DIY CRDI nozzle repair

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.

On Goretsky 95, this is Autocity, they have already noted themselves on the forum, call their master Sergey

DELPHI authorized diesel service, and BOSCH.
Diagnostics and repair of CR, unit injectors.
+375 26 389-85-07

Recently, as yesterday I changed the glow plugs to my typewriter well, and noticed that after repairing the injectors for the "Bosch Diesel Service", I installed injectors in the Y-Z-Y-Y sequence, although before the repair (I looked at the nozzle numbers) there was a Z-Y sequence - Y- Y.

This is the question, how important is it? What does it affect? What is the Difference Between Y and Z Nozzles

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Can be removed - these pictures will help to install the injectors.

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author legall SantaFe-Autoclub
So I suffered and paid with money too. Maybe someone will come in handy.

CRDI injectors
File sent struzhkin SantaFe-Autoclub

Diagnostics of electronic components of the Common Rail injection system, Electronic Equipment Repair Magazine

The level of information value is amazing, I can say that this is the first real source for diagnosing a Common Rail engine that I came across.As soon as it was not published before!

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author legall SantaFe-Autoclub
So I suffered and paid with money too. Maybe someone will come in handy.

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from my experience I can add:
the method described in the injector diagnostics article works and is the simplest, fastest and most free.
indeed, by the amount of fuel in the cups, it is possible to determine an incorrectly working injector.

so there is a problem: troit, won't start, smoke, etc. (I personally have Troilus at idle).
there were solutions

1) go to the comon rail repair station.
There, diagnose injectors (2000 rubles for 4 pieces and put the same amount for removing.
We must not forget that the injector sealing rings, as well as the injector mounting bolts - after each removal - need new ones. It is necessary to find out in advance whether there are washers and bolts at the station specifically for the trajectory. The catalogs contain these parts and they can be ordered (I will describe them below).
Immediately clarify the cost of the repair (before diagnostics) and what is included in it. For example, repairing the nozzle itself (separator, setting gaps, etc.) is one thing. And replacing the atomizer is different. Better to do both.
There is one myth that they like to scare at the station and spread it to new nozzles - this is that the sprayer is not sold separately, because in the west everything is changed by nodes, etc.
So - a spray for d4ea nozzles - sold in existential.

As a result, what can we have from such a repair: 4000r for diagnostics and remove to supply + bolts and washers at cosmic prices + repair of the nozzle with replacement of the sprayer (which at the station sells for 4tr instead of 1800) and repair work 4tr = count yourself.

2) the option is a little more complicated, but more interesting)))
we measure the return line with cups. which nozzle pours less or more - we remember. if everything is poured in different ways, then we are preparing to shoot everything.
then we order in existential fastening bolts (60 r per piece) and washers (10 r per piece) and a better spray (BOSH for 1800). remove the injector (as shown in the diagram above) there is one feature - when the injector mounting bolt is unscrewed - REMOVE IT SLOWLY AND CAREFULLY, BECAUSE THERE IS A FORK UNDER THE VALVE COVER, INTO WHICH THE NOZZLE IS INSERTED AND WHICH IS BOLTED. IT SHOULD NOT DROP, OTHERWISE IT IS NECESSARY TO REMOVE THE COVER OR THROUGH A SMALL HOLE ATTEMPT TO PUT IT INTO THE PLACE FOR A LONG TIME. when you removed the nozzle, immediately tighten the bolt with
with a fork in the thread. God forbid it does not fall.

Then we carry the nozzle, spray and washer to the service. For the money it will come out in 3-4 thousand (for work).
we take the repaired nozzle and put it in place. check.

The injection mechanics is the main difference between a diesel engine and a gasoline engine. In a diesel internal combustion engine, fuel is supplied to the combustion chamber using a nozzle. The device injects fuel in a metered manner into a chamber with a high temperature and pressure, after which the diesel fuel ignites.The nozzle is subjected to the greatest load: the part is constantly in an aggressive environment and works at high intensity. Any negative factor can disable the part or significantly reduce its resource, after which the diesel engine nozzles will need to be repaired.

To understand the mechanics of the injector, we will describe the injection cycle schematically:

• The injection pump takes fuel from the tank;
• then the pump saturates the fuel rail with diesel fuel;
• fuel enters the channels that lead to the nozzle;
• inside the nozzle, fuel flows to the sprayer;
• when the pressure on the atomizer reaches the set threshold, the nozzle opens and diesel fuel enters the combustion chamber.

Let us describe the design of the part using the example of a primitive mechanical nozzle with 1 spring. In the lateral part there is a channel that provides a continuous supply of diesel fuel. Inside the nozzle chamber there is a movable barrier with a spring and a needle, which drops when the pressure rises. The needle rises, clearing the path of fuel to the sprayer.

Additionally, more advanced types of nozzles can be noted:

1. Piezoelectric: The spring pusher is lowered by a piezoelectric element. This technology provides a high intensity of opening of the atomizer: fuel economy is achieved, while the internal combustion engine operates more smoothly.
2. Electro-hydraulic: The design includes an inlet and outlet choke and an electromechanical valve. The operating mode of the components is controlled by the engine control unit.
3. Unit injectors: used in engines that do not have a high-pressure fuel pump. The fuel is supplied directly to the nozzle. These spraying devices have their own plunger pair inside, which generates the pressure required for injection.

