Komatsu 6754-11-3011 injector

Product details

The principle of operation: nozzles for Komatsu engines are usually supplied with brands such as Bosch. In the absence of power, the electromagnetic valve spring holds the core of the electromagnetic valve in the closed position. On the upper surface of the plunger and the area of ​​the needle -shaped boss, the same fuel pressure is valid. Thanks to the large area of ​​the effort of the upper surface of the plunger, a large directed force is created, which holds the injector's needle valve closed. When the ECM sends the voltage signal, the electromagnetic valve generates the electromagnetic force directed upward, which moves the iron core up, opens the oil drain channel, reduces the pressure on the upper surface of the plunger, lifts the needle valve and sprays fuel into the cylinder through the nozzle hole; After the ECM turns off the power of the electromagnetic valve, the electromagnetic force disappears, the iron core of the electromagnetic valve returns to the starting position, closing the oil drain channel, and the plunger/needle valve returns to the starting position, completing the fuel injection.

Structural composition: usually includes a solenoid valve, plunger, needle valve, spring, nozzle and other components. The solenoid valve controls the timing and duration of fuel injection, the plunger and needle valve work together to control fuel injection, the spring provides the return force, and the nozzle atomizes the fuel and injects it into the cylinder.

Features of the product: it has the possibility of high -precision fuel injection and can accurately adjust the amount and time of fuel injection in accordance with the operating conditions of the engine, optimizing the combustion process and increasing the engine power, efficiency and emissions. The nozzle of the fuel injector is specially designed and made to achieve a good effect of spraying fuel, complete mixing of fuel and air and increase the efficiency of combustion. The material is excellent and has strong resistance to high temperatures, high pressure and corrosion. It can adapt to severe working conditions inside the engine and provide long -term stable and reliable operation.

Stages of installation

Preparation: Clean the injector and the installation site, prepare the necessary tools, such as wrenches, dynamometric keys, etc., as well as accessories, such as new sealing gaskets.

Remove the protective cap: Remove the protective cap from the injector nozzle, check the condition of the copper sealing ring at the end of the injector nozzle, if it is damaged or aged, replace it. Be careful not to damage the nozzle hole during installation. Only one gasket is allowed to be assembled on each injector, and it cannot be reused.

Lubricate the O-ring: Use engine oil, assembly oil or diesel fuel to lightly lubricate the O-ring on the injector body.

Insert the injector: Insert the injector into the mounting hole of the cylinder head and manually press the injector to the shaft flange; if necessary, first fix the clamping part on the injector and then insert it. Please note that it is not allowed to hit the solenoid valve cover, solenoid valve head, wiring harness connector and other parts with tools.

Set the clamping plate and bolts: making sure that the mounting holes are clean, install the clamping plate and bolts of the clamping plate into the clamping part of the injector and apply the correct tightening moment to the bolts to control the axial sealing pressure of the injector within 7000–9000 N.

Set the high pressure fuel tube: remove the protective cap on the high pressure of the fuel nozzle and gently connect the nuts of the high -pressure fuel tube with a thread on the high pressure of the fuel nozzle. Pay attention to mark the cylinders, which include the fuel nozzle and a high -pressure tube. If it is necessary to adjust the high -pressure oil tube, weaken the fixing nut on the appropriate oil ramp for adjustment and, finally, tighten the fastener from the injector in accordance with the required puffing moment.

Install the return oil tube: remove the protective cap from the injector's return oil pipe, insert the plug of the return oil tube vertically into the hole of the injector's return oil pipe on the top, until you hear the sound of fixation of the return oil tube. After the installation is completed, carefully pull the return oil tube with your hand to check if it is installed in place.

Connect the wire harness connector: remove the protective cap of the injector wires of the wires and slowly insert the wire harness connector into the injector wires cut by manually, until you hear the wire harness recorded in place.

Check: visually check the injector system for leaks and other malfunctions.

Common errors

Poor spraying of fuel: low injection pressure, carbon deposits and deposition on a spray, wear of the end surface of the spring or reduction of elasticity, etc. They lead to the fact that the injector opens early and closes late, which leads to poor fuel spray, which, in turn, leads to reducing the engine power, the appearance black smoke from the exhaust pipe and other problems.

