DIY bosch diesel injector repair

In detail: DIY bosch diesel injectors repair from a real master for the site my.housecope.com.

Although modern diesel engines are becoming more and more complex, the Common Rail system appears to be technically even simpler than the previously used mechanical injection pump systems. Ultimately, the Common Rail system completely replaced competing solutions from the market, for example, with unit injectors.

Various concepts.

Several types of Common Rail systems are used in passenger cars. Simplistically, they can be divided into two types (electromagnetic and piezoelectric) and four manufacturers (Bosch, Continental, Delphi, Denso). Bosch, Delphi and Denso are renowned manufacturers of automotive electronics. Bosch has been developing injection systems at the very beginning of the last century. Delphi bought diesel injection technology from Lucas. The Japanese Denso has gained experience working with Bosch and Magnetti Mareli. Continental acquired Siemens and VDO, becoming the main competitor of German Bosch. The injectors of this company have been marked with the Continental emblem for about a year, previously they bore the Siemens logo.

The most versatile is the market leader Bosch, which produces both types of injectors: electromagnetic and piezoelectric. On a much smaller scale, both types of injectors are produced by Delphi and Denso. Continental (Siemens) is exclusively limited to piezoelectric technology.

Each sandpiper praises its swamp.

In advertising brochures, each manufacturer praises their product as the best solution. As you may have guessed, in practice, many of them often have a number of shortcomings. The simplest design is provided by Bosch electromagnetic injectors. Repair of German injectors is not difficult. Delphi wanted to go further and developed a much more sophisticated control system for its solenoid injectors. As a result, his product turned out to be the most sensitive to fuel quality and, unfortunately, not very durable. Among the electromagnetic injectors, Denso is considered the most reliable, but there are difficulties with the availability of spare parts for repair. The most balanced are the piezoelectric injectors designed by Bosch and Siemens (Continental), and also partly by Denso. The injectors are similar to each other, both technically and in terms of reliability. Only Delphi stands out from this group, whose piezo injectors were reputed to be less hardy throughout the entire time.

Video (click to play).

Whose injectors can be repaired?

From the point of view of the possibility of repair, the most preferable are turbodiesels with classic Common Rail injection from Bosch. Almost all specialized centers can handle the restoration of this type of injectors. But the end result depends on the diligence and honesty of the master. Delphi electromagnetic injectors are also repairable, but require replacement of the tip and injector coding after repair. This increases the cost of repairs, but without coding, the engine will run intermittently. Denso solenoid injectors are among the most durable, but repairs are only possible with spare parts available. But with this, just not all is well.

Delphi and Bosch piezo injectors are considered non-repairable. In the case of Siemens (Continental), injection tips have appeared, allowing you to change the size, which allows you to restore the injector to work. However, this only applies to some models with PSA 2.0 HDI 16V engines. Various modifications of this turbodiesel are used in Ford Mondeo IV, Focus, Galaxy, S-Max and Volvo S40, S60 cars.

What to look for?

The advantages and disadvantages of injectors should be known even at the stage of choosing a car. Considering the risk of injector failure, two models with the same engine should be avoided like fire: Ford Mondeo III 2.0 TDCi and Jaguar X-Type 2.0 d. The injectors of the Mercedes E250 CDI W212 of the beginning of production also had congenital defects. The rest of the cars with Delphi injectors raises no objections. Some motors allow the use of injectors from different manufacturers. For example, the 1.6 HDi / TDCi engine had four different types of injection systems, with Bosch being the cheapest to maintain.The situation is similar with 2.0 HDi. Siemens (Continental) injectors can be refurbished, but Bosch piezo injectors cannot.

What you need to know about injectors Common Rail.

Bosch electromagnetic injectors.

They are disassembled and relatively easy to repair. The cost of restoring one injector is about $ 100-150 per piece. They can withstand 200,000 km. In Opel's 1.9 CDTi and Fiat's 1.9 JTD, the injectors are capable of surviving up to 500,000 km. The price of a new nozzle is about $ 250-300 per piece.

Alfa Romeo 159 2.0 JTDM, Fiat Punto 1.3 JTD, Kia CEE'D 1.6 CRDi, Mercedes C 220 CDI W202, Opel Vectra C 1.9 CDTI, Renault Laguna II 1.9 DCI, Volvo V70 D5, BMW 320d E46.

Delphi electromagnetic injectors.

