake manifold. Due to temperature and combustion fuel mixes, exhaust toxicity decreases

Device. The main part of the system is the EGR valve. It regulates the spent gases sent back to the intake manifold. The principle of operation on all brands of machines is the same, which you can not say from the design options. There are several system options:

• The opening of the valve is regulated by the electrical method, based on the position sensor data from which the signal is already on the engine controller;
• The electropneumatic system sends a signal based on the data, the temperature sensor on the inlet and pressure in the intake manifold.

There are engines where additional gas cooling is installed. There EGR valve is built directly into the cooling system. It is more difficult to constructively (especially in repair or maintenance), but the Europeans suspended on ecology, even more like this version of execution.

In diesel engines, the EGR valve opens at idle, taking about half the air at the inlet. With increasing engine speed, it begins to close when maximum load. An interesting point is that when driving a motor, the valve is completely closed.

IN gasoline engines, on the contrary, at idle, it is not active, as at the peak. With an average load, it provides no more than 5-10% inlet air.

Immediately need to say that this sensor works in a bundle with others, and their number is constantly changing depending on the brands and machines.

Fault

As I wrote above, all malfunctions are in nagar on the valve (or its nest, do not essence). It is taken from bad fuel, other sensors. In fact, the causes of the malfunction can be more than more, and most often need to be corrected a whole group, and not something specific.

The deployed Nagar in the literal sense leads to sticking, or slows down the trigger (opening \\ closure, valve). On gasoline engines, this will manifest itself in reducing power, increasing fuel consumption, unstable work at idle.

On the diesel enginesThe problems will not be so pronounced, basically you will notice the changes not for the better only at idle. For example, the engine starts and at first works normally, but after about 10-15 minutes (in certain cases it may be 1 and 2 hours ), Begin interruptions, similar to the trottery. Determine the rumor that the trouble is in the EGR sensor - insanely difficult, there is an experience.

The engine is the heart of the car, it is his technologies that are trying to improve engineers. Modernization affects the design, methods that promote the efficiency of the unit, reduce the toxicity of emissions generated during the combustion process of the fuel and air mixture. Exist various methods Achievements of the goal, for example, using the Exhaust Gas Recirculation Gas Recycling System (EGR). The need for the installation of the USR, the design and principle of operation of the system, possible problems And their elimination paths are interested in many car owners.

What is EGR?

EGR - contour recycling of waste gases. The main component of the system is the valve connecting in the programmed modes of the exhaust manifold with the binding space of the intake manifold. The result is to reduce harmful emissions with exhaust gases to the environment.

Where is the device (examples).

Find valve EGR is easy - it is installed on the engine of the car in the immediate vicinity of the intake manifold location and appearance Products depend on the brand and model of the car:

• Opel Astra G The device should be signed under the upper right corner of the protective cover;

• Ford transit VI (diesel) - in front of the motor, to the right of oil probe;

• Volkswagen technical - on the flange of the intake manifold;

• Opel Omega - to the right of the ignition distributor;

• Ford Focus - in the area air filter under nozzles;

• Peugeot 406 (2.1 TDI) - directly above the engine, next to the intake manifold;

• Chevrolet Lacetti - next to the ignition module (check and maintenance will not require, even dismantling protection).

Purpose.

The main purpose of the USR is to reduce the amount of nitrogen oxides generated during the operation of the engine. Under the action of high temperature and pressure characteristic of the combustion process of the fuel and air mixture, excess oxygen react with air nitrogen.

Main principle of Err. - reduction of oxygen content. Opening at a certain point, EGR adds a portion of spent gases to the airborne air. Accordingly, the concentration of oxygen in the mixture is declining, with a constant ratio of air / fuel remains unchanged. The oxygen-depleted mixture is combined under reduced temperature, the intensity of the formation of nitrogen oxides is reduced.