The jamming of the needle valve: water or acidic substances in diesel fuel can cause rust and jamming of the needle valve. When the needle -shaped conical surface of the needle valve is damaged, the combustible gas in the cylinder rushes into the mating surface, forming carbon deposits, which also leads to jamming of the needle valve and injector loss of fuel injection.

Fuel injector leak: A poor seal between the injector and the fuel rail, such as an aging or damaged O-ring, can cause fuel leaks. Minor leaks will increase fuel consumption, while major leaks can cause engine failure or even render the engine inoperable.

Injector clogging: Impurities, water, resin and other substances from the fuel settle inside the injector, causing narrowing or even clogging of the injector passage, which leads to problems such as hard starting, slow acceleration and rough idle.

After sales service

Warranty Service: Komatsu generally provides a certain warranty period for its injection products. During the warranty period, if the product fails due to quality problems, users can enjoy free repair or replacement services.

Service Network: Komatsu has an extensive service network around the world with numerous professional service stations and technicians who can provide users with timely maintenance support.

Technical support: Users can get professional technical advice and solutions through Komatsu customer service hotline, online consultation platform and other channels, and learn about the use, installation, maintenance and other aspects of injectors.

Spare parts supply: Komatsu guarantees timely supply of injectors and related parts to reduce equipment downtime and ensure uninterrupted maintenance.

Regular repeated visits: after -sales service employees will regularly visit users to understand the features of the use of injectors and the degree of user satisfaction, collect opinions and offers, as well as constantly improve the quality of products and maintenance.

The common injector malfunctions cover various areas that can significantly affect the performance and operation of the engine. Here are some common injector malfunctions:

Uneven fuel injection: wear or clogging of precision parts inside the injector can lead to uneven fuel injection. For example, if the injector's spray hole is worn out or the needle valve is not hermetically closed, the fuel injection into each cylinder will be uneven, which will lead to unstable engine operation and trembling. This will also affect the output capacity, which will lead to a decrease in power.

Excessive injection pressure: insufficient elasticity of the injector pressure regulation spring, malfunction of the pressure regulation mechanism or blockage of the internal oil circuit can lead to non -standard injection pressure. If the injection pressure is too low, the fuel cannot be completely sprayed and the combustion does not occur completely, which leads to a decrease in the engine power, an increase in fuel consumption and excessive emission of exhaust gases, and black smoke may also appear. If the injection pressure is too high, this can lead to premature and excessive fuel injection, causing a knock of engine and damage to its components.

Feeling fuel nozzles on the snuffle: Frequishers are easily formed on the surface of the nozzle of the fuel nozzle due to the poor quality of fuel, incomplete combustion of fuel in the engine and for other reasons. Carbon deposits clog the dispersal holes, which affects the shape of the torch and the efficiency of the spraying of the fuel, as a result of which the fuel does not spray evenly in the cylinder, which reduces the engine performance, complicates the release and makes an unstable idle stroke.

The jerking of the needle valve: The needle valve plays a key role in the control of fuel injection in the injector. If the needle valve is damaged by impurities, colloids or due to wear, corrosion, etc., it can get stuck in an open or closed position. If the needle valve is stuck in the open position, this will lead to a constant fuel leak, an increase in fuel consumption by the engine and can even lead to engine malfunction; If the needle valve is stuck in a closed position, the injector will not be able to spray fuel, and the engine will not start.

Electromagnetic valve malfunction: In electronic fuel nozzles, the electromagnetic valve is responsible for controlling the time and amount of fuel injection. If the coil of the electromagnetic valve is closed adversarily, open or worn out, the electromagnetic valve will not work properly. When the electromagnetic valve fails, the injector may not be able to inject fuel in accordance with the instructions of the engine control unit, which will lead to the abnormal operation of the engine and the occurrence of problems such as poor acceleration and unstable engine operation at idle.

Poor sealing: aging, damage or improper installation of seals at the injector connection points with the fuel supply, the cylinder head, etc. will lead to poor sealing and fuel leakage. Fuel leak not only leads to its waste, but can also cause dangers, such as fire. It will also affect the normal operation of the engine and will lead to a decrease in power.

Switching of fuel from the nozzle: if the nozzle is closed, and the needle valve is loosely closed or the pressure adjustment spring is insufficient, fuel will occur. The leakage of the fuel from the nozzles will lead to the unstable operation of the engine at idle, increase the fuel consumption and affect the concentration of the mixture, which will lead to incomplete combustion and increased emission of exhaust gases.