Diesel fuel injectors: diagnostics and repair
A large number of motorists are faced withbreakages and poor-quality functioning of parts of the power system of diesel power plants. This leads to loss of power, traction characteristics, work with interruptions. The cause of all this can be faulty diesel fuel injectors or their constituent parts.
The process of passing the injection
The power supply of the engine originates from the tank, from where the fuel is taken by the high pressure pump. After that, it moves through the piping system separately into each nozzle and the combustion chambers of the cylinders.
When the required pressure is reached, the plungerThe needle overcomes the spring force and rises, resulting in an injection. It is important that the periodicity of the work is maintained - the plunger must open and close in time. In the case of non-closing, the stability of the motor will be impossible due to the absence of spraying.
The ignition is due to the compression temperature- fuel should be supplied to the cylinder in the form of very small hygroscopic particles. The needle part is not provided with a seal, therefore, through some backlashes, the mixture can enter the chamber of the spring mechanism with the pusher.
For the removal of fuel, a return channel is provided,so as not to lock the plunger. There are nuts on the part that are used to control the injection pressure. The body with the elements of the mechanism is covered by a clamping washer.
Fuel injectors for diesel enginesconsist of the body, the systems of the channels for the transmission of solar oil, the plunger pair (needle, pusher, spring), the fuel supply and discharge chamber, and the saddle of the plunger needle.
Channels are designed to deliver power frompump. The spring must operate at a certain pressure, so that the needle rises in time, the formation of a spray flare and the combustion chamber of the engine cylinders are provided. There are also no sealing gaskets - everything is guaranteed by the precision of manufacturing parts.
What can prevent normal spraying
Formation of a nominal spraying processdepends on the healthy state of the spring, pusher and the presence of various workings of parts that prevent the closure of the system. Under the influence of certain lateral forces, the plunger needle is pressed against the body, preventing full closure.
To protect against such impacts in theThe design includes a pusher that absorbs lateral loads due to curvature of the spring. But it may not perform its functions as a result of the appearance of metal workings. Then you need to replace the pusher or spring mechanism. The need to change the case arises extremely rarely.
How to dismantle diesel fuel injectors
All work is carried out with an inoperative power plant in accordance with safety regulations.
Initially, you should inspect the site for dirt and other excess particles.
After this, you need to do a thoroughcleaning the landing site, wiping it with rags and blowing with compressed air, using a conventional vacuum cleaner with blowing function or a compressor. It will require a set of locating wrench to turn the main and return piping.
Removal and replacement of fuel atomizers is spenthead or a pipe wrench. Use (for twisting this part) carob tools is highly undesirable - there is a risk of deformation of the faces. And this can lead to difficulties during removal or force to change the part of the case.
After unscrewing the nozzle well clean the installation well and all threaded connections. The presence of weeding particles in the thread will adversely affect the density and state of the entire joint.
After cleaning, we put washers and sealingfuel injector rings, made of copper. The planting area must be treated with graphite lubricant. A good connection state will allow the part to be twisted almost to the end, without exerting any effort. The key should be moderately compressed and proceed to the connection of fuel pipelines.
What problems can be caused by spray guns?
A significant part of car enthusiasts often puzzles over the problem of a long engine start.
In this case, there is an effect of initial work, butIn a short period of time unstable functioning is demonstrated. The reason may be the unsatisfactory condition or the incorrect operation of the nebulizers.
There are cases when fed into cylindersuneven amount of solar oil and this increases its consumption. Either the supply turns out to be too small for the rated motor performance. It is possible and the possibility of poor-quality spraying.
If you do not respond in time to such symptoms, you may need to replace the injectors. The serviceability of the power components determines the stable operation of the power plant.
How to replace the spray gun
To solve the problem of settingNew elements will require their acquisition. And if there are elements, you need to dismantle the diesel fuel injectors, following the recommendations for the correct implementation of these operations.
Next, you need to disassemble the parts, replaceSpray the assembly and assemble in the reverse order. It is necessary to exclude the possibility of getting inside the device and the place of mating of dirt and mechanical abrasive particles. This can lead to a rapid failure of new parts or to their unsatisfactory functioning. All elements must be cleaned in containers with clean gasoline.
Please note that during all operations, it is necessary to cover the openings and outlets of fuel pipelines with protective caps.
Setting the engine without checking the performance of the parts will not bring the desired result. A stand for testing the injectors will help determine and adjust the required parameters.
What is the algorithm for setting the injection parameters
When dismantling works are carried out, which entailreplacement of individual components or components, it will be necessary to determine and regulate performance characteristics. At home, it is extremely difficult to do such a complex of operations without proper logistics.
Battery Testing Equipmentmotor is very expensive, so you will need to visit a specialized workshop where there is a stand for testing injectors. The wizards will diagnose and configure the following indicators:
- Rated working pressure of injection;
- adjustment of the spray flare: before the plunger needle operates at specified pressure values, any leaks or jets of fuel are not allowed;
- Check the spray cone, which must have clear boundaries and act in the direction from the hole without any displacement in any direction;
- correctness of the work process.
The adjustment is carried out under conditions similar to those in which the nozzles are mounted on the motor. The check takes place with real workloads.
In the conditions of the SRT, it is possible to perform ultrasonic cleaning of the elements of the power system.
What methods to flush the fuel supply parts
Diesel fuel injectors often suffer partial or total clogging. The problem is the composition of the fuel. It contains a variety of resins. There are ways to remove weeds:
- Do not remove the elements from the engine, by adding to the refueling tank special chemical additives. In the process of work, the contamination will be dissolved and withdrawn from the system.
- Cleaning with ultrasonic devices.The parts are located inside the working chamber of the device, and under the influence of low-frequency waves, various deposits are removed. This procedure does not take a lot of time and money, but it gives a good result.
- Self-cleaning in tanks with clean diesel or gasoline. It can be held at home or in the garage, this will not cause any difficulties.
- Cleansing of resinous deposits with the help of special tools on the stands.
If the defects are not detected in time and the service performed, the injectors may need to be replaced.
What is the cost of parts of the power system
The purchase of devices that supply fuel to the combustion chamber of diesel power plants is not a cheap business.
Depending on the brand, model of the car andthe fuel diesel price is kept within the limits of 10 to 25 thousand rubles, and in some cases even higher. A major overhaul of such parts at service stations will cost from 5 to 9 thousand rubles per set.
Sizes of nozzle power supply systems for motors
By design and principle of operation, the following types of nozzles are distinguished:
- mechanical. These elements are installed on early car models and tractors. They have an understandable structure and simple algorithm for assortment-assembly operations;
- electromechanical. Are present on foreign cars of middle age;
- piezoelectric. The latest development, which is present on the recently produced vehicles brand manufacturers. They differ in complex construction and high cost.
The material for making nozzles has many varieties. The main raw materials are brass, titanium alloys, silicon carbide, as well as special alloys of strong stainless steels.
The service life of such elements depends on the operating modes and harmful influences and can amount to several tens of years of intensive work. It will only be necessary to replace the parts.