Due to excessive loads, the injector may fail due to a violation of the operating mode of the motor. Manufacturers declare the resource of parts to be up to 200,000 km, but due to negative operating factors, wear of parts appears much earlier.

Repair of diesel injectors may be required for the following reasons:

1. Low quality diesel fuel: the scourge of all "diesel operators". Due to impurities in the fuel, the sprayer becomes clogged; the dosage and the fuel supply mode are violated.
2. Poor assembly quality of the injection component or factory defect: the injector does not withstand the operating conditions, the part as a whole or individual components fail.
3. Mechanical damage caused by incorrect operation of adjacent ICE systems.

Usually, breakdowns are of the following nature: the spray angle and the amount of supplied fuel change, the integrity of the body is violated, and the needle travel deteriorates.

Let's briefly describe the "symptomatic series":

• jerks and jerks are felt when moving;
• The internal combustion engine is unstable at idle, stalls;
• when the engine is running, an excessive amount of exhaust is emitted;
• tangible loss of traction;
• failure of individual cylinders;
• gray or black smoke from the exhaust pipe.

It is preferable to entrust the routine maintenance or overhaul of diesel engine injectors to qualified specialists - they will be able to restore and adjust the part on high-precision automated stands. However, a certain set of repair procedures can be carried out in artisanal conditions without the use of complex equipment.

To carry out self-service of diesel engine sprayers, the car owner will need:

• a set of open-end or spanner wrenches;
• screwdrivers for straight and Phillips head;
• clean dry rags;
• maximeter;
• flushing fluid for internal combustion engines.

It is recommended to carry out work in a dry and lighted, dust-free garage.

Diagnostics of diesel injectors and their maintenance involves removing the nozzles from the internal combustion engine.Before starting work, it is recommended to thoroughly wash the engine and engine compartment to avoid the ingress of debris and foreign particles. With particular fondness, you need to rinse the cylinder head. High pressure tubing should be marked with markings to avoid confusion during reassembly.

Before removing it is necessary to close the nozzle fittings (use plastic caps) to avoid contamination. It is not recommended to use ordinary open-end wrenches to dismantle the nozzles - an inexperienced repairman can strip the threads from the nozzles. If the required qualifications are not available, use spanners and a long-handled head tool.

After removing the nozzles from the holes, dry them and remove external dirt with a rag. O-rings are placed in the holes of the nozzles. When repairing injection parts, they are replaced with new ones without fail. Do not allow dirt from the rings to get into the injection system during removal.

There are several methods to check if the sprayer is working properly. The easiest way is to check the injector while the engine is running:

1. Start the "engine" at idle speed.
2. Begin to unscrew the nozzles one by one in turn.
3. If, after removal, the operation of the motor has deteriorated, then the remote nozzle is operational and must be returned to its place.
4. By the method of elimination, you will find an injector, the dismantling of which will not change the operating mode of the internal combustion engine. This will be the broken device.

You can use a multimeter for diagnostics. In advance, it is necessary to throw off the battery terminals and disconnect the wiring of the injectors, and then "check" every detail with the device. On high resistance injectors, the device values ​​will be in the range of 11 - 17 ohms; at low impedance, the multimeter will show up to 5 ohms.

The defective injector must be inspected. First, we look for leaks in the body of the part. If there are none, proceed to disassembling the part. We fasten the part in a vise and knock out the sprayer with a gentle tap. Next, you need a thorough cleaning: we soak the parts of the nozzle in diesel fuel or solvent to remove carbon deposits. Remove fumes and deposits with a fine steel grater. After completing the cleaning, you need to check the nozzle at the maximum meter. If the optimal injection parameters have been achieved, the device is ready to be installed in the engine.

In other cases, it is necessary to completely replace the atomizer on the defective nozzle. When installing a new part, carefully remove all factory grease, otherwise the device will not work.

Before disassembling the device, mark all parts with a marker to avoid confusion. Be especially careful when marking high pressure hoses. The nozzle is screwed in by hand as far as possible. Further tightening is done with a dynamometer wrench. For tightening values, refer to the motor manual. After installing the injector, evacuate air from the fuel system. On modern cars, it is enough to turn the starter several times for this; or use a manual priming pump (if equipped).

Let's list the main features:

• the resource declared by the manufacturer has been developed;
• there are breakdowns on the case, other leaks;
• burnt out spray nut: if the problem is not eliminated early, the spray itself will become unusable.

Please note that on some engines, after installing a new injector, it is necessary to "tie" it to the engine: make changes to the settings of the control unit.

Self-repair of injectors is a rather forced measure. Such a service in artisanal conditions can bring success only in the case of the highest qualifications of the master. The main problem of garage repairs is the lack of high-precision bench equipment for diagnostics. The repairman cannot objectively assess the effectiveness of the service measures.

If there is an opportunity to contact a service station, do not neglect it: computer equipment and cleaning stands will extend the life of the injectors and save them from potential expensive repairs. The same ultrasonic cleaning can save a motorist from engine problems for several seasons. It is not possible to repair modern Common Rail injection systems in a garage: you need a mandatory fine-tuning of the part by computer.

Use a cleaning fuel additive to avoid costly repairs and replacement parts. They prevent the formation of carbon deposits and the settling of deposits. The use of additives should be systematic, not one-off. Remember, additives are about preventing breakdowns, not fixing them.

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

Message uragobelkov »15 Mar 2011, 09:09

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.

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.