Specialists argue that deterioration performance characteristics power aggregate When using the mixing technology into the absorbed air of exhaust gases does not occur. On the contrary, improving certain characteristics is achieved. For example, an EGR installation on a diesel engine significantly reduces the rigidity of the unit. In gasoline engines, fuel consumption and pumping losses are reduced, detonation is prevented, the possibilities of adjusting the ignition advance angle are expanding, the growth of torque is observed.

Principle of operation.

Depending on the manufacturer, the model and year of production of the auto, three options for implementing the exhaust gas recirculation devices are used:

• Pneumomechanical

Characterized for the first USR. The system uses a vacuum valve control.

• Electropneumatic.

It is found on the machines corresponding to the EURO 2 and 3. Algorithms of the EGR functioning of this type is simple, but quite reliable. 2 valves correspond to recirculation. Pneumatic directly performs opening / locking channel used to supply exhaust gases to the intake manifold. Electromagnetic - creates the vacuum required for the pneumatic damper.

The control team that admits in the combustion chamber of the mixture depleted oxygen is formed electronic block Controls based on temperature measurements in exhaust gas removal systems and cooling, pressure in the inlet path, the current valve. The corresponding signal is fed to the electric valve, the latter opens, creating a vacuum for a spring-loaded pneumatic damper diaphragm. affecting a valve device. The pneumatic valve opens (only 2 positions are possible in the system).

• Electronic (digital).

The device is installed on modern cars that match EURO 4 and higher environmental classes. It is controlled directly by the ECU signal, in addition to the positions openly / closed may be in the intermediate, providing a partial throughput of the recycling path.

Regardless of the design used, a properly functioning EGR does not allow the recycling of exhaust gases at:

• engine warming vehicle (until a temperature is 60 ° C), since in this mode, a high combustion temperature of the fuel-air mixture is necessary;

increased loads and at idle petrol aggregatesTo avoid reducing the peak motor power when mixing exhaust gases.

Video on the work of the part.

Major faults.

Most problems in the gas recycling system are associated with the main element - the valve of the USR. The causes of malfunctions are the effects of hot gases and contained particles of unburned fuel contained in them. The result of such an impact is a clogging of EGR by Nagar, leading to a subfluous (untimely triggering) or a complete shiny of the flap in an open / closed position.

The characteristic symptoms will help to identify the encoding in extreme positions. With a constantly open damper, there are:

• reduction of motor power;
• unstable work in idle mode;
• rods during acceleration.

With closed - increased gasoline consumption and tighter diesel operation.

Sweeping and untimely triggering EGR is more complicated. The main manifestation of malfunction is idling.

The cause of EGR failures becomes not only the valve, in order can be released:

• vacuum amplifiers;
• thermocladas, damage control;
• solenoids;
• channel of exhaust gases;
• exhaust gas pressure transducers;
• drinking tubes.

Specific cases of malfunctions Egr require careful diagnosis using appropriate instruments: a diagnostic scanner, an oscilloscope, an ohmmeter, voltmeter, etc., the availability of detailed technical documentation for the car.

How to check?

The optimal option for diagnosing EGR faults is the use of electronic equipment. Testing techniques allow you to spend a minimum of time and get specific error codes. The decoding will help accurately establish the failed nodes.

Error codes that may meet:

• Р0400 - error of the EGR system;
• Р0401 - insufficient consumption in the system of re-burning exhaust;
• Р0403 - failure of the exhaust gas recycling system;
• P1403 - the error of the main valve of the system;
• P0404 - Width of the EGR control valve system.

Such an inspection is not always available to the motorist. It requires the availability of appropriate equipment and comprehensive information on technical characteristics Systems. The presence of data allows you to compare the current indicators with the declared manufacturer of the characteristics of the EGR as a whole and each element, which will ensure an accurate understanding of the causes of the fault.

In the absence of computer stands (devices, terminals), the test is carried out in a traditional way:

1. Disconnect vacuum hoses and blow the valve. The air should not pass through it.
2. Disconnect control conductors electromagnetic valve.
3. Calculate, connecting the device with wires from the battery, try to blow EGR again. A channel of free passage of gas (air) should be provided.

