Do-it-yourself common rail injector repair pouring into the return line

In pursuit of excellence, you choose the best. AS8 Club - those who have made their choice.

Message POPINS Wed Feb 13, 2013 6:41 am

Message POPINS Wed Feb 13, 2013 8:10 am

After reading and talking with smart people, we got down to work.
Maybe someone will use the principle of work
The report is taken from here: https://my.housecope.com/wp-content/uploads/ext/1427/technics-repa. -cleaning /

Visual video of the operation of Common Rail injectors

Now let's start assembling
If, after assembly, the injectors are not immediately installed in the engine and put into operation, then all parts must be lubricated. Better diesel fuel - their native liquid, if there is no possibility, then at least something, a liquid key, for example. This is to prevent dry parts from rusting inside.

The nozzle is beautifully cleaned and assembled, ready for action. But its exact working condition can be shown by the stand, which I did. Nozzle works like new - stand verdict

As a result, we get a result in monetary terms equal to 4000, or better a new one for 25000

Since nothing lasts forever, some parts of the nozzle may come to an end, for example, the needle may stick in the atomizer and I really don't know how to get it out neatly without damaging it. The valve seat with the ball can wear out, and the multiplier valve can also lose its steam. In this case, it is possible to order spare parts, here are the codes that we can hammer in existential

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.

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.

Cars change, friends and the forum remain. [my.housecope.com/wp-content/uploads/ext/1209]

Message 300ce »25 May 2014, 17:40

Message zsergei »25 May 2014, 18:06

Message schertov »26 May 2014, 10:43

Message Alex_52 »27 May 2014, 17:43

Message okv »27 May 2014, 18:28

Message 300ce »May 29, 2014, 17:54

Message Alex_52 »May 29, 2014, 19:55

Message rz3ok »05 Sep 2015, 11:00

Message chaytan »05 Sep 2015, 20:05

starting pressure approx. 120 bar. below will not start.
in idling mode, the pressure is already from 250 bar. and then, depending on the load, up to 1300 bar.

Added after 2 minutes 34 seconds:

on the air, the engine is started due to the fact that the revolutions have time to rise higher than the starter turns and, accordingly, the pressure in the ramp is created faster and higher.

Added after 7 minutes 12 seconds:

Message rz3ok »20 Sep 2015, 18:56

Message chaytan »20 Sep 2015, 19:14

Message Bronislavovich »20 Sep 2015, 21:49

Message rz3ok »21 Sep 2015, 08:45

Good day to you!
What fright did you get that
rz3ok wrote:
Time to recalculate approximately 2 seconds
I'm a simple best man And these are my observations in the process of driving and how many megahertz there are in January, when minus 30 is overboard and you start to stall under load.

Message Git »21 Sep 2015, 16:36

Message Bronislavovich »21 Sep 2015, 22:26

Hello.
rz3ok, dear, this is called "QUOTATION".I took this not from the ceiling (and certainly not from the fright), but from your message of September 21, 2015, written by you or someone who has the ability to use your account and owns your writing style, at 21 hours 56 minutes. This resource (forum) allows you not even to retype the quoted message, but simply select the desired part and press the "button" with the inscription "QUOTE".

Do you really think it takes a computer 2 seconds to “think over” your pedal stroke? According to your logic, microcircuits work on smoke, because when this smoke comes out of them, they stop working.
The essence of my message is only that by reducing the load on the engine, with stuck fuel equipment, you can avoid constant stalling without resorting to desperate pedaling.
Along the way, I note that if you have no desire to understand the reasons for the untimely death of the injectors, you should pay attention to cars that have that same January as an ECM. By definition, they are much simpler.

Everyone knows that diesel engines are slightly different from gasoline engines in that they have different ignition systems. Therefore, diesel engines do not have a carburetor or an injector; in a diesel engine, in any case, injectors are used to inject fuel into the cylinders. In fact, initially the engine, which ran on diesel fuel, was very dirty, it emitted a lot of harmful gases into the atmosphere, and was also very loud in operation. But such an engine was also very powerful, so it was decided to develop it.

