Car injectors diesel and petrol

Injection valves serve to supply fuel into the combustion chamber. They are situated in front of the intake pipe. Nowadays in diesel engines a Common-Rail injection system is used. In old car models with diesel engines injection is regulated by hydraulic systems. In the internal-combustion engines are used electromagnetic valves with electric control. Precise injection resolves all the problems if we speak about an optimal use of engine power.

If the injection valves malfunction, this affects combustion. In most cases the problem is that the fuel is irregularly sprayed. In the engine appears knocking and in this case it burns more unsprayed fuel. Other problems arise if the injection jet is installed incorrectly. If the injection valves are directed at the cylinder wall, oil firm burns out and so-called “rusty stains” appear. Moreover, this can cause overheating that leads to piston burning-out.

If there are problems with combustion, the driver hears strange noises in the engine. This is the reason to check the engine and fuel injection valves particularly. In old cars it is possible to check them without any assistance. Modern cars have a lot of electronics and it will be quite difficult do service them. Do you search generator, master brake cylinder, poly-V belt, air conditioner compressor, baggage compartment, tie rod, or any other spare car parts? Use search function in our online shop and you will find necessary parts. We offer you a wide assortment of car parts.

How to detect malfunction of the valve injector

To check the condition of the component, content of carbon monoxide and hydrocarbons in the exhaust gases of each cylinder should be determined. If the injector is in working order, the obtained results should not be different.

To check whether the fuel is injected correctly, connect an oscilloscope to the vehicle body and the injector control device. Malfunctions are detected by the curves on the screen of the device.

Next, check cables connection. To do this, use an ohmmeter. The diagnostics described above is performed with the use of specialized devices; therefore, it should be performed at a service station.

You may notice that the Fuel injector needs diagnostics by the following symptoms:

• the vehicle moves in an uneven manner (with jerks and misfires), when the engine works at high RPM;
• the engine operates incorrectly at idle speed.
• increased fuel consumption;
• the engine has lost power;
• burned hole of the component;
• the engine misfires;
• impaired vehicle performance;
• the catalyzer is faulty;
• the injector nozzle is carbonized;
• the exhaust gases have become more toxic.

The reasons of injector malfunctions

The most frequent malfunction of Fuel injectors is clogging. During operation, the components are exposed to high temperatures, which results in carbonizing the holes of the nozzles with the resins contained in the fuel. This may also be caused by poor tightness of the locking cones. Carbon deposition 5 µm thick results in reducing the flow rate of the nozzle by 25%. When poor quality gasoline containing fine solid particles is used, the fine mesh filter intended for cleaning fuel gets clogged, and the size of the metering orifice and the shape of the injected fuel spray change.

Premature wear of injectors and jamming of the needles in the guides may be caused by poor quality of the components. Needles also get jammed due to insufficient cleaning of the fuel, or due to incorrect installation of the components.

Mechanical damage of the injectors is caused by uncareful repair or by incompetence of the specialist.

Repair of the valve injector

Repair is intended for removing dirt from the component. The component should be cleaned after every 40 thousand kilometers of mileage. Fuel additives help avoiding fouling. To prevent fouling, add them to the fuel after every three thousand kilometers of mileage.

If injector fouling could not have been prevented, clean it using a special solvent. To do so, disconnect the pump and the drainpipe, and connect the fuel line of the injection system with a test bench equipped with a tank filled with solvent. Let the engine run at idle during the first minutes, then gradually increase RPM. The entire procedure should take about one hour. If the component is fouled too much (hard depositions are found), it should be dismantled. Ultrasonic cleaning is very effective. In this case, the component is to be immersed into a washing solution.

Replacing a Fuel injector

If the injectors are cleaned on a regular basis, their service life may reach 200,000 kilometers of mileage. To replace the component, first relieve pressure in the fuel rail. Then remove the connecting pipe going from the air filter, the IAC (idle air control) valve wiring harness, injectors wiring harnesses, and the throttle position sensor wiring harness. Next, disconnect the hose from the fuel pressure regulator, and unscrew the pipes that supply fuel to the fuel rail. After that, unscrew the bolts that hold the rail in place, and remove it. Disconnect brackets of the injector and extract it; replace a faulty component. To install a new component, assemble the unit in the reverse order.