Material from the encyclopedia of the journal "driving"
Volkswagen FSI engine circuit with direct gasoline injection
The first gasoline injection systems directly to the engine cylinders appeared in the first half of the twentieth century. and used on aircraft engines. Attempts to apply direct injection in gasoline engines of cars were discontinued in the 40s of the twentieth century, because such engines were treated expensive, uneconomical and highly smoked at high power modes. Injecting gasoline directly into cylinders is associated with certain difficulties. Nozzles for direct gasoline injection work in more complex conditions than those installed in the inlet pipeline. The head of the block into which such nozzles should be installed, it turns out more complex and expensive. The time allocated to the mixing process during direct injection is significantly reduced, and therefore, for good mixtures, gasoline must be supplied under greater pressure.
With all these difficulties managed to cope with Mitsubishi specialists, which for the first time applied the system of direct gasoline injection on automotive engines. The first serial car Mitsubishi Galant with an engine 1.8 GDI (Gasoline Direct Injection - the direct gasoline injection) appeared in 1996.
The advantages of the direct injection system are mainly in the improvement of fuel efficiency, as well as a certain increase in capacity. The first is explained by the engine capacity with a direct injection system to work on very poor mixtures. Increased power due to the fact that the organization of the fuel supply process into the engine cylinders makes it possible to increase the degree of compression to 12.5 (in conventional gasoline engines, it is rarely possible to establish a compression ratio over 10 due to the onset of detonation).
GDI engine nozzle can operate in two modes, providing a powerful (A) or compact (b) torch of sprayed gasoline
In the engine GDI, the fuel pump provides a pressure of 5 MPa. The electromagnetic nozzle installed in the cylinder head is injected by gasoline directly into the engine cylinder and can operate in two modes. Depending on the supplied electrical signal, it can inject the fuel or a powerful conical torch, or a compact jet.
The engine piston with direct gasoline injection has a special form (process of combustion over the piston)
The bottom of the piston has a special form in the form of a spherical excavation. This form allows you to spin the incoming air, to send the injected fuel to the ignition candle installed in the center of the combustion chamber. The inlet pipe is not located on the side, but vertically from above. It does not have sharp bends, and therefore air comes with high speed.
In the engine work with a direct injection system, three different modes can be distinguished:
1) mode of operation on ultra-walled mixtures;
2) mode of operation on the stoichiometric mixture;
3) the mode of sharp accelerations from small revolutions;
The first mode is used in the case when the car moves without sharp accelerations at a speed of about 100-120 km / h. In this mode, a very poor combustible mixture is used with an excess air coefficient of more than 2.7. Under normal conditions, such a mixture cannot ignite from the spark, so the nozzle injected the fuel to the compact torch at the end of the compression tact (as in the diesel). The spherical recess in the piston guides the fuel stream to the spark plug electrodes, where the high concentration of gasoline vapor ensures the possibility of mixing the mixture.
The second mode is used when driving a car with high speed and with sharp accelerations when it is necessary to get high power. This movement mode requires the stoichiometric composition of the mixture. The mixture of such a composition is easily flammorated, but the GDI engine has improved the compression ratio, and in order not to adopt the detonation, the nozzle is injecting the fuel with a powerful torch. The finely sprayed fuel fills the cylinder and, evaporating, cools the surface of the cylinder, reducing the likelihood of detonation.
The third mode is necessary to obtain a large torque with a sharp press of the "gas" pedal when the engine operates on small turns. This engine mode is characterized by the fact that during one cycle, the nozzle is triggered twice. During the intake tact in the cylinder for its cooling, an ultra-walled mixture is injected with a powerful torch (α \u003d 4.1). At the end of the tact of compression nozzle once again injects fuel, but compact torch. At the same time, the mixture in the cylinder is enriched and detonation does not occur.
Compared to a conventional power engine with a gasoline distributed injection, the engine with the GDI system is about 10% more economical and ejects 20% less carbon dioxide into the atmosphere. Increased engine power reaches 10%. However, as shown by the operation of cars with engines of this type, they are very sensitive to the content of sulfur in gasoline. The original gasoline injection process was developed by ORBITAL. In this process, gasoline is injected into the engine cylinders, in advance mixed with air with a special nozzle. Orbital nozzle consists of two jaws, fuel and air.