Thus, today diesel engines are already installed not only on trucks, but also on cars, and they are also supplemented with turbines, which give such a motor power. To supply fuel to the combustion chambers, injectors are used, the most popular of which are Common Rail injectors. Therefore, a frequent request in all search engines in this regard is a request for the repair of Common Rail diesel injectors.

Of course, in order not to repair and maintain Common Rail injectors, you need to take care of them. In fact, caring for Common Rail injectors is no different from caring for nozzles of any other company.

You can extend the life of your sprayer by using only quality fuel.

• Therefore, refuel the car only at proven gas stations and only in proven dispensers. Unfortunately, at the same filling station in different dispensers there can be high-quality and low-quality fuel. It all depends not only on what is in the bunker, which is under the refueling, but also on the state of the dispenser itself.
• The second condition that will help extend the life of the sprayer is to change all filters in the car in a timely manner. This must be done because the condition of the spray nozzles directly depends on the condition of the filters. If the filters let through all the debris in the air or fuel, they will instantly clog the jets and have to be cleaned. You can find out how often the filters need to be replaced by reading the instructions for each filter upon purchase.
• In addition, you also need to flush the nozzles with a frequency of 25-30 thousand kilometers by pouring a special agent into the tank.
• The last thing to do to extend the life of Common Rail nozzles, so as not to make repairs ahead of time, is to pay attention to even the smallest changes in the operation of the fuel system and periodically carry out diagnostics.

As already mentioned, it is possible to extend the service life of Common Rail injectors and not make repairs ahead of schedule, if you periodically clean it by adding a special agent to the tank. Such cleaning should be carried out every 25-30 thousand kilometers of distance traveled. If this is not done, then the entire fuel system, including the high-pressure fuel pump, can become unusable.

Many people know that repairing the entire fuel system is very important, because without a working fuel system, a car will not be able to drive. You can do this cleaning of Common Rail injectors with your own hands. The second cleaning step does not require removing them from the machine. In this case, the common rail injectors are cleaned due to the fact that air is blown into them under pressure, which is able to clean the clogged nozzles.

There are such blockages when even the second option does not help, in this case the last stage of cleaning the nozzles will come to the rescue. The cleaning process in the third version is based on the fact that the device is immersed in a special chamber, where, under the influence of ultrasound, all particles that clog the jets are destroyed. The only drawback of this cleaning option is that in this case it will be necessary to remove them from the car and take them to a service station, where they are engaged in such work.

Do not think that you will be able to clean completely clogged nozzles with your own hands. Self-cleaning can completely damage the sprayer, passages, or device body. In this case, a complete replacement of nozzles or even nozzles will be required, which will have a negative impact on the driver's wallet.

Our advice: if you do not have experience in this area, it is not recommended to repair injectors with your own hands.

Today there are two types of Common Rail injectors. The first type is electromagnetic, and the second is piezoelectric. The main difference here is considered only the drive of the needle, which, under pressure, releases fuel into the combustion chamber, where it mixes with the fuel.

Besides that there are two types, Common Rail injectors come from different manufacturers. The main manufacturer is considered to be Bosch. This company received such a calling because it produces both types of this device and has been doing it for many years. Other manufacturers (such as: Delphi or Denso) are engaged in the production of only piezoelectric atomizers and produce them in smaller quantities.

As you know, the quality and service life of the device depends on the manufacturer. The firm, which is considered the main manufacturer, occupies this position not only for the reasons presented above, but also because these atomizers will last longer. The company achieved this result by simplifying the design. In addition to being durable, Bosch sprayers are also easy to repair. At the same time, other manufacturers tried to improve their devices by increasing the complexity of the design. The result is a device that is practically unpretentious in terms of fuel quality, but has a shorter service life, but at the same time they practically cannot be repaired in the event of a breakdown. Each driver has the right to independently choose the brand that he trusts more for objective reasons.