Faulty EGR replaces new, in most cases a banal cleaning helps.

If the problems are overtaking on the road, the solution method will turn off the gas recycling system. Some motorists prefer to perform a similar operation on the working system, since it is believed that EGR leads to loss of power (it becomes particularly noticeable when there are more than 100 thousand km run.). The simplest answer to the question: how to drown out the USR - install a metal (steel) plate instead of gasket. You should know that the method requires both a software shutdown device to eliminate errors in the ECU function algorithm.

Video with verification example.

How to clean?

First go back necessary tool: screwdriver, precipitated and horn keys, trimmed paste, rag and carburetor cleaners - foam and in the form of spray.

Find out the device type installed in the machine. Pneumatic needs to clean the saddle and rod, the electric - filter protecting the vacuum system from the cloth.

Repair are carried out in the following order:

1. Disconnect power out on-board networkAfter removing the battery terminal.
2. Provide access to K. valve Erg. (for specific model Auto required different actions),
3. Split and remove the clamps, fastening nozzles, disconnect them from the device.
4. Twisted (better, ratchet) fixing bolts. It is required to show caution with the bottom pair of nuts - fasteners are easily lost.
5. Remove the USR, remove from open spaceMachine in flushing for carburetors for 5-10 minutes.
6. Clean the details of the rag with the cleaner.
7. The assembly and installation of the EGR valve is produced in reverse order.

If you need to follow the following conditions:

• after dismantling, the ruble gasket always changes to a new one;
• the correctness of the connection of vacuum tubes and their integrity is subject to mandatory verification;

a high-temperature sealant is applied to the threaded joints of the thermoclap, in addition, the protracted efforts should be controlled, otherwise not to avoid leaks.

Video instructions for cleaning the device.

Removing the valve of the USR and its plug.

Low fuel quality and, as a result, frequent breakdowns Recycling of exhaust gases, as well as the high cost of its repair / replacement leads to the fact that many car owners are simply disconnected / muffled this system.

This is done with the help of the engine tuning chip, which disables gases recycling through the ECU. As a result, the computer does not see the valve operation and does not give an error. However, the valve itself does not cease to function from this, so it is necessary to exclude from the system to a complete solution to the problem, it is also mechanically to do it. simple removal Details or installation in it plugs. These plugs are many automakers if your such original spare parts No, it can be made independently, just cutting it out of thick (up to 3 mm) of the steel plate on the shape of the valve opening.

But remember: the installation of the plug leads to an increase in the temperature in the cylinders, which increases the risk of appearance cracked GBC., Therefore, we have all segregate several times before proceeding to action.

• Remove the EGR valve - how to do it, described above.
• Clean its channels from pollution.
• In place of the gasket installed in the valve mounting place, put the plug.
• Return the EGR to the place.
• Perform the engine chip tuning so that the computer does not give out an error.

Perhaps someone this procedure seemed simple, but believe me, it is only at first glance, so it is better to exercise it in specialized centers. Only so you can be sure that the procedure has done will bring you and your car more benefits than harm.

Video instructions.

Pros plubs:

• increased motorcycle oil life;
• improved dynamic characteristics of the car;
• lack of the need to repair / replace failed EGR;
• soot and other combustion products do not fall into the intake manifold and do not pollute it.

• increased nitrogen oxide emissions;
• reduced catalyst life;
• increased fuel consumption;
• risk of detonation in a gasoline motor.

Please note that the title and negative points of the plug installation are sufficiently conditional, because in different cars Recycling of exhaust gases interacts with other systems in different ways, so in each particular case, the lists may be supplemented or cut into one or more points.

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Today, all manufacturers are trying to make their cars as much as possible. Therefore, the EGR system was developed. There are many disputes about which engine is ecological. In fact, how many people have so many opinions. Someone considers it cleaner than diesel, but someone vice versa. In order to clean the exhausts into the atmosphere, the EGR system was created.