Orbital nozzle work
Air to air jackets comes in a compressed form from a special compressor at a pressure of 0.65 MPa. The fuel pressure is 0.8 MPa. First, the fuel jacker is triggered, and then at the right moment and air, therefore the fuel-air mixture in the form of an aerosol is injected into the cylinder, a powerful torch.
The nozzle installed in the cylinder head next to the spark plug is injected into the fuel and air jet directly to the spark plug electrodes, which ensures good ignition.
Constructive engine features with direct injection of gasoline Audi 2.0 FSI
The performance of any vehicle, first of all, is provided by the serviceable work of its "heart" - the engine. In turn, the component of the stable activity of this "body" is the coordinated operation of the injection system, with the help of which the fuel needed is supplied. To date, thanks to a lot of advantages, it completely displaced the carburetor system. The main positive point of its use is the presence of "smart electronics", which ensures accurate dosage of the fuel and air mixture, which increases the power of the vehicle and significantly increases fuel efficiency. In addition, the electronic injection system in a much greater extent helps to adhere to strict environmental norms, the question of which recently becomes increasingly relevant. Considering the foregoing, the choice of the topic of this article is more than appropriate, so that let's consider the principle of operation of this system in more detail.
1. The principle of operation of electronic fuel injection
Electronic (or a more well-known version of the "Injector" name) The fuel supply system can be installed on cars both with gasoline and C However, the design of the mechanism in each of these cases will have significant differences. All fuel systems can be divided into such classification features:
- in the method of supplying fuel is distinguished by intermittent and continuous feed;
The type of dosing systems differ distributors, nozzles, pressure regulators, plunger pumps;
Behind the method of controlling the amount of fastened combustible mixture - mechanical, pneumatic and electronic;
The main parameters for adjusting the composition of the mixture - the discharge in the inlet system, at the angle of rotation of the throttle and air flow.
The fuel injection system of modern gasoline engines has either electronic or mechanical control. Naturally, a more advanced option is an electronic system, as it can significantly better provide fuel economy, reducing the level of emission of harmful toxic substances, increasing the power of the motor, improve the overall dynamics of the machine and relief of the cold start.
The first, completely electronic system, became a product released by the American company Bendix. In 1950. 17 years later, a similar device has created Bosch, after which it was installed on one of the models Volkswagen. This event marked the beginning of the mass distribution of the electronic fuel injection control system (EFI - Electronic Fuel Injection), and not only on sports cars, but also on vehicle vehicles.
Fully electronic system uses for its work (fuel nozzles), all activity is based on electromagnetic action. At certain moments of the engine's working cycle, they open and remain in this position throughout the entire time required to submit one or another fuel. Ie, the opening time is directly proportional to the required number of gasoline.
Among the fully electronic fuel injection systems, the following two types are distinguished, differing mainly only by the method of measuring the air flow: The system with indirect measurement of air pressure and S. direct measurement of air flow. Such systems, to determine the level of the recruitment in the collector, use the corresponding sensor (MAP - Manifold Absolute Pressure). Its signals are sent to the control electronic module (block), where given the similar signals coming from other sensors are processed and redirected to an electromagnetic nozzle (injector), which causes its opening to the necessary air.
A good representative of the system with a pressure sensor is the system Bosch D-Jetronic (Little "D" - pressure). The operation of the electronically control injection system is based on some features. Now we describe individuals characteristic of a standard type of such system (EFI). Let's start with the fact that it can be divided into three subsystems: the first is aiming for the supply of fuel, the second is for suction of the air, but the third is an electronic control system.
The structural parts of the fuel supply system are the fuel tank, the fuel pump feeding the fuel line (guiding from the distributor for fuel), fuel injector, fuel pressure regulator and reverse fuel line. The principle of operation of the system is as follows: With the help of an electric fuel pump (placed inside or next to the fuel tank), gasoline leaves the tank and fed to the nozzle, and all contaminants are filtered with a powerful built-in fuel filter. The part of the fuel that was not directed through the nozzle into the suction pipe, returns to the tank through the return fueling. Maintaining permanent fuel pressure provides a special regulator responsible for the stability of this process.