When choosing a nozzle, one must proceed from the information that has already been personally confirmed, namely, which nozzles can be repaired and which cannot. There are a number of factors on the basis of which the final choice can be made. One of these factors is the brand of the engine. This must be taken into account for the reason that the manufacturer expects that he will work only with those devices that are installed by the factory, and not with those that will be installed after repair.

There are a number of faults that occur frequently. The main breakdown of all injectors is considered to be a malfunction of the needle, which, under pressure, injects fuel into the combustion chamber, where it mixes with air and burns. But this malfunction may not appear until the car has driven about 180-200 thousand kilometers. Of course, this figure depends not only on the manufacturer, but also on the operating conditions of the vehicle. The instructions for each device in the car describe in detail what conditions the manufacturer expected during manufacture.

If the driver, without reading the instructions, began to use the car or part for other purposes, then it will become unusable ahead of schedule, and Common Rail injectors also apply to this rule. Many drivers, after a malfunction has been found in the device, turn to a service station, where they try to make repairs free of charge under warranty. Most often, in such situations, the driver is denied due to the fact that the device was not used according to the regulations.

Of course, before becoming unusable, the device hints to the driver that this will happen soon.

The main reason that Common Rail sprayers will soon break down is considered to be difficult to start the engine, increased fuel consumption and unstable operation of the power unit.

• In the early stages, this is not very noticeable, but over time, this malfunction becomes more pronounced.
• The second symptom is black smoke from the exhaust pipe, which means overflow and enrichment of the fuel mixture.
• The next symptom is increased fuel consumption, especially on a cold engine, accompanied by a decrease in power.

Many people know that a car is a large mechanism that includes the operation of several units and mechanisms at once. So, if one of them will not work, or will be, but wrong, then the engine may simply not start. One of these systems is considered to be a fuel system. If you do not take care of it in time, do not make repairs, then the car can break down at any time, even on the road. Therefore, it is very important to carry out timely technical inspection and repair of the main devices of the fuel system.

__________________
Were: MV E320 (210); Kyron, Rexton I, II XVT; 3.2. MB S320 (220); Prado 120; Hummer H2. There is MB W140 300 SE 1994 (sedan). MB W140 S320 Long (1999) best car. Ahead of the TLC 200; G55 AMG; Porche Panamera; Bentley Continental))

__________________
Were: MV E320 (210); Kyron, Rexton I, II XVT; 3.2. MB S320 (220); Prado 120; Hummer H2. There is MB W140 300 SE 1994 (sedan). MB W140 S320 Long (1999) best car. Ahead of the TLC 200; G55 AMG; Porche Panamera; Bentley Continental))

It will never be sufficient if at least one nozzle in the return flow drains in full - this pump does not have such high performance, and before the control of the nozzles in the ramp and all the pipes, a minimum pressure must be created - I have already written a thousand times how to start in order to get there in this case.

p / s from a flexible starter you can still try if one force is pouring, and if all the kalpanochki are “skipped”, this may mean that either the pump has driven chips, or some water has been grabbed - the result or replacement is the repair of the force (from 4-x-16- 34t.r., Up to 120t. - in any case, not cheaper than the previous version —-, which is a natural result (I repeat) “cheap” diesel cars. ...

The injectors of a diesel engine, as well as an injection engine, are periodically contaminated. Therefore, many owners of cars with a diesel engine are wondering how to check injectors on a diesel engine? As a rule, in the event of their clogging, fuel is not supplied to the cylinders in a timely manner, and there is an increased fuel consumption, as well as overheating and destruction of the piston. In addition, the valves can burn out and the particulate filter can fail.

Diesel injectors

In modern diesel engines, one of two well-known fuel systems can be used universally. Common rail (with a common ramp) and unit injectors (where a separate injector is supplied to each cylinder).

