Diesel injectors (ON)

We offer regeneration of injectors and sale of reconditioned injectors of common rail systems from Bosch, Siemens/VDO/Continental, Delphi and Denso. We deal with designs used in passenger vehicles, vans, trucks and commercial vehicles and machines. We are authorised to remanufacture injection system components from Bosch, Delphi and Siemens/VDO/Continental. In the process regeneration of injectors we use state-of-the-art equipment and technology as well as spare parts of the highest quality. The high quality is backed up by a 24-month unlimited mileage warranty.

Genesis and application.

History of diesel injector development spans more than a century of innovation and technological progress. Initially, fuel injection was carried out using high-pressure air, but the first mechanical injectors without air support appeared in the 1920s. During this period, Bosch played a key role, introducing the high-pressure injectorswhich are used in truck and agricultural machinery engines.

In the 1930s, Mercedes-Benz introduced the first mass-produced diesel passenger car, indicating the growing popularity of the technology. World War II accelerated the development of injectors, particularly in a military context. The 1950s and 1960s saw further breakthrough innovations, such as injectors with a back-spring system and the first electronically controlled injection pumps.

In the 1960s and 1970s, dual-spring injectors became standard in many applications, from trucks to agricultural machinery. The introduction of these injectors allowed for better control of the combustion process, which had a direct impact on improving engine performance and reducing fuel consumption.

In the 1990s, Bosch initiated a revolution with its pump-injector system, followed by the Common Rail system, which allows precise control of fuel injection at very high pressure. Today, to maintain the efficiency of these advanced systems, it is crucial to regular cleaning of diesel injectorswhich prevents failures and extends the service life of components.

System with pump injectors, introduced in cars and vans by the Volkswagen Group, was a significant step in the development of diesel injector technology. This system integrated the injection pump directly into the injector, enabling more precise control of fuel injection. Each engine cylinder had a separate pump-injector unit, which provided better control over the injection process and fuel combustion. . offered greater power and efficiency than traditional injection systems, especially in terms of response to changes in engine load and operating conditions. This technology was particularly popular in Volkswagen and other VW Group brands for many years. It has also found applications in truck engines and in machinery and commercial vehicles.

However, as it develops and seeks to further reduce emissions and improve efficiency, system with pump injectors has gradually been replaced by more advanced common rail systems with electromagnetically or piezo-controlled injectors. In this type of system, the fuel compression and injection functions are separated. This enables precise control of fuel injection, resulting in improved engine performance and lower exhaust emissions.

Since the 2000s. injector technology diesel continues to evolve with a focus on reducing emissions, improving fuel dosing accuracy and integration with hybrid systems.

Construction and principle of operation.

Mechanical injectors.

Mechanical fuel injectors were widely used in diesel engines for their simplicity and reliability. 

The injector body is usually made of high-quality steel, which is resistant to high pressure and temperature. The body contains all the other components of the injector and is mounted directly into the engine head. The needle is the key component that controls fuel flow. It is a precision-made piston that moves inside the atomiser. The needle is pressed against the seat by a spring, which prevents fuel leakage when no pressure is applied. The injection nozzle (tip) is located at the end of the injector and has very small diameter holes through which fuel is sprayed into the combustion chamber. The fine atomisation of the fuel ensures better mixing with the air and more efficient combustion. A spring presses the needle against the nozzle seat. The spring force must be adjusted to ensure that the firing pin opens at the specified fuel pressure. By adjusting the spring force, the opening torque of the injector can be set precisely. More advanced injector designs mechanical (so-called dual-spring) injectors have two springs with different strengths. This allows the injector to open gradually and perform pre-injection. The shim is used to adjust the strength of the spring and thus the pressure at which the needle starts to rise. By changing the thickness of the shim, the opening point of the injector can be precisely adjusted. A fuel channel located in the body guides the high-pressure fuel from the injection pump into the interior of the injector. Fuel in the fuel channel causes pressure to build up on the needle. When the pressure exceeds the spring setting, the firing pin rises, opening the injection nozzle. Once the injection phase is complete, the fuel pressure drops, causing the spring to press the needle against the seat, closing the nozzle and stopping the fuel flow.

When injectors are used for many years, it becomes necessary to maintain them and, in many cases, to regeneration of injectorswhich restores full precision to the fuel metering.

Unit injectors.

The pump-injector combines a pump and an injector in its body. The pump section is mechanically driven from the engine, usually by a dedicated cam shaft. A piston moving in the housing compresses the fuel to a high pressure. Each of the unit's pump injectors is equipped with a control solenoid valve, which makes it possible to precisely regulate the amount of fuel supplied to the engine's cylinders. The tip of the pump injector has several small holes to ensure that the fuel is atomised finely enough to promote better mixing with the air and complete combustion.