The air suction system consists of a throttle valve, a suction manifold, air purifier, an inlet valve and air intake chamber. The principle of its action is: with an open throttle valve, air flows pass through the cleaner, then through the air flow meter (they are equipped with a type L system), a throttle valve and a qualitatively tuned intake nozzle, after which they fall into the intake valve. Air directional function in the engine requires drive. In the course of the opening of the throttle valve, a significantly larger amount of air falls into the engine cylinders.
In some power units, two different methods of measuring the volume of incoming air flows are used. For example, when using the EFI system (type D), the air flow is measured using a pressure monitoring in the suction collector, which is indirectly, while a similar system, but already type L makes it directly using a special device - air flow meter.
The electronic management system includes the following types of sensors: Engine, electronic control unit (ECU), fuel injector devices and appropriate wiring. With the help of the specified block, by monitoring the sensors of the power unit, the exact amount of fuel supplied to the nozzle is determined. To supply air / fuel to the engine in the appropriate proportions, the control unit launches the operation of the nozzles for a specific period of time, which is called the "injection width" or "injection duration". If you describe the main mode of operation of the electronic fuel injection system, taking into account the already named subsystems, it will have the following form.
Finding into a power unit through the air absorption system, air flows are measured using a flow meter. When the air turns out to be in the cylinder, it is mixed with fuel, in which the work of fuel injectors (located behind each intake collector) is played in the latter role. These parts are peculiar electroclapanes that are controlled by an electronic unit (ECU). It sends certain pulses to the nozzle, using for this to turn on and off its grounding chain. When it is turned on, the discovery occurs and the fuel is sprayed on the back of the wall of the inlet valve. If the air is seized outside, it is mixed with it and evaporates due to the low pressure of the suction manifold.
The signals sent by the electronic control unit provide this level of fuel supply, which will be sufficient to achieve the perfect ratio of air / fuel proportions (14.7: 1), called yet stoichiometry.
It is the ECU, based on the measured air volume and motor revolutions, determines the main volume of injection. Depending on the operating conditions of the engine, this indicator may vary. The control unit tracks such replaceable values \u200b\u200bas the engine speed, the temperature of the toosol (coolant), the oxygen content in the exhaust gases and the angle of the throttle, in accordance with which the injection is adjusted, which determines the final amount of fuel injected.
Of course, the power supply system with electronic dosing fuel exceeds the carburetor nutrition of gasoline engines, so there is nothing surprising in its wide popularity. Gasoline injection systems, due to the presence of a huge number of electronic and movable precision elements, are more complex mechanisms, therefore, require a high level of responsibility in the approach to the service issue.
The existence of the injection system makes it possible to more accurately distribute fuel through the motor cylinders. This became possible, thanks to the absence of additional resistance to the airflow, which the carburetor and difsors were created on the inlet. Accordingly, the increase in the filling coefficient of cylinders does not directly affect the increase in the power level of the engine. Let us now consider in more detail all the positive points of using the fuel electronic injection system.
2. Pros and cons of electronic fuel injection
To the positive moments should include:
The possibility of a more uniform distribution of fuel-air mixture. Each cylinder has its own nozzle that feeds the fuel directly to the inlet valve, which avoids the need to feed through the suction collector. This contributes to the improvement of its distribution between the cylinders.
High precision control of air and fuel proportions, regardless of engine operational conditions. With the help of a standard electronic system, an accurate proportion of fuel and air enters the engine, which significantly improves the road quality of the vehicle, fuel efficiency and control over the exhaust gases. Improving the performance of the throttle. Due to the supply of fuel directly to the rear wall of the intake valve, it is possible to optimize the operation of the suction manifold, thereby increasing the speed of the air flow through the inlet valve. Due to such actions, the torque and working efficiency of the throttle are improved.