Both of them are capable of providing high environmental friendliness and engine efficiency. Since these diesel systems function and are arranged in a similar way, but Common Reil is more progressive in terms of efficiency and noise of work, although it loses in power, it has become increasingly used on passenger cars, then we will talk about it further. And we will tell you about the operation, malfunctions and testing of the pump injectors separately, because this is an equally interesting topic, especially for owners of VAG group cars, since software diagnostics are not difficult to perform there.

The simplest method for calculating a clogged nozzle of such a system can be carried out according to the following algorithm:

• at idle speed, bring the engine speed to the level when problems in engine operation are heard most clearly;
• each of the nozzles is turned off by loosening the union nut at the attachment point of the high pressure line;
• when you turn off the normal working injector, the engine operation changes, if the injector is problematic, the engine will continue to work in the same mode and further.

In addition, you can check the injectors with your own hands on a diesel engine by probing the fuel line for jolts. They will be the result of the high pressure fuel pump trying to pump fuel under pressure, however, due to the clogged nozzle, it becomes difficult to pass it. A problem fitting can also be identified by an overestimated operating temperature.

Checking the volume of discharge to the return

As the diesel injectors wear out over time, the problem arises that the fuel from them flows back into the system, due to which the pump cannot build up the required working pressure. This can result in problems with starting and operating the diesel engine.

Before checking, you will need to buy a 20 ml medical syringe and a dropper system (you need a 45 cm tubing to connect the syringe). To find a nozzle that throws more fuel into the return line than it should, you must use the following algorithm of actions:

• remove the plunger from the syringe;
• on a running engine, using the system, connect the syringe to the “return” of the injector (insert the tube into the neck of the syringe);
• hold the syringe for two minutes so that fuel is collected into it (provided that it will be collected);
• repeat the procedure one by one for all injectors or build a system for all at once.

Based on the information on the amount of fuel in the syringe, the following conclusions can be drawn:

Checking the overflow to the return

• if the syringe is empty, then the nozzle is fully functional;
• the amount of fuel in a syringe with a volume of 2 to 4 ml is also within the normal range;
• if the volume of fuel in the syringe exceeds 10.15 ml, this means that the nozzle is partially or completely out of order, and it must be replaced / repaired (if it pours 20 ml, then it is useless to repair, since this indicates wear of the nozzle valve seat ), since it does not hold the fuel pressure.

However, such a simple check without a hydrostand and test plan does not give the complete picture. Indeed, in fact, when the engine is running, the amount of discharged fuel depends on many factors, it can be clogged and needs to be cleaned, or it hangs and needs to be repaired or replaced. Therefore, this method of checking diesel injectors at home allows only to judge only about their throughput. Ideally, the amount of fuel they pass through should be the same and be in the range of up to 4 ml in 2 minutes.

In order to keep the injectors in operation for as long as possible, fill up with high-quality diesel fuel. After all, it directly depends on the operation of the entire system. In addition, install original fuel filters and do not forget to change them in time.

A more serious check of diesel injectors is carried out using a device called maximeter... This name refers to the special reference nozzle with spring and scale. With their help, the pressure of the start of injection of diesel fuel is set.

Another verification method is to use control model working nozzlewith which the devices operated in the engine are compared. All diagnostics are performed with the engine running. The algorithm of actions is as follows:

• dismantle the injector and the fuel line from the engine;
• a tee is connected to the free union of the high pressure fuel pump;
• loosen the union nuts on other high pressure fuel pump fittings (this will allow the fuel to flow to only one injector);
• the control and test nozzles are connected to the tee;
• activates the decompression mechanism;
• rotate the crankshaft.

Ideally, the reference and test injectors should show the same results in terms of starting fuel injection at the same time. If there are deviations, then it is necessary to adjust the injector.

The control sample method usually takes longer than the maximeter method. However, it is more accurate and reliable. You can also check the operation of the engine and injectors of the diesel engine and high-pressure fuel pump on a special control stand. However, they are available only at specialized service stations.

You can clean the injectors of a diesel engine yourself. Work must be done clean and well lit. For this, the nozzles are removed and washed either in kerosene or in diesel fuel without impurities. Before reassembling, blow out the nozzle with compressed air.