Device

The EGR system is designed so that the cleaning of exhaust gases occurs by returning the part of the gases back to the intake manifold. Return of spent gases provides an EGR valve. Since the engine principle engines are not different, it differs only the EGR valve drive.

There are two ways to adjust the EGR valve.

• In the first case, the adjustment occurs with the help of the engine controller internal combustionthat sends all the instructions. In this case, the controller takes this data from the position sensor. This method is called electric.
• There is also a second way, it is called electropneumatic. In this method, the EGR system is based on the testimony of pressure sensors and temperature on the intake manifold, as well as on the sensor readings mass flow air.

Advantages and disadvantages

The main disadvantage of the system is the rapid pollution of the intake manifold. This process is inevitable, so who has an EPR, still in the end receive a contaminated intake manifold. There are several more minuses, the main of which is rapid wear of sensors and valve EGR. There is another minus, which may not be, if you properly exploit the car. This minus is considered to be Nagar, which is postponed on the valve of the USR and nest. So, this deficiency can be circumvented.

In order for the NAAR not postponed, it is required to fill the car with high-quality fuel.

Nagar remains due to the fact that the cylindropional system is wearing. The malfunction of the sensors that regulate the operation of the USR valve, the malfunction of the power system, the turbocharger, the ventilation of the crankcase - all this also leaves the nagar on the ruble valve. If you keep track of and on time to care for the engine, then this lack may not be.

In addition to the disadvantages of the EGR system, there are a number of advantages. On the gasoline engine Internal combustion during the operation of the USR system, decrease pressure jumps in the mixed chamber during opening and closing throttle valve. In the gasoline engine, the temperature of the combustion of fuel is reduced, which reduces detonation. Reduced detonation allows you to install earlier ignition, this in turn increases the instantage characteristics of the engine. EGR on diesel engine Allows it to work quieter and even more at idle. It happens because during the combustion of fuel in the system, the pressure drops due to the fact that there is less oxygen.

Breakdown

Often, breakdowns occur, as in other car systems, is inevitable. Most often, breakdowns occur exactly due to the fact that the nagar on the EGR valve or the nest appeared. It happens because the engine works on low-quality fuel. The EGR valve can be sealed due to improper operation of the turbocharger, pistons or cylinders, and even with incomplete combustion of fuel in the combustion chamber. If the sensors that contribute to the operation of EGR work incorrectly or do not work at all, this will also lead to deposits.

When the EGR valve is covered by Nagar, it stops working in the mode in which it worked before. There are situations where the valve encourages. In any case, it is impossible to allow. The fact that the valve does not work on time can be seen during idling. This will not lead to the deposits for the internal combustion engine.

In the second case, when the valve is jammed, the gasoline engines at idle will work unstable. In such a gasoline engine, fuel consumption may increase in such a situation. Diesel engines in turn will work tougher and louder, and the engine will significantly reduce the power.

In order to correctly determine the EGR breakdown, it will be necessary to visually inspect all pipelines, as well as sensor connectors for mud. In order to confirm guesses, it will be necessary to diagnose, which will show the valve status for the presence of a car, and will also show the collector's clogging.

If it was determined that the valve was covered with Nagar, then it should be changed. During the replacement of the EGR valve, it will be necessary to clean all the systems that work together. It is necessary to do this because of the fact that the remnants of the Nagar can lead to a re-same breakage.

Jumping

Many owners of cars with EGR believe that she "shakes" the engine and does not give it to work on full power, Therefore, come to such a solution how to drown it. It should be noted that all the engines are different, and the system is installed in different ways. You can drown in two ways to drown.

1. The first method is joining the programmate. This procedure is not cheap. The cost of stitching EGR is approached by 9,000, and for some engines at all in 14,000 rubles.

But you should not despair, there is a second way to join the system.

1. Mechanical way to stop the system operation, you just need to remove it. To stroke the second way, you will not need a lot of time and effort, only a new gasket will be required. The new gasket does not have a second hole. Such a gasket can be purchased on the pages of online stores or make yourself.