Compared to Bosch, Delphi injectors are much more sensitive to fuel quality. They are slightly more expensive to repair - around $ 150-200 apiece - due to the need to code with a new tip. Average service life is 150,000 km. The cost of a new nozzle is about $ 250.

Dacia Logan 1.5 DCI, Ford Focus 1.8 TDCi, Renault Megane II 1.5 DCI Nissan Almera 1.5 DCI, Hyundai Santa Fe 2.2 CRDi, Kia Carnival 2.9 CRDi, Ford Mondeo 2.0 TDCi III.

Denso electromagnetic injectors.

Denso electromagnetic injectors are considered to be of the highest quality. Until recently, there was a shortage of spare parts, but nowadays most of them can be restored. The cost of repairs is about $ 150-250 per unit. The price of a new nozzle is about $ 450.

Mazda 6 2.0 CD, Nissan Pathfinder 2.5 DCI, Opel Corsa 1.7 CDTI, Mitsubishi Pajero 3.2 DI-D II, Toyota Avensis 2.0 D-4D.

Continental piezoelectric injectors (Siemens).

Previously offered under the Siemens name, and now Continental. They are durable, but until recently were considered non-repairable. Spare parts appear today, and some workshops take on repairs. The resource of injectors is more than 200,000 km. The cost of a new nozzle is about $ 350.

Citroen C5 2.0 HDi II, Mercedes C220 CDI W204, Volvo V50 D4, Peugeot 207 1.4 HDi.

Bosch piezoelectric injectors.

They are found in many modern cars and are structurally very similar to Continental injectors. They also have a similar resource - more than 200,000 km. Unfortunately, they are not repairable. New ones cost about $ 300.

Audi A6 3.0 TDI, BMW 320d E90, Nissan Qashqai 2.0 DCI, Skoda Octavia III 2.0 TDI.

Denso piezoelectric injectors.

They are quite reliable, but not collapsible and therefore cannot be repaired. They are used in a small number of cars. Most often they can be found in Lexus and new Toyota models. The cost of a new nozzle is about $ 500.

Lexus IS 2.2D, Toyota RAV-4 IV 2.2 D-4D.

Piezoelectric injectors - Delphi.

The market is limited. Debuted with the Mercedes E250 CDI BlueEFFICIENCY in 2009 and started causing problems immediately. Later the design of the nozzles was changed.

Mercedes E 250 CDI Bluefficiency.

Injection system malfunctions Common Rail.

As a rule, the Common Rail injection system is able to hold out more than 200,000 km without any problems. But it all depends not only on the design, but also on the operating conditions. The least reliable and most sensitive to fuel quality are Delphi injectors. The first problems sometimes appear already at 140,000 km. The most hardy is Denso's products. Piezoelectric injectors from Bosch and Continental (Siemens), as a rule, can withstand more than 200,000 km. Bosch electromagnetic injectors serve the same amount of time.

Typical Symptoms of Injection System Malfunctions Common Rail:

- uneven engine operation;

- increased fuel consumption;

However, common rail malfunctions are not always the result of damaged injectors. The defect could overtake the high pressure pump, fuel pressure regulator and other sensors. In any case, the parameters of the injection system give an almost accurate answer to the question of the condition of the injectors.

What not to do in the garage.

It is possible to "examine" the system using a special diagnostic computer using the pressure parameters and the so-called "injector correction". Another easy way is to determine the amount of overflow. It is also possible to remove the nozzles for inspection or testing at the stand. Unfortunately, in some cases it is impossible to remove the nozzle - it sticks.

How to renovate.

Technical capabilities allow restoring all electromagnetic injectors (Bosch, Delphi, Denso). Limitations may be imposed by the availability of spare parts: valves, tips, coils, housings, etc.). In the case of Bosch, there are no problems. Slightly worse with Delphi components. And for Denso, the original components simply do not exist. There are only a small percentage of unofficial substitutes.The cost of refurbishment depends on the number of replaced elements and the manufacturer of the injectors. For Bosch, the approximate amount will be from $ 50 to $ 150 per piece, and for Delphi and Denso - up to $ 200-250.

Complete restoration of Bosch, Delphi and Denso piezoelectric injectors is not possible. All that is permissible is to remove the nozzle tip, rinse it in an ultrasonic apparatus and check the operation of the nozzle on the bench.

The situation is slightly better with some Continental (Siemens) injectors. Spare parts are available for individual injectors. The restoration cost is about $ 150.

Disassembly and repair of injectors should be carried out only by specialists of specialized services. Dismantling the nozzle itself requires a special tool. In addition, before and after parsing, it is necessary to check the operation of the injector on a special stand.