Improving fuel efficiency and improved exhaust toxicity control.In engines equipped with EFI system, enriching the fuel mixture with a cold start and widely open throttle, is reduced, since the mixing of fuel is not problematic action. Due to this, it is possible to save fuel and improved exhaust controls.
Improving the operational qualities of the cold engine (including launchers). The possibility of fuel injection immediately on the inlet valve, in combination with an improved spray formula, accordingly increases the launch and operational possibilities of the cold motor. Simplification of mechanics and reduced sensitivity to adjustment. With a cold start or measuring fuel, the EFI system does not depend on adjusting the enrichment of the fuel mixture. And since, from a mechanical point of view, it is characterized by simplicity, then the requirements for its maintenance are reduced.
However, no mechanism may have exceptionally positive qualities, therefore, in comparison with the same carburetor engines, the motors with an electronic fuel injection system have some disadvantages. The main one includes: high cost; almost complete impossibility of repair actions; high requirements for fuel composition; A strong dependence on power sources and the need for a constant presence of voltage (a more modern version that is controlled by electronics). Also, in the event of a breakdown, it will not work out without specialized equipment and highly qualified personnel, which is expressed in too expensive maintenance.
3. Diagnostics of the causes of the fuel electronic injection system
The emergence of malfunctions in the injection system is not a rare phenomenon. Especially relevant this question is for the owners of old car models, which more than once had to face both the usual clogging of injectors and more serious problems in terms of electronics. The causes of faults often arising in this system may be very much, but the most common among them are the following:
- defects ("marriage") of structural elements;
The boundary service life of parts;
Systematic violation of the rules of operation of the car (the use of low-quality fuel, system contamination, etc.);
External negative effects on structural elements (moisture getting, mechanical damage, oxidation of contacts, etc.)
The most reliable way to determine is computer diagnostics. This type of diagnostic procedure is based on automatic fixing the deviations of the system parameters from the established norm values \u200b\u200b(self-diagnostic mode). Detected errors (inconsistencies) remain in the memory of the electronic control unit in the form of so-called "fault codes". To carry out this method of research, a special device is connected to the diagnostic connector of the block (personal computer with a program and a cable or scanner), whose task is to read all existing fault codes. However, according to - In addition to special equipment, the accuracy of the results of a computer diagnosis will depend on the knowledge and skills of the person who conducted it. Therefore, to trust the procedure only by qualified employees of special service centers.
In the computer check of electronic components of the injection systemt:
- diagnostics of fuel pressure;
Check all the mechanisms and nodes of the ignition system (module, high-voltage wires, candles);
Checking the tightness of the intake manifold;
Fuel mixture composition; evaluation of the toxicity of exhaust gases on CH and CO);
Diagnostics of signals of each sensor (using the method of reference oscilograms);
Checking cylindrical compression; Monitoring the timing of the timing belt position and many other functions that depend on the model of the machine and the capabilities of the diagnostic apparatus.
Conducting the specified procedure. If you want to find out if there are faults in the electronic feed system (injection) of fuel and if there is, which. The EFI electronic unit (computer) "remembers" all the faults only while the system is connected to the battery if the terminal is disconnected - all information will disappear. So it will be, even until the moment when the driver does not turn on the ignition and the computer does not verify the performance of the entire system.
On some cars equipped with the electronic fuel system (EFI), there is a box under the hood, on the cover of which you can notice the inscription "Diagnosis". It is still tested pretty thick harness of different wires. If you open the box, then the conclusions marking will be visible from the inside of the cover. Take any wire and close the conclusions with it. "E1" and "Te1", then sit behind the wheel, turn on the ignition and observe the reaction of the "Check" light bulb (engine is depicted on it). Note! The air conditioner must be in the off state.
As soon as you turn the key in the ignition lock, the indicated light will flash. If it "blinks" 11 times (or more), after an equal period of time, it will mean that there is no information in the memory of the on-board computer and with a trip to the full diagnostics of the system (in particular, the electronic fuel injection) can be closed. If the outbreaks are at least somehow different - it means you should turn to specialists.