It is also important to check the quality of the fuel atomization, that is, the shape of the “flame” of the nozzle. There are special techniques for this. First of all, you need a test bench. There they connect a nozzle, supply fuel to it and look at the shape and force of the jet. Often a blank sheet of paper is used for testing, which is placed underneath it. Traces of fuel ingress, torch shape and other parameters will be clearly visible on the sheet. In accordance with this information, it will be possible to make the necessary adjustments in the future. A thin steel wire is sometimes used to clean the nozzle. Its diameter should be at least 0.1 mm less than the diameter of the nozzle itself.

The most common cause of a malfunction is a violation of the tightness of the seating of the needle in the nozzle guide sleeve. If its value is reduced, then a large amount of fuel flows through the new gap. In particular, for a new injector, a leak of not more than 4% of the working fuel that enters the cylinder is allowed. In general, the amount of fuel from the injectors should be the same. You can detect a fuel leak at the injector as follows:

• find information about what pressure should be when opening the needle in the nozzle (it will be different for each engine);
• remove the nozzle and install it on the test bench;
• create a knowingly high pressure at the nozzle;
• using a stopwatch, measure the time after which the pressure will drop by 50 kgf / cm2 (50 atmospheres) from the recommended one.

Checking the injector at the stand

This time is also spelled out in the technical documentation for the engine. Typically, for new injectors, it is 15 seconds or more. If the nozzle is worn, this time can be reduced to 5 seconds. If the time is less than 5 seconds, then the injector is already inoperative. You can read additional information on how to repair diesel injectors (replace nozzles) in the additional material.

If the valve seat of the injector is worn out (it does not hold the required pressure and excessive draining occurs), the repair is useless, it will cost more than half the cost of a new one (which is about 10 thousand rubles).

Occasionally, the diesel injector will ooze lightly or profusely. And if in the second case only repair and complete replacement of the nozzle is needed, then in the first case you can do it yourself. In particular, it is necessary to grind the needle to the saddle. After all, the main reason for leakage is a violation of the seal at the end of the needle (another name is the sealing cone).

To remove the leakage of a diesel injector, a fine grinding paste GOI is often used, which is diluted with kerosene. During lapping, care must be taken that no paste gets into the gap between the needle and the bushing. At the end of the work, all elements are washed in kerosene or diesel fuel without impurities. After that, you need to blow them with compressed air from the compressor. Recheck for leaks after assembly.

Partially defective injectors are not critical, but very unpleasant breakdown... After all, their improper operation leads to a significant load on other components of the power unit. In general, the machine can be operated with clogged or unadjusted injectors, but it is advisable to carry out repairs as soon as possible. This will keep the car's engine in good working order, which will save you even more money costs.So when the first symptoms of unstable operation of injectors on your diesel car appear, we recommend at least an elementary way to check the performance of the injector, which, as you can see, everyone can do at home.

Club forum for owners of minibuses HYUNDAI STAREX, H-1, GRAND STAREX

Message: №1 Serj »10 Oct 2013, 21:25

Taken from a friendly forum. Thanks to Yuri.

Everything is very simple. The high-pressure fuel pump supplies fuel to the fuel rail, which acts as a receiver, where the fuel is at a constant high pressure of more than 1,000 bar. The injectors are opened not as in a “conventional diesel” - hydromechanically (from pressure increase), but electronically - by a signal from the ECU. The uniqueness of this system lies in the fact that it allows a diesel engine manufacturer to SIGNIFICANTLY improve efficiency, power, reduce operating noise, and increase acceleration dynamics. All of the above applies not only to diesel engines, but also to gasoline cars.

These are the well-known D4D and GDI. Each of these systems is good in its own way. But, like many others, they have their drawbacks. That's exactly about these shortcomings and problems, but only in the "diesel version", we will try to tell you. As a full-fledged "repair" unit, our workshop has existed recently, each person from our "team" acquired their experience independently.