- checking the nozzle at the stand;

- dismantling and flushing of elements;

- troubleshooting and replacement of necessary parts;

- adjustment and assembly of the nozzle;

- measurement of parameters after assembly;

- assignment of an individual code, taking into account the characteristics of a particular instance (for some injectors).

Only after the regeneration process and the elimination of related malfunctions (for example, sediment in the tank or chips from the pump in the system), the nozzles can be installed back into place. Along the way, the fuel filter and copper washers under the injectors must be replaced.

In the context of general progress, diesel vehicles are in great demand. Modern diesel engine configurations characterize Common Rail fuel systems. Its high performance and environmental friendliness have been confirmed by more than one study. High-quality repair of nozzles of this sample is not an easy task that real professionals are capable of performing.

The injector itself is a solenoid valve. Its purpose: injecting a metered amount of fuel required to prepare a combustible mixture under conditions of various operating modes of diesel engines. The amount of fuel supplied to the coil of the injector electromagnet depends on the duration of the electrical impulse. In the engine cylinder itself, fuel injection by the injector is synchronized with the position of the piston.

The start of the injection process involves the initial lift of the needle, which is responsible for the supply of a small amount of fuel to the combustion chamber. A further increase in the injection pressure raises the injector needle completely, thus the main injection proceeds.

The task of two-stage injection is to provide a softer combustion process and reduce noise.

Bosh, a leader in the production of diesel fuel devices, has developed the Common Rail system. Its main feature is the injection pressure up to 2500 kgf / cm2, the maximum value of which is created not in the accumulator, but in the nozzle itself. Common Rail is equipped with:

miniature hydraulic pressure booster;
two solenoid valves, allowing to vary within one working cycle from the amount of fuel to the moment of injection.

Fuel injectors and repair kits of another model from this company have a device in the form of a small pressure reservoir, the task of which is to reduce the return stroke to the low pressure cycle. As a result, injection pressure and system efficiency are increased.

Directly at the factory, every Bosch diesel injector body and repair kit undergoes a trial period. In addition, they are subjected to increased stress in order to minimize the likelihood of breakage. In practice, manufacturer parts have the exceptional precision of sprayers in both trucks and light vehicles.

Use the services of professional companies if you observe:

an increase in fuel consumption with the condition of the previous operating mode;
the appearance of increased smoke and extraneous noise;
decrease in diesel power;
difficulty starting the engine.

The use of low-quality fuels and engine oils in most cases is the main factor in the failure of injectors. The entire fuel system can fail through impurities or water in the fuel. The fact is that the minimum volume of water under high temperature and pressure conditions easily disables the injectors and the repair kit, which are responsible for fuel injection and atomization. The final diagnosis: repair is required, or replace the repair kit.

Before starting the repair, make sure that the service center meets the requests:

All the necessary equipment and tools for diagnostics and adjustment are available.
The company employs only experienced, qualified specialists.
The manipulations are carried out in accordance with the recommendations of the manufacturers.
Testing on special test benches is provided.
Repair of parts is accompanied by a multi-stage quality check, which is carried out by several specialists.
A guarantee is issued for the work performed.

In diesel vehicles, injectors play the role of an important functional unit. Repairs and their quality are responsible for the continued efficiency of the entire system. As a rule, before this it is necessary to carry out computer diagnostics, the correctness of which will serve as the key to a successful resolution. The main task of this stage is to identify the true cause of poor engine performance before removing the injectors.

Based on the results obtained, experienced specialists already have a rough idea. A neglected state implies a total repair, or there may be minor malfunctions that a new repair kit will solve.

The final diagnostics shows the compliance of the manufacturer's initial data in the parameter adjustment:

fuel atomization quality;
injection start pressure;
reverse leakage;
tightness of the shut-off body;
mechanical wear of the sprayer, etc.

Since the injectors and its repair kit are the most vulnerable point, routine diesel diagnostics are recommended for diesel car owners. Thus, we extend their service life.

Diesel engine repair is a complex type of work. It is important to eliminate all problems that are associated not only with the operation of diesel injectors, but also with other types of injection through them.A diesel engine is highly susceptible to low-quality fuel or oils. This factor often becomes the cause of the malfunction. Cleaning parts with special equipment is also a repair. In this case, you may need a new repair kit, as some parts may fail in time.It is important to know the manufacturer of these elements, the maintainability of which is determined on the basis of the endowed characteristics. For example, diagnostics at the stand showed a violation of the bosh79 spray torch. In this case, both the nozzle and the atomizer itself need to be replaced.The same manufacturer offers a special repair kit that includes O-rings. Damage or wear will also negatively affect the functionality of the diesel system. A complete restoration of the injectors is necessary if a component breaks down, which cannot be repaired.