This method of "home-made" mini-diagnostics is available not to all owners of vehicles (mostly foreign cars), but who has such a connector, in this regard is lucky.
In each modern car there is a fuel supply system. Its purpose is to supply fuel from the tank into the engine, its filtration, as well as the formation of a combustible mixture, followed by its entry into the Cylinder Cylinders. What are the views of the SPT and what is their differences - we will tell about this below.
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General
As a rule, most of the injection systems are similar to each other, the fundamental difference may be in the mixture formation.
The main elements of fuel systems, regardless of the gasoline or diesel engines in question:
- The tank in which fuel is stored. The tank is a container equipped with a pumping device, as well as a filtering element for cleaning fuel from dirt.
- Fuel highways are a set of nozzles and hoses designed to supply fuel from the tank into the engine.
- The mixing assembly unit intended for the formation of a combustible mixture, as well as its further transmission to the cylinders, in accordance with the tact of the operation of the power unit.
- Managing module. It is used in injection motors, it is due to the need to control various sensors, valves and nozzles.
- Pump itself. As a rule, submersible options apply in modern cars. Such a pump is a small in size and power of an electric motor connected to a liquid pump. The lubricant of the device is implemented by fuel. If there will be less than five liters of fuel in the gas tank, it can lead to a motor breakage.
SPT on the motor ZMZ-40911.10 Features of fuel equipment
In order for the exhaust gases less contaminated the surrounding among, cars are equipped with catalytic neutralizers. But over time, it became clear that their use is appropriate only if a high-quality combustible mixture is formed in the engine. That is, if there are deviations in the formation of the emulsion, the efficiency of using the catalyst is significantly reduced, that is why over time, car manufacturers switched from carburetors to injectors. Nevertheless, their effectiveness was also not particularly high.
In order for the system to automatically adjust the indicators, the control module was subsequently added to it. If, in addition to the catalytic neutralizer, as well as the oxygen sensor, the control unit is used, it issues quite well indicators.
What advantages are characteristic of such systems:
- The possibility of increasing the operational characteristics of the power unit. In proper operation, the engine power may be higher than 5% of the manufacturer.
- Improving the dynamic characteristics of the car. Injector motors are sufficiently sensitive in relation to the change in loads, so they can independently adjust the composition of the combustible mixture.
- The combustible mixture formed in the correct proportions will be able to significantly reduce the volume, as well as the toxicity of exhaust gases.
- Injector motors, as practice showed, are perfectly launched under all weather conditions, unlike carburetors. Of course, if it comes to the temperature of -40 degrees (the author of the video is Sergey Morozov).
Device injector fuel supply system
Now we suggest familiarizing yourself with the Injector SPT device. All modern power units are equipped with nozzles, their number corresponds to the number of cylinders installed, and together these parts are connected using the ramp. The fuel itself is contained under low pressure, which is created through a pumping device. The volume of incoming fuel depends on how long the nozzle is open, and this, in turn, is controlled by the control module.
To adjust the block receives readings from various controllers and sensors located in different parts of the car, we suggest familiarizing with the main devices:
- Flow meter or DMRV. Its purpose is to determine the source of the engine cylinder with air. If there are problems in the system, its readings of the control unit ignores, and the usual data from the table uses to form a mixture.
- DPDZ - throttle positions. Its purpose is to reflect the load on the motor, which is due to the position of the throttle, motor turnover, as well as cycular filling.
- Duck. The antifreeze temperature controller in the system allows you to implement the fan control, as well as adjust the fuel and ignition. Of course, all this adjusts the control unit based on the Dzhtniki.
- DPKV - the position of the crankshaft. His appointment is to synchronize the operation of the GTT as a whole. The device calculates not only the revolutions of the power unit, but also the position of the shaft at a certain point. In itself, the device refers to the polar controllers, respectively, its breakdown will lead to the impossibility of the operation of the car.
- Lambda probe or. It is used to determine the volume of oxygen in exhaust gases. The data from this device comes to the control module, which, based on them, adjusts the combustible mixture (by video author - avto-blogger.ru).
Types of injection systems on gasoline engine
What is jetronics, what are the types of SPT gasoline engines?
