New High Quality Diesel Nozzle DLLA152P947 for Injection Nozzle Diesel Engine Parts

Structure and type of fuel injector nozzle
1. Core structure
Injection hole: the channel for fuel to be sprayed out, the hole diameter is usually 0.1-0.3mm, with extremely high precision, which determines the fineness of fuel atomization.
Needle valve assembly: It consists of a needle valve and a needle valve body, which is opened and closed by a solenoid coil or hydraulic control to control the amount and timing of fuel injection.
Pressure chamber: the space below the needle valve, where the fuel forms high pressure and is sprayed out through the injection hole.
2. Common types
Type Features Application scenarios
Hole-type nozzle The number of injection holes is 1-8, with a small hole diameter and good atomization effect, which is suitable for direct injection engines (such as diesel engines). Diesel engine, direct injection gasoline engine
Axis needle nozzle The front end of the needle valve has an axis needle extending into the injection hole to form a ring-shaped spray hole, and the spray is conical with strong anti-clogging ability. Manifold injection gasoline engine
Flake valve nozzle The thin-film valve is used to replace the needle valve, which has a fast response speed and uniform spray atomization. It is mostly used in modern electronic control systems. High-end gasoline engine

Working principle of fuel injector nozzle
Control logic of electronic fuel injection system
The engine ECU (electronic control unit) sends electric pulses to the injector solenoid coil according to signals such as speed, load, and temperature:
When powered on: the solenoid coil generates a magnetic field, sucks up the needle valve, and the fuel is sprayed out from the injection hole under high pressure.
When powered off: the needle valve is closed under the action of the spring force and the fuel injection stops.
Fuel atomization mechanism
When high-pressure fuel passes through the narrow injection hole, the high-speed fluid injection generates shear force, breaking it into fine oil droplets (usually 5-50μm in diameter), which mix with air to form a combustible mixture.

Common faults and causes of fuel injector nozzles
1. Blockage
Reason: Fuel impurities (such as colloid, metal debris), carbon deposits or improper use of fuel additives block the injection hole.
Symptoms: engine idling jitter, poor acceleration, increased fuel consumption, and excessive emissions.
2. Leakage
Reason: Needle valve wear, aging of sealing surface or excessive fuel pressure leads to fuel leakage.
Symptoms: Difficulty in starting (fuel dilutes the mixture), black smoke from the exhaust pipe, and obvious fuel smell.
3. Poor atomization
Reason: The injection hole is worn and enlarged, the needle valve is stuck, or the injection pressure is insufficient, resulting in coarse oil droplets.
Symptoms: Incomplete combustion, power reduction, and serious carbon deposits on the spark plug.
4. Stuck or not working
Reason: Solenoid coil failure, needle valve is stuck by colloid, or mechanical parts are worn.
Symptoms: A cylinder does not work (missing cylinder), and the engine fault light is on.

Maintenance and care of the injector nozzle
1. Daily use recommendations
Use high-quality fuel: Low-quality fuel has high sulfur content and many impurities, which can easily cause carbon deposits and blockages. It is recommended to choose fuel products from regular gas stations.
Regularly add fuel cleaner: Use the original certified injector cleaner every 5000-10000 kilometers to dissolve colloid and carbon deposits.
Avoid long-term idling: Fuel atomization is poor at idling, and carbon deposits are easily formed on the nozzle surface. It is recommended to clean carbon deposits by driving at high speed regularly (such as on the highway).
2. Professional maintenance steps
Disassembly and cleaning:
Remove the injector assembly and use an ultrasonic cleaner (special cleaning agent) to remove internal carbon deposits and impurities.
Check whether the injection hole is unobstructed and the needle valve is tight (it can be tested by pressure, and the leakage volume is ≤1 drop per minute under standard pressure).
Pressure test: Use an injector tester to simulate the fuel pressure under engine working conditions (such as 3-5bar for gasoline engines and more than 100bar for diesel engines) to observe whether the injection atomization state is uniform and without deflection.
Replacement cycle: It is usually recommended to replace the injector assembly (or nozzle assembly) every 80,000-100,000 kilometers. If the fuel quality is poor, it can be shortened to 50,000-60,000 kilometers.
3. Troubleshooting tools
Diagnostic instrument: Read the ECU fault code to determine whether the injector circuit is abnormal (such as the coil resistance value should be between 2-5Ω).
Oscilloscope: Detect the injection pulse signal waveform to confirm whether the ECU control is normal.

Precautions
Prevent damage during disassembly: The injector nozzle is a precision component. Avoid knocking or scratching the injection hole with tools. Make sure the sealing gasket is intact during installation.
High-pressure fuel safety: Pressure relief is required before maintenance (disconnect the fuel pump fuse and start the engine until it is turned off) to prevent fuel injection from causing safety accidents.
Match ECU parameters: After replacing the new injector, the diagnostic instrument needs to be used to match the injector code to ensure that the injection volume is consistent with the ECU control strategy.

Through regular maintenance and correct use, the life of the injector nozzle can be effectively extended to ensure the power and economy of the engine. If abnormal symptoms (such as shaking and black smoke) are found, it is recommended to go to a professional maintenance agency for inspection in time to avoid the expansion of the fault.