Image - DIY bosch diesel injector repair

Anchor. There is nothing to break in it, you can only lose.

Ball. When assembling, the injector must be replaced with a new one.

Cartoonist. The main component that most often fails and must be replaced or restored. We change to new original ones, as this is the most reliable and high-quality repair option.

Spray. On Common rail injectors, the sprayer rarely fails. On average, it serves 150-200 thousand km, with a higher mileage it must be replaced, with a smaller one - cleaning in an ultrasonic bath.

Frame. Most often it fails when the injector is removed from the engine. It is diagnosed visually for the absence of cracks and deformations. You can replace it with a used one, if available, or order a new one.

The main problem after repairing injectors is incorrect installation on the car. When installing the injector, it is imperative to pump fuel through the injection pump to the injectors so that there are no air bubbles.

Today, the Common Rail system is used in almost all modern cars, regardless of whether they are diesel engines or gasoline ones. There is an explanation for this phenomenon: the system is very efficient and reliable. But not every car enthusiast has a clear idea of how it works when it is necessary to restore or replace parts of this type. And many have a very superficial idea of the repair of injectors in this system. Let's understand these points in more detail.

The Common Rail system is today the latest stage in the development of diesel and gasoline engines with direct fuel injection. A feature of the system is that the injection process and the pressure build-up process in the fuel rail occur separately from each other.

Today the Common Rail fuel system is considered to be the most advanced

That is, at first, high-pressure fuel is accumulated in the rail, and then in portions it is supplied to the nozzles for subsequent atomization in the combustion chambers. The fuel is pumped into the rail by a high-pressure fuel pump (injection pump), and the Common Rail system is controlled by an electronic control unit (ECU).

The main difference between the Common Rail system and gasoline fuel delivery systems is its incredible flexibility. A car enthusiast can very finely adjust both the injection parameters and the pressure level in the fuel rail, depending on the engine operating mode. All that is needed for this is to change the settings of the car's ECU. Changing the settings allows you to meet the ever-increasing requirements for exhaust emissions, engine noise levels and engine efficiency. Gasoline systems cannot provide such flexibility in principle. To change at least one of the above parameters and adjust it to the desired value, the owner of a gasoline engine will have to adjust it for a very long time.

Common Rail uses different types of this type of parts. They differ in both design and performance. Let's list the most popular models.

The vast majority of engines with Common Rail systems use piezoelectric injectors, since they are considered advanced and have many advantages.

As the name implies, the actuator is based on a piezoelectric element. Using such an element has a number of advantages:

an injector with a piezoelectric element switches 8 times faster than analogs based on solenoid valves;
the needle in it weighs 70% less;
such a part can inject fuel several times during one working stroke of the engine;
the fuel injected by it is precisely metered.

Electromagnetic injectors are used primarily in gasoline engines. The needle in it is set in motion with the help of a spring and an electromagnet, and in one working cycle of the engine, the part can produce only one fuel injection. The design of this device can be found in the figure below.

It should be noted that, in terms of fuel metering accuracy, the electromagnetic one is significantly inferior to the piezoelectric one. This indicator directly depends on the type of control system. For example, if a car is equipped with a modern ECU, the accuracy of petrol dosing increases by 10-12%. There is a certain error in the timing of the electromagnetic injectors. For example, a nozzle needle can hold the nozzle port open for 2–2.5 ms with an accuracy of 6%. This figure is far from ideal.

Almost all malfunctions occurring in both diesel and gasoline injectors are associated with clogging. And the question comes down only to how exactly the blockage arose in the sprayer.

The so-called knock is a malfunction resulting from coking of the sprayer holes. The fact is that this part is regularly exposed to high temperatures. If the driver constantly uses low-quality fuel, resinous deposits accumulate on the nozzles.

The common rail injector sprayer is out of order due to low-quality fuel

Gradually, the surface of these deposits becomes covered with solid carbon deposits, and interruptions begin in the fuel supply. It is at this moment that the mechanism begins to "knock". Here are the signs of his knocking:

engine power is significantly reduced;
an increase in engine speed leads to jerks and dips;
at low speeds, the motor is unstable and often stalls;
the toxicity of exhaust gases doubles and sometimes triples.