This fact is important that you should not make such a laying of aluminum cans, because they will not stand the temperature and will turn into the system that will not lead to good consequences.

The new gasket, unlike the factory laying, does not have one hole. After the factory gasket was removed, you need to put a new and assemble the system back. You do not need to turn off the sensor, which is installed on the valve in order to do not burn Check Engine.

Summary

After reading the article, you can learn a lot about EGR, how to drown it. All the advantages and disadvantages of this system, as well as methods for its disconnection and breakdowns are described in detail. Each driver at the expense of EDR develops his opinion, and only to make a decision to join or leave this system.

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 the power unit with EGR, many car owners face breakdowns or failures in the operation 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 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 combustible mixtureThe 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:

1. Nagar in a system that affects the valve and the EGR plate. Excessive formation of Nagar occurs when the engine is operating on low-quality fuel, with incomplete combustion of the fuel mixture, violation of the cutter gases.
2. 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:

1. Mechanical method of stitching valve.
2. 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:

1. The valve, which is most often positioned near the intake manifold, remove, unscrewing several bolts.
2. If necessary, dismantle the intake manifold and clean its channels from contaminants.
3. Remove the gasket located on the place of the valve attachment.
4. 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.
5. Reverse valve installation using gasket and plug. The tightening of the bolts is made with extreme caution due to their fragility.
6. Turn off vacuum hoses, as they are no longer activated in the opening system.
7. Making changes to the firmware of the ECU to get rid of EGR error.

on the single engine Troit if you can say about V6 !!!)
It can even be stuck further look at the candles to gear the upper air is not difficult, but there is a hemorrhea. Next, you can drove the USR between the tube and the sensor to put 1 rub. (The coin is so in our way!) Save answer if anything, and forgot another 1 sensor on 2 tubes and it can also be checked for a "differential pressure sensor in the recycling system of exhaust gases"

Exhaust Gas Recycling System
(EGR SYSTEM) So, a few words about the EGR system (exhaust gas recirculation), which means "recycling of exhaust gases." From the very name it becomes already clear that the principle of operation of this system is based on the return of a certain amount of exhaust gases back to the engine cylinders for final burning.

Deal with a malfunction that occurs due to the wrong or unstable work Systems "EGR" - the case is quite difficult, especially for a novice auto repair mastery. It is probably due to the fact that everyone is accustomed, mainly to the so-called "ordinary" faults: "Troit engine", "the engine does not start", "the" engine "shakes" "and so on. The malfunction of the EGR system does not relate to the "ordinary" faults (if they can be called it), because it is masked or under the same "missing", or "unscrewing air", or something incomprehensible at all.

For example, the engine starts and first works absolutely normal, but passes 10-15 minutes (and in some case - an hour or two hours of operation) and some strange, not quite explained interruptions - the engine "Troit" , then -l "turns", something else. "For rumor", it is quite difficult to determine such a malfunction. In addition, not every wizard and not in each workshop there are special devices recommended by the manufacturer to check this system.

So the EGR system is not the "most recent link", which should be paid attention to.

The principle of operation of the system is based on the return of a strictly defined amount of exhaust gases back to the intake manifold in a strictly defined time. Next, mixing with air and fuel, the exhaust gases arrive back into the engine cylinders together with the fresh fuel mixture. This amount is determined by the control unit (ECU) on the program, on the manufacturer of the program based on sensor readings: Cooling fluid temperature sensor (THW); Sensor absolute pressure (Map-Sensor) or Sensor Air Flowmeter (MAF-SENSOR); Throttle position sensor (TPS); Air temperature sensor in the intake manifold (THA - not on all models). EGR's own sensors.

The amount and purpose of the sensors may be different depending on the car model, the year of release and the country of destination, that is, for which country this car is released.