And it is worth telling about the experience of the first repair of the fuel system of the 2001 KIA Sorento car. release with 4DCB Common Rail engine. This was the first "Common Rail" that came to our workshop.

Before us, the car had visited many other auto repair shops, and the diagnosis given to this car was simply disastrous. And the “medicine” was spelled out short and incomprehensible: “trash heap.” I don’t know. I do not understand. And I can't understand. So, it's simple: take and send "out of sight and away"? And the problem turned out to be so simple! But at the same time, it is not entirely clear at the first time. So we need to talk about this in detail. The simplicity lay in the malfunction itself. And the difficulty lies in understanding and solving this problem. Here's what actually happened:
- The car worked well at idle.
- She behaved perfectly in all modes.
- Dynamically accelerated.
- The fuel consumption was quite satisfactory for the owner.

But there was a problem.
If the car was turned off, it was almost impossible to start it. Besides "dichlorvos". That is: it was necessary to remove the inlet pipe or open the air filter cover and spray a combustible mixture into the pipe. And only after that it was possible to start the engine. This procedure took place regardless of whether the engine was cold or hot. It was in such a terrible state that the "patient" arrived to us. “Finally, our time has come!”, - I thought, and with a “smart” look took an automobile scanner in my hands. In the hope that he will tell me “where and what the patient hurts”.

But it was not there!
True, the scanner gave us a malfunction code of one fuel rail pressure sensor. And when we "erased" it, we immediately tried to start the engine. The situation has not changed. Didn't start. Upon repeated scanning, no error codes were found - most likely, it was an “old” fault code that remained from the previous workshop. Consequently, our hopes for a successful solution to the problem, with a simple “wave of a magic wand” in the form of a car scanner, melted away, and sleepless nights looming ahead in search of technical documentation. Which we didn't have at that time. And what happened was incomplete, fragmentary and not entirely clear at that time.

In short, no one knew what to do and where to start.

But I really wanted to "NOT hit my face in the mud." After all, the owner of the car looked at us as "the last hope." And I really wanted to believe it. And with all his appearance he made it clear to us. And we understood each other. After slapping our hands, we started our favorite pastime: "Looking for a needle in a haystack." If you remember, I said that this was our first engine with such a control system.Although we read a lot about them, as practice has shown, this is not all. And the “haystack” was not that big. The first thing that came to mind was to scan the control system again using the current data in the following modes:
- when the engine is running
- when we try to start it Knowing that the pressure in the fuel line on the 4DCB engine should be:
- at startup not less than 25MPa,
- at idle speed 30MPa,
- at maximum 135MPa,
- we focused on the study of launch characteristics.

And, as time has shown, we were not mistaken. When the engine was running, the fuel rail pressure was 28MPa from the desired 30MPa. But at startup, the picture is different: 17MPa from the desired 25MPa. This alarmed us. After all, “the system is not stupid” and the fuel rail pressure sensor is not just an element that we have seen before. In its case there is a membrane with a semiconductor primary converter, as well as an electronic circuit for signal processing with a measurement accuracy of up to 2% (at a pressure of 150 MPa). It is simply impossible to replace this sensor. Checking is also problematic. But we also could not consider it faulty. Too large pressure loss at start-up - up to 8MPa.

And this is what was found during a complete check of the entire system for leaks at the moment of start-up (all measurements were carried out in the same way for each nozzle. Cranking time with a starter 5 sec. And a volumetric flask, with a standard 20mil / liter, cc. 1st nozzle: 5 sec. 8 -10 mil, lit. 2nd nozzle: 5sec. 0mil, lit. 3rd and 4th nozzles are the same as for the 2nd nozzle. “Bad” or “good” we did not know then. It is impossible to check these nozzles for “spray quality” on a simple stand (remember the pressure at which they work). But it is possible to check for the percentage of leakage. This is actually the whole further repair of the faulty nozzle.