To eliminate, the device must be rinsed. Here are the main ways to flush:

flushing with special fuel additives;
flushing at the stand (for this, the parts will have to be removed).

A nozzle leak usually occurs due to the destruction of the O-ring underneath. Any, even the smallest crack in this part leads to a leak, since the pressure in the fuel line is very high. In addition, due to the collapsed ring, the fuel system loses its tightness and air begins to leak into the engine combustion chamber.

Due to the destruction of the O-ring, the Common Rail injector may leak

Here are the signs that the injector is leaking:

when examining the engine, characteristic oily streaks are visible around the part;
the engine is very difficult to start;
the running engine works intermittently and characteristic pops.

Diesel injectors are repaired when flushing is ineffective. All repairs, in essence, boil down to replacing the coked sprayer. If the problem persists, the return filter of the part is also replaced. To work, we need the following tools:

repair kit for Common Rail (it consists of a new atomizer and a return filter);
set of open-end wrenches;
special puller for these parts.

The puller is installed on the extractable nozzle. To remove Common Rail injectors, it is best to use a proprietary puller
A rod is inserted into the puller, a nut with a left-hand thread is screwed onto the rod (these rods and nuts are supplied with proprietary pullers). A rod and a nut with a left-hand thread are installed on the Common Rail injector
The nut is loosened with an open-end wrench 36. Together with it, the element being repaired itself is weakened.
Now the part is manually unscrewed from the socket. Pre-weakened Common Rail injector is manually removed
An open-end wrench for 17 is put on it from the side of the filter, a key for 13 is put on the nozzle cover. After that, the key for 17 is held, and the nozzle cover is loosened with another key.
The spray lid, which has been loosened with the keys, is now unscrewed by hand. The cover of the common rail injector nozzle, previously loosened with keys, is unscrewed manually
The old atomizer is carefully removed from the cover and replaced with a new one. The old dirty sprayer is removed from the Common Rail injector
A non-return valve is removed from the second part. The common rail injector check valve can be removed after removing the atomizer
The return spring is removed from the check valve. The return spring of the common rail injector is removed from the check valve
The check valve is replaced with a new one. The removed common rail injector check valve is replaced with a new one from the repair kit
After that, reassembly is performed.

First, we will consider the most acceptable option for a motorist: flushing the injectors without removing them from the car. To carry out this procedure, you will need the following things:

Wynns flushing fluid;
an empty plastic bottle with a capacity of 1.5 liters;
rubber hose 1.5 m long;
2 nipples for car wheels;
automobile compressor;
injector filter, 1 piece;
steel hose clamps, 4 pieces.

Before starting the flushing, you will have to assemble a simple washing device that will work as a dropper for the patient.

If self-cleaning does not give results, then the car owner will have to use the stand. It is not possible to make such equipment in a garage. Therefore, the car owner will have to contact a specialized service center, which has such stands.

BLUSTAR washing stand, used in most modern car services

During bench washing, all parts are removed from the engine, installed on the bench, where they are washed in a special solvent. In addition, they are sonicated. This comprehensive approach ensures the removal of even the most stubborn and stubborn dirt.

Flushing stands for BOSCH nozzles began to appear in services relatively recently.

In most centers, flushing is performed at the stands of BOSCH and BLUSTAR. The cost of bench washing of nozzles varies from 1000 to 1800 rubles.

So, it is quite possible to repair and flush the nozzle yourself, unless the case is difficult. Well, if the contamination turned out to be very persistent and even a high-quality flushing liquid did not take it, there is only one option: to remove the parts and take them to the service center, to the ultrasonic stand.

The injector is the main segment of the diesel engine fuel system.

For motorists, such unfavorable cases are probably known as: increased fuel consumption, low engine power, which are inevitable during vehicle operation.

Saving Is what most diesel motorists look for. However, the high cost of modern elements of diesel power systems is not affordable for everyone.

Delivery of injectors to a diesel service is one of the popular methods for solving the problem. Many motorists do not know how and do not want to repair diesel injectors with your own hands.

In this situation, you will have to pay not a small amount of money. Of course, this method will be the most effective, but sometimes it is impossible to transport a broken car to a maintenance service (for example, when a failure is befallen on the road).

Therefore, we will tell you how to do DIY diesel injector repair without the help of auto mechanics and a big waste of money.