We offer to familiarize yourself with the question of varieties:
- SPT with central injection. In this case, gasoline supply gasoline is implemented thanks to the nozzles in the intake manifold. Since the nozzle is used only one, such SPTs are also called the Moomprosis. Currently, such SPTs are not relevant, therefore, in more modern cars, they simply are simply provided. The main advantages of such systems include simplicity of operation, as well as high reliability. As for minuses, this is a reduced motor environment, as well as a rather high fuel consumption.
- SPT with distributed injection or k-jetronics.In such nodes, gasoline is provided separately to each cylinder, which is equipped with a nozzle. The combustible mixture itself is formed in the intake manifold. To date, most of the power units are equipped with such a SPT. Their main advantages include fairly high ecology, an acceptable consumption of gasoline, as well as moderate requirements in relation to the quality of gasoline consumed.
- With immediate injection. This option is considered one of the most progressive as well as perfect. The principle of operation of this PT is in direct gasoline injection into the cylinder. As the results of numerous studies show, such PTA make it possible to achieve the most optimal and qualitative composition of the fuel and air mixture. Moreover, at any stage of the operation of the power unit, which makes it possible to significantly improve the combustion procedure of the mixture and increase the efficiency of the engine and its power in many respects. Well, of course, reduce the amount of exhaust gases. But it must be borne in mind that such SPTs also have their drawbacks, in particular, a more complex design, as well as high requirements for the quality of gasoline used.
- SPT with combined injection. This option is, in fact, the result of the combination of SPT with distributed and direct injection. As a rule, it is used to reduce the amount of toxic substances dropped into the atmosphere, as well as exhaust gases. Accordingly, it is used to increase engine environmental readings.
- L-jetronics system still used in gasoline engines. This is a paired fuel injection system.
Photo gallery "Varieties of gasoline systems"
Types of diesel engine injection systems
The main types of SPT in diesel engines:
- Pump-nozzle. Such SPTs are used to feed, as well as the further injection of the formed emulsion under high pressure using pump-nozzles. The main feature of such PT is that the pump-nozzles perform the options for pressure formation, as well as directly injection. Such PTTs also have their drawbacks, in particular, we are talking about a pump equipped with a special drive of a constant type from the distribution shaft of the power unit. This node is not turned off, respectively, it contributes to increased wear of the structure as a whole.
- It is because of the last disadvantage that most manufacturers prefer PT type Common Rail or battery injection. This option is considered more perfect for many diesel units. SPT has such a name as a result of using the fuel frame - the main element of the structure. The ramp is used one for all nozzles. In this case, the fuel supply is carried out to the nozzles from the ramp itself, it can be referred to as an increased pressure battery.
Fuel supply is carried out in three stages - preliminary, main, as well as additional. Such a distribution makes it possible to reduce the noise and vibration during the operation of the power unit, to make it work more efficient, in particular, we are talking about the process of igniting the mixture. In addition, it also allows and reduce the amount of malicious emissions into the environment.
Regardless of the type of SPT, diesel units are also controlled using electronic or mechanical devices. In mechanical versions of the device control the level of pressure and volume of the components of the mixture and the moment of injection. With regard to electronic options, they allow you to provide more efficient control of the power unit.
With direct injection (also used the term "straight injection", or GDI) began to appear on cars not so long ago. However, technology is gaining popularity and is increasingly found on motors of new cars. Today we will try to answer what technology is direct injection and should it be feared?
First, it is worth noting that the main distinguishing feature of the technology is the location of the nozzles that are placed directly in the head of the cylinder block, respectively, and the injection under huge pressure occurs directly to the cylinders, unlike the well-proven fuel at the intake manifold.
The direct injection was first tested in serial production by the Japanese automaker Mitsubishi. Operation showed that among the advantages the main advantages were economy - from 10% to 20%, power - plus 5% and environmental friendliness. The main minus - the nozzles are extremely demanding on the quality of the fuel.
It is also worth noting that a similar system has been successfully established for many decades. However, it was on gasoline engines that the use of technology was associated with a number of difficulties that have not yet been completely resolved.