All of the above was just a preface. And the most important thing was to correct the malfunction itself. When the owner found out the problem, he was very happy and ran for a new nozzle. But he returned very quickly and without her. He said that they requested $ 1200 for delivery. And the order will be completed within a month, maybe more. The fact is that we live in the city of Yakutsk and, as you yourself understand, in many of the benefits of civilization are “somewhat” limited. Therefore, I had to "do" it. Unfortunately, not all material was captured in the photo. This idea did not come immediately and therefore we will post only the material that we have left. And we will devote further narration only to the problem of injector repair. Since all the other nuances will take even longer, and I would not like to go into their details now.

Rice. one.
1. Cross-shaped guide. 2. Needle. 3. Sprayer. 4. Spring locking needle. 5. Locking multiplier. 6. Multiplier bushing. 7. Hydraulic control chamber jet. 8. Ball control valve. 9. Stock. 10. Anchor. 11. Electromagnet. 12. Valve spring. 13. Carbon coating.
Above the figure below (Figure 2), we present a diagram of the R.BOSCH electro-hydraulic injector, which we encountered on this machine, but in a new version of its design - with an additional spring (1).
This spring serves to cushion the force directed to crushing the ball (5) (fig. 2). And at the same time it is the closing spring of the multiplier channel (6), Fig. 2. What was our main problem.

Rice. 2.
1. Valve closing spring 2. Electromagnet 3. Armature 4. Damping spring 5. Valve 6. Closing multiplier 7. Hydraulic control chamber nozzle 8. Slotted filter 9. Inlet fitting 10 - stem (blue) 11 - ball holder (red) 12 - ball (green)
Let's consider only the problem of the control unit of the electro-hydraulic chamber (Figure 2, close-up). The difference between these nodes shown in Fig. 1 and 2 is that in the first version (Fig. 1) there is no valve closing spring in the upper part of the nozzle.

Therefore, the main functions of locking and damping that occur during operation fall on one unit - the valve spring 12 - Fig. 1A in Figure 2 with the addition of a spring (1), there was a distinction between the locking and damping forces.Although in the first version (Fig. 1) we achieve a greater closing force of the spring. But its performance is good in less "revving" engines. For example, on trucks of the same Common Rail family. And when considering small values ​​of feed and high torque, the second option is more preferable (Fig. 2) due to the fact that the distribution of the locking and damping forces of the control chamber has become more stable from cycle to cycle at the moment of fuel supply (at the ratio of the multiplier diameter to needle 1.2 ... 1.5).

But with different ratios of the diameter of the multiplier to the needle, the process becomes more precise and controllable. But in our case, we would not like to consider the theory of mass and the ratio of the forces of the speed of the system. And let's try to understand the problem of the malfunction itself ... When we disassembled the upper part of the nozzle, and studied it in detail, we realized that we would have to deal not with “millimeters”, but with “hundredths of a millimeter”!
Because the diameter of the ball was 1.35 mm, and the diameter of the choke in the control chamber was 0.23 mm. But the surprises didn't end there. On closer examination of the stock, we saw an end fracture along the axis of the stock. And quite deep.

This is the first thing.
The second is the bottom of the stem.
Place of contact between the ball holder and the wide area of ​​the stem. We saw a "punched" dent.

In the photo: 1 - the rod of the hydraulic control chamber, which was made to fit the ball size, 1.32 mm, and installed on the machine in the final version. The rod 2, number 2, was made in the first version, but it turned out to be shorter than the standard one by 0.09 mm. As a result, it remained unclaimed. Figures 3 and 4 show one of the samples of wood milling cutters on which we found the size of the control chamber locking ball that suits us, (Fig. 1 number 8). The rest of the photographs are not related to the details of the nozzle. These are metal bearing debris.

It is not always necessary to simply change a part without fully understanding its work. Perhaps someone will say that it smacks of adventurism. Let them talk. This is their right. My opinion is: “Don't be discouraged. It becomes a habit! " Well, that's probably all.

Checking the injectors for draining to the return line.
We take four 20 and cubic syringes and go.