For repairing diesel injectors it must be remembered that with a simple replacement of the nozzle in the nozzle, when you unscrew the desired nut, replace the nozzle and attach the nut back, you directly run the risk of spoiling the nozzles even more and its quality can significantly deteriorate.

Therefore, it is better not to use this method. Manufacturers note that changing nozzles is optimal on average every 100,000 - 15,000 km. It should be noted that the most common causes of injector malfunction are: wear, corrosion or contamination.

It is important to know that the Delphi injector is equipped with designs that are much more reliable and durable compared to the Bosch injector.

For a long time, manufacturers fuel equipment Bosch was not informed about the possible repair of injectors, while only accumulating and collecting them, repaired, and then safely sold.

As a result, the nozzles were expensive and of excellent quality. Then Bosch made the repair information available to everyone, so the service was organized.

The Bosch injector is relatively easy to repair, so you will significantly save your money costs.

It is better to change the nozzles during the repair process, but there are times when cleaning with ultrasound is sufficient.

When repairing Bosch diesel injectors, it is necessary to start the movement of the ball and the electromagnet.

The clearances are adjustable due to the functioning of the washers. The movement of the ball is approximately 0.03-0.07 mm (it depends on the nozzle model). Then, based on the test plan, the stroke of the electromagnet is established. It should be noted that without professional equipment, it will be much more difficult to make the adjustment correctly.

Delphi injectors used by most of both cars and trucks.

Let's immediately establish that the Delphi injector is more difficult to repair. In this case, you will have to change 2 main components: valve and atomizer, but it's not so easy to get them, you have to order.

The peculiarity is that you will significantly save on repairs, since the average cost of a nozzle is almost 2 times higher than its repair, after which the nozzle will work like new.

Most often, the valve itself fails, there is a turntable in it, moving up and down, thereby blocking the channels. In most cases, the spraying is deformed on it, the turntable may become out of place, as a result, it does not function as before and the nozzle is drained into processing and the valve becomes defective.

It is important to know that Delphi is equipped with designs that are reliable and durable several times compared to the Bosch injector.

Summing up, we note that when repairing the nozzle with your own hands, you need to look at the company. So, repairing Bosch diesel injectors with your own hands is much easier and faster.

While Delph injectors are time consuming.