In the video from YouTube-channel SavageGeese, explains what direct injection is and what can go wrong during the operation of the car with this system. In addition to the main pluses and minuses, the videos also explain the subtleties of preventive maintenance of the system. In addition, the topic of injection systems into intake channels are addressed in the roller, which can be observed in older engines, as well as, which use both fuel injection methods. Visually using Bosch charts, the lead explains how it all works.
To find out all the nuances, we suggest watching the video below (the inclusion of subtitle translation will help to figure it out if you do not know English very well). For those who are not too interested to watch, the main pluses and cons of the direct gasoline injection can be found below, after the video:
So, environmental friendliness and economy - good goals, but what is fraught with the use of modern technology in your car:
Minuses
1. Very complicated design.
2. Hence the second important problem. Since young gasoline technology implies a major change in the design of the engine cylinder heads, the design of the nozzles themselves and the associated change in other parts of the motor, for example, the TNVD (high-pressure fuel pump), the cost of vehicles with direct fuel injection higher.
3. The production of the power system itself should also be extremely accurate. Injectors develop pressure from 50 to 200 atmospheres.
Add to this the operation of the nozzle in the immediate vicinity with the combustible fuel and pressure inside the cylinder and get the need to produce very high strength components.
4. Since nozzles are looking into the combustion chamber, all gasoline combustion products are also deposited on them, gradually scoring or output noness. This is perhaps the most serious minus use of the GDI design in Russian realities.
5. In addition, it is necessary to monitor the engine status very carefully. If there is a waste of oil in the cylinders, the products of its thermal decay will quickly dissemble the nozzle, clog the inlet valves, forming an implanial flare from deposits on them. Do not forget that the classic injection with nozzles located in the intake manifold well purifies the inlet valves by washing them under pressure fuel.
6. Dear repair and the need for preventive service, which is also not cheap.
In addition, it also explains that in improper exploitation on vehicles with direct injection, valve pollution and deterioration in performance can be observed, especially on turbocharged engines.
Modern cars are equipped with different systems with fuel injection. In gasoline engines, a mixture of fuel and air is forcibly flashed with a spark.
The fuel injection system is an integral element. The nozzle is the main work element of any injection system.
Gasoline engines are equipped with injection systems that differ in each other by the formation of a mixture of fuel with air:
- central injection systems;
- systems with distributed injection;
- systems with direct injection.
The central injection, or otherwise it is called monojetronic (monojetronic), is carried out by one central electromagnetic nozzle, which injected fuel into the intake manifold. This is something like a carburetor. Now cars with such an injection system are not produced, since the car with such a system also has the low ecological properties of the car.
The distributed injection system was constantly improved over the years. The beginning put the system K-jetronic. Injection was mechanical, which gave him good reliability, but the fuel consumption was very high. The fuel was not impulsed, but constantly. System has come to replace this system KE-JETRONIC..
It did not differ in principle from K-jetronicBut an electronic control unit (ECU) appeared, which allowed slightly reduced fuel consumption. But this system did not bring the expected results. A system has appeared L-Jetronic..
In which the ECU perceived the signals from the sensors and sent the electromagnetic pulse to each nozzle. The system has good economic and environmental indicators, but the designer did not stop on it, and developed a completely new system. Motronic.
The control unit began to control the fuel injection and the ignition system. The fuel has become better to burn in the cylinder, the engine power has increased, the flow rate and harmful emissions of the car decreased. In all these systems, the injection presented above is carried out by a separate nozzle on each cylinder in the intake manifold, where the formation of a mixture of fuel with air, which falls into the cylinder.
The most promising system today is a system with direct injection.
The essence of this system is that the fuel is injected immediately into the combustion chamber of each cylinder, and is already mixed with air. The system determines and supplies the optimal composition of the mixture into the cylinder, which provides good power at various modes of engine operation, good efficiency and high ecological engine properties.
But on the other hand, the engine with this injection system has a higher price compared to their predecessors, due to the complexity of its design. Also, this system is very demanding of the quality of the fuel.