The above is not a dogma, because various versions of the EGR system are possible. If the "Egr" system controls, for example, a computer based on the readings of the coolant temperature sensor, some other sensors or sensors, then on the other, the entire system is controlled by one electromagnetic valve and vacuum of the intake manifold (this is the so-called classic system).

It should be noted that the "EGR" system does not work constantly, and according to a special program (if the crossing was carried out constantly, you can imagine - what the ratio of air and gasoline would have come to cylinders, not 14.7: 1, but it is not clear what).

What is EGR and how to treat him?
EGR - EXHAUST GAS RECIRCULATION (exhaust recycling system)
This system is designed to reduce the formation of nitrogen oxides formed during engine operation. The formation of these substances takes place at very high temperatures. To reduce the temperature and, consequently, the formation of nitrogen oxides, a small amount of exhaust gases returns back to the engine.

EGR system is not used at idle. (Heated engine)
EGR system is not used on a cold engine.
The EGR system is not used with a fully open valve.

The EGR system is managed by Electronic Concentrated Control System (ECCS) and uses the crankshaft position sensor data (Hall sensor), engine temperature sensor and throttle position sensor. ECU translates these data into control signals to EGR electric valve, which directly controls the opening of the EGR valve. During the start of the cold engine, at idle when the turns are less than 900 rpm and increased turns Over 3200 rpm, EGR electric valve is turned on and the system does not work. In other cases, the electric valve is turned off and EGR works.

Circumstances in which the EGR valve is open:
The temperature of the coolant 50 Celsius and above.
-Adal gas is half pressed.
- Exhaust gases are enough to close the EGR valve.
All engine parameters (ignition, injectors) are normal
1. Dips in acceleration with a smooth speed set, or a small failure during the transition from the first to the second transmission. Too big stream through the EGR system
2. If there is a jerk with a smooth press of the accelerator pedal and there is no sharp acceleration with a "sneaker to the floor", then most likely too small flow in the EGR system

Possible causes of heavy streams through the EGR system
1. Weakened the calibration spring of the EGR valve. Valve replacement.
2. A damaged catalytic converter (clogged with combustion products) or exhaust system. (Check the exhaust system)
3. The idle turns are too high. Setting idling.
4. EGR valve inappropriate type. Put the recommended type valve

Possible causes of too small stream in the EGR system
1. Faulty valve EGR.
2. The opposite pressure is too high. Breakdown exhaust system, improper liquidation of the catalyst.
3. The control tube of the EGR valve is clogged. Throw the tube.
4. The idle speed is too low. (Configure turns according to the specification).

Checking the health on Nissan - I do not think that it is very different from ISU.

EGR valve. Location of the valve - behind the injector, over the back of the intake path.
1. Place the finger under the EGR valve and press the diaphragm below. It should be moved from the open state into a closed easily and without jamming. Otherwise, the valve needs to be replaced.

2. Run the engine and let it warm it. Press the EGR valve diaphragm again. During the opening of the valve, the engine must reduce the revolutions, should appear failure or the engine will stall due to the depletion of the mixture. If this did not happen, the tube of combustion products is clogged.

3. If a BPT valve and TVV valve are installed, disconnect the vacuum line from them and connect the EGR valve directly. Give the engine to warm up to operating temperature And ask the assistant to slightly press the gas pedal and hold the engine turnover within 2000-2500 rpm. Remove the tube with a vacuum control signal from the EGR valve and check as the valve diaphragm smoothly closes in accordance with the increase in engine speed. Install the tube with a vacuum signal back to the valve. Make sure that the diaphragm smoothly rose in accordance with the reduction of engine speed.

4. If the diaphragm does not move, make sure that the vacuum reaches the EGR valve: on the engine running at 2000 - 2500 rpm. Remove the tube with a vacuum control signal from the EGR valve and plug it with a finger. If you feel the airproof, replace the EGR valve. If there is no vacuum on the tube, carefully inspect the entire vacuum line for cracks, breaks and blockages. Also, if there is a TVV valve and delay valve, check their performance.