Sooner or later, everyone is faced with a significant increase in fuel consumption, a drop in engine power, there are times when the car refuses to move. One way or another, but the problem of the necessary replacement of nozzles may arise. The easiest way is to take the injectors to a diesel service, but then you have to pay a certain amount. There is no need to argue, this will be the most correct method. But the situations are different, for example, 200 km before the service, I think that a broken car will not pass them.But maybe the owner of the car thinks that he will cope with this problem no worse than auto mechanics, besides, he will save money? It was for such cases that the text was written. Also, the text will help you not to make mistakes, having familiarized yourself with it, you will help to abandon this venture in time.So, we are trying to understand the structure of a diesel injector, as well as what is happening there and what affects what. In fig. 1, a shows a cross-section of the nozzle. All injectors (except for ultramodern ones) have a similar structure, the processes that take place in one type of injectors are similar to those that take place in others.As a result, the operation of the engine is hard with shocks, the motor may refuse to accept the load. In addition, the ingress of combustion products into an unlocked system is not excluded, this can become a failure of the sprayer.What then can prevent the normal locking of the system with outwardly intact parts? This can mainly be due to a lateral force that presses the needle against the nebulizer body. This force is fought by the intermediate pusher 10, which unloads the needle from the possible impact of a curved spring. The intermediate pusher is located in the spacer casing 3. But there are also cases when the pusher itself becomes the cause of the lateral force, the cause may be a depletion. That is, when replacing nozzles, you always need to be prepared for the fact that the new nozzle will "pour", if this happens, then you will need to repeatedly overhaul with the spring turning over or with its replacement, or you will have to replace the pusher. In rare cases, even the nozzle body will have to be replaced.Everything else about the injector is pretty simple. Since the needle in the atomizer is not sealed, some of the fuel seeps into the gap between the atomizer body and the needle and enters the cavity “B”, where the spring 9 is located. , the resulting injector is “prohibited”. In order to remove the leaked fuel, the “return” channel is intended. only by the cleanliness of processing and the accuracy of the mating surfaces.So, here we come to the very process of replacing the nozzles. Throughout the presentation, I adhered to the idea that you have a stand or apparatus that can replace it, on which, after the work done, you can test the injectors. With any work related to fuel equipment, it is imperative to observe the main rule - this is cleanliness. Please note that cleanliness should be not only during the direct disassembly of the injector, but at all stages, starting with the dismantling of the injectors from the engine.Then there are only two options for the development of events: in the event that you have not yet replaced the sprayer, then you have deprived yourself of the opportunity to see what was wrong with your old sprayers. Second - you have doomed yourself to cleaning brand new sprayers (this procedure is not always successful). Hence the conclusion - the cavity of the nozzle must always be protected from dust, there is nothing to say about debris. By the way, tobacco crumbs, which are in your pocket in large quantities, have a destructive effect on the nozzle. By the way, it is best to remove the high-pressure pipes in a package together with ties (if the engine design allows it), so during the assembly process you will be less puzzled over how it all stood. For all the simplicity of this problem, thousands of people have suffered due to their negligence. If it is not possible to remove the tubes in a package, then we mark the fitting of the first cylinder on the pump, then mark the tubes themselves in the order in which they stood. As life shows, this can save a huge amount of time and nerves.Removing the “return lines” will not be difficult. True, on cars of Japanese manufacturers, where you have to remove the “return” ramp, before you start to loosen the return nuts, you need to put on protective caps on the fittings. In order to remove the ramp itself, the caps will have to be removed, but then do not forget to put them on immediately.But more often than not, the injectors are screwed into the body of the block head. In order to unscrew them, do not try to use an open-end wrench. Even if you managed to do this without damaging the nozzle without damaging it, I think it will not work to screw it back in without damage, since you will not be able to tighten the nozzle to the right moment. Almost all nozzles have a 24 or 27 hexagon, in order to unscrew them, elongated end heads are quite suitable. It is much more convenient to carry out this work with twelve-sided heads. If it is not possible to purchase elongated heads, you can get out of the situation, in this way: cut off its hexagonal part from the usual head and weld it to a piece of pipe from one end, and from the other end we weld a counterpart for the wrench. The problem has been resolved. It is not necessary to unscrew the nozzles immediately; first, it must be slightly shaken in the thread after being torn off. This is done in order not to instantly spoil the thread in the head or the head itself, since during previous intrusions, dirt could have entered the channel.So, the injectors are removed. Now we immediately begin to remove the sealing washers from the nozzle channels, or rather their remains and debris in general. Removing the washers is often a painful dental procedure. As a rule, normal washers should simply be removed with a hook, but sometimes you have to come up with various individual “pull-outs” for this (for example, screw a tap into them and pull for it). In no case should you try to chop the washer in the channel with a chisel. You will definitely damage the end part of the channel, and correcting such notches will require removing the block head. Trying to solve the problem of a damaged end by installing clever washers, I boldly call it a gamble.Having removed the injectors, first of all, you need to check their performance and make sure that the previous sentence was not erroneous. The main criteria for evaluating the work of sprayers:

when fuel is supplied, the injector must open only at a given pressure;

before the nozzle opens, leakage from the spray is unacceptable;

jets and drops are unacceptable during fuel injection;

the spray torch should be even, there should be no deviations (Fig. 2);

after stopping fuel injection, the injector must maintain pressure for some time.