Electromagnetic and piezo injectors (common rail).

The body is made of durable materials, usually steel, which can withstand high pressure and temperature. The body contains all the components of the injector and is mounted directly in the engine head.

The solenoid is the key control element of the injector. Powered by an electric current, it generates a magnetic field, which allows the control (bypass) valve to open. When the solenoid is activated the valve opens, allowing some of the fuel to return to the overflow and thus the start of fuel injection. The nozzle is located at the end of the injector and contains very small holes through which fuel is fed into the combustion chamber. These holes are precisely made to ensure that the fuel is properly atomised. The return spring is responsible for closing the needle valve when the solenoid stops working. It presses the valve needle against the seat, which closes the injector and ends fuel injection. The fuel channels feed high-pressure fuel from the rail to the inside of the injector. The electrical plug is where the injector connects to the engine control unit (ECU). A current flows through it, which activates the solenoid.

Piezo injectors are devoid of a coil, replaced by a piezo stack. Control of the opening and closing of the injector is achieved using the piezocrystal effect, which involves changing the length of the piezo stack when a voltage is applied to it. Changing the length of the piezo stack activates injector control valve allowing injection to start and stop. The advantage of this design over electromagnetic injectors is the speed of operation, which translates into precise fuel dosage to the cylinder. 

Reconditioning and cleaning process for injectors

Each process injector cleaning and their regeneration are carried out on authorised test benches in accordance with the manufacturers' recommendations.

Unit injectors.

Pump injector tests Bosch, both before and after regeneration, are carried out on the Bosch EPS 815 test bench equipped with the CAMBOX. Only such a set-up allows precise measurement of the pump injector's operating parameters, including the important value known as BIP (Beginning of Injection Period). Reconditioning primarily involves replacing the atomiser, replacing the seals, inspecting and cleaning the remaining components. If necessary, other components such as the piston and spring that are part of the drive system of the pump injector or the control valve components are replaced.

For Delphi's pump injectors, testing and calibration takes place on the Hartridge AVM2-PC test bench. Regeneration of injectors primarily involves replacing the atomiser and control valve, replacing the seals, inspecting and cleaning the remaining components. If necessary, other components such as the spring, electrical connector and others are replaced. If the manufacturer has provided for such a need, regenerated injector pump receives a new correction code, which is generated on the basis of the parameters intended during the calibration test carried out on the test bench.

Electromagnetic and piezo injectors (common rail).

At the customer's request, prior to repair we carry out injector tests. The tests take place on test benches authorised by the individual injection system manufacturers. These include machines manufactured by Bosch, Hartridge and Carbon Zapp. Regeneration of injectors includes all the steps provided for in the instructions prepared by the individual manufacturers. This is usually the replacement of the atomiser, seals and control valve and, if necessary, the solenoid. The remaining components are thoroughly cleaned, verified and reused. Importantly, the equipment generates individual classification or correction codes (IMA/C2i/C3i/C4i) based on the dosage measurements of each injector. Introducing them into the engine controller ensures that the injectors fitted to the vehicle operate correctly.

Reconditioning diesel injectors: causes and types of damage

Symptoms that may indicate faulty injectors:

1. Uneven engine operation.
2. Loud engine operation.
3. Decrease in engine power.
4. Increased fuel consumption.
5. Engine starting problems.
6. Excessive smoke from the exhaust system.
7. Luminous "check engine" light.

If you notice any of the above symptoms, it is essential to quickly cleaning or full diesel injector regenerationto avoid more serious engine failures.

The most common injector failures are:

1. Nozzle damage.
2. Failure of the control valve.
3. Damage to the coil or piezo stack.
4. Internal or external fuel leakage.

Why choose Turbo-Tec services?

Deciding on cleaning of injectors or their comprehensive regeneration w Turbo-Tec, you gain the assurance that your components are in the hands of experienced specialists with many years of experience. We are authorized by the largest manufacturers of injection systems - Bosch, Delphi and Siemens/VDO/Continental - which confirms the highest standards of our services. We carry out all processes on state-of-the-art, certified test benches, and each reconditioned component receives detailed documentation and a 24-month warranty with no mileage limit.
Choosing Turbo-Tecyou are committed to precision, transparency and efficiency - values that make our diesel injector regeneration and cleaning of diesel injectors meet the requirements of even the most demanding customers.

Opt for proven solutions - choose professional cleaning and regeneration of diesel injectors w Turbo-Tec. Contact us today and restore your engine to full power, fuel efficiency and long, trouble-free operation.