They also talk about the characteristic sound of the injector operation, however, the sound should not be considered an objective parameter for evaluating the injector, but this parameter should not be ignored either. If it turns out that replacing the nozzles is really necessary, then we put on protective caps on the nozzles and start preparing the workplace. All preparation consists in thorough cleaning and washing of the table and the vice, you will need at least two baths with clean diesel fuel, the necessary keys (usually two) and, perhaps, you will need another knife - all unnecessary will interfere with the work. If you do not have a special device in your garage for fixing the injectors during disassembly. So, you will have to disassemble in a vice. I must say right away that the injectors of Japanese cars, whose “return” flows through the ramp, should never be clamped in a vice, since when clamping the edges of the sealing surface under the “return” they are crushed (Fig. 3).Such injectors can be disassembled by placing them in a spanner wrench, which is clamped in a vice (Fig. 4).But the nozzles of German manufacturers can be disassembled in a vice without harm to health. But you cannot use open-end wrenches to disassemble the injector.To begin with, this is rather inconvenient, but there is also a more important reason, for example, the union nuts of the injector housing of some engines (for example: Mercedes OM601,602,603) almost always crack when trying to assemble or disassemble them with an open-end wrench. And this part is quite expensive, and besides, it is not so easy to buy it. Therefore, for disassembling the injectors, we will use the same extended head as for removing it from the engine. We loosen the tightening of the union nut, then screw it with our hands. Often it can curl up with the spray that has stuck to it. The sprayer, after the nut has been removed, can be knocked out with a suitable rod, and the cavity of the nut can be cleaned with a brush to clean the battery terminals.Of course, to complete this work, you need to move a couple of meters away from the clean area. The nut must be rinsed in the first bath - it will be for dirty deeds, after the nut, we put it to drain to the side on a sheet of paper. Now we begin to remove the intermediate body by rinsing it in a clean bath, drain the nozzle body, which is clamped in a vice, with fuel and put the intermediate body in place, do not touch anything else. We take a new sprayer without disassembling it, rinse it in clean fuel. After rinsing, it is necessary to pull out the intermediate casing or the sprayer (however, like all parts of the fuel equipment) from the tank after rinsing so that the flowing fuel carries away all dust particles from the mating surfaces (Fig. 5 and 6).Thus, the procedure for replacing the sprayer will turn into a series of assemblies-disassembly-checks, you will have to repeat the same operations until you achieve the required result. Finally, we have achieved the desired result, the operation of the injectors suits us and they can be installed on the engine.Before you start screwing in the injectors, you need to make sure, turning the crankshaft with the starter, that no water or other debris has entered the cylinders, and you can also look at the oil dipstick.Re-assembly should not be a hassle, but this is in the event that you did not get excited and, when removing, marked all the pipes and fittings. Just a few tips. Flush the outside and spill fuel on the inside before installing the high pressure pipe. And yes, don't neglect to replace the clamps that collect the tubing into the bag. These clips are not for aesthetics. They prevent vibration from occurring. Tubes without clamps break very quickly (as if cutting them with a knife).Well, everything seems to be, you can expel air from the equipment and try to start the engine. What is the best way to check the performance of the injectors is indisputable, it is best to use a stand for testing injectors, this stand can be the most complicated electronic one for several thousand dollars and very simple, one might even say primitive in the spirit of the fifties (Fig. 7) or homemade (Fig. 7). eight).To do this, you need to make a tube - a tee, one end of which will be connected to one of the high-pressure fittings of the injection pump, on the other end we will attach the nozzle, and on the third we will attach a pressure gauge of 200-300 atmospheres, of course, more is possible, but this one will fit on the edge too. First, we turn the engine with the starter until the nozzle starts firing, and then, without leaving the ignition on, we turn it manually. Of course this is painful, but if there is no other way out, it will do.During the compression stroke, an air charge flows from the cylinder into the combustion chamber at a tremendous speed. In the combustion chamber, due to its shape, at this moment a directed vortex arises, and fuel is injected into this vortex. There are different nozzles and different fuel injection pressures, depending on the compression ratio and the design of the combustion chamber, the shape and speed of the vortex are different. The designers set the recommended allowable injection pressure for each engine.It should be noted the property of rotary-type fuel pumps of the LUCAS company - on these pumps there are strict requirements for the accuracy of the injection pressure regulation within the set of injectors.In engines with such fuel pumps, it is not possible to find a faulty injector using the shutdown method. Since the engine will immediately stall due to the fact that the fuel supply to the remaining injectors stops.In most cases, the opening pressure of modern injectors can be adjusted by adjusting the thickness of the spacer washer between the body and the spring. Good workshops have a set of washers that can solve adjustment problems. But amateurs should know that there are washers of various diameters, they are designed for different nozzle bodies, and are available with or without a hole. Washers without a hole can be replaced with washers with a hole, but must not be replaced. It is also unacceptable to use washers of "non-native" diameter.A distinctive feature of the injectors of Japanese engine manufacturers is the “return” outlet to a special ramp through the end face of the injector. If disassembled carelessly, deformation of the nozzle sealing end will occur; due to deformation of the hermetic return seal, it will not be possible to achieve. Some begin to "experiment" with tightening the ramp nuts and placing sealing washers under the nuts. The only way to solve this problem is to undercut the sealing face of the nozzle on a lathe. But keep in mind that only one face of the nozzle can be corrected by facing, so the shape of the groove on the face may be deformed so much that the sealing washer can no longer cover it. Only change such a nozzle.

Video (click to play).

Silly attempts to tighten the flowing or sweating return lines almost always lead to deformation of the return ramp flanges. Seals cannot be achieved with these flanges; they will have to be repaired. It's quite simple, you can do it by hand with sanded tiles by placing sandpaper on top of them.