Injector malfunctions (injectors) occur as on diesel, and on gasoline engines. In the circuit diagram of the injector engine power supply system, the injector is an element, which is responsible for injecting a sprayed portion of fuel into the combustion chamber under a certain pressure.
We also recommend reading the article about it, what is the engine power system and injector nozzle as a component. In this article you will learn about the device, design features and principles of operation of the engine power supply system.
Accurate dosing, tightness and timely operation of the injector nozzle provide stable and serviceable operation of the engine in all modes of its operation. If the nozzle "pours" (leaks excess fuel at the moment, when its submission is not required), the efficiency of fuel spraying is reduced (the shape of the torch is broken) and other injector malfunctions occur, then the engine starts to smoke gray or black smoke, loses power, consumes a lot of fuel, etc..
Indicating possible problems with the injector
Let's note at once, that the reasons for unstable engine operation can be many, starting from a clogged fuel filter, fuel pump breakdown, failed spark plug or faulty coil to loss of compression, problems with timing, etc.. In addition, one of the main signs of injector failure is difficult engine start, especially "cold", as well as the consumption of gasoline or diesel fuel (depending on the engine type), which increases markedly. It is also necessary to note the unstable operation of the internal combustion engine at idle, I look like the so-called "tripling" of the engine.
When driving may be quite frequent manifestation of one or more symptoms:
- the presence of jerks, very slow reactions when you press the gas pedal;
- obvious failures and loss of dynamics in attempts to accelerate sharply;
- the car may jerk on the go, when releasing gas, as well as after changing the load mode on the motor;
Must be added, that such a fault must be rectified immediately, as problems with the injector negatively affect not only the life of the engine and transmission, but also on general traffic safety. In a car with faulty injectors, the driver may experience severe difficulty overtaking, on steep climbs, etc..
Self-check of injectors
Let's start with that, that car injectors are divided into several types, of which two species are widely used at different times: mechanical nozzles and electromagnetic (electromechanical) injectors.
Solenoid injectors are based on a special valve, which opens and closes the fuel injector under the influence of the pulse of the ECU engine. Mechanical injectors open as a result of increasing fuel pressure in the injectors. Let's add, that electromagnetic devices are most often installed on modern cars.
There are several ways to test the injectors with your own hands without removing them from the machine. The easiest and most affordable way, which allows you to quickly check the injector nozzles without removing them from the machine, there is a noise analysis, issued by the engine during operation.
It is possible to define a faulty nozzle on hearing on a sound of work of the internal combustion engine in that case, if from the block of cylinders the muffled high-frequency sound is reached. This indicates that the injector needs to be cleaned or the injectors malfunctioning.
How to check the power supply to the nozzles
The specified check is carried out in that case, if the injectors themselves are working, but any of the injectors does not work when the ignition is turned on.
- for diagnostics the block is disconnected from an injector, then you need to connect two wires to the battery;
- the other ends of the wires are attached to the contacts of the nozzle;
- then you need to turn on the ignition and record the presence or absence of fuel leakage;
- if the fuel is leaking, then this figure indicates problems in the electrical circuit;
Another diagnostic technique is to check the injector with a multimeter. This method allows you to measure the resistance on the injectors without removing them from the engine.
- You need to find out before you start, what impedance (resistance) have nozzles, mounted on a specific car. The point is, common injector nozzles as with high, and with low resistance.
- The next step will be to turn off the ignition, as well as resetting the negative terminal from the battery.
- Next, you will need to disconnect the electrical connector on the nozzles. To do this, use a screwdriver with a thin end, with which you need to snap off a special clamp, located on the pad.
- After disconnecting the connector, switch the multimeter to the desired operating mode to measure resistance (ohmmeter), connect the contacts of the multimeter to the corresponding contacts of the nozzle for impedance measurement.
- The resistance between the extreme and central contact of the high-resistance nozzle should be within 11-12 to 15-17 Ohm. If the car uses low-resistance injectors, then the figure should be from 2 to 5 Ohm.
If obvious deviations from admissible norms are noticed, then the injector must be removed from the engine for detailed diagnosis. It is also possible to replace the nozzle with a consciously serviceable one, then the operation of the engine is evaluated.
Comprehensive diagnostics of nozzles on the ramp
For such check it is necessary to remove a fuel rail from the engine together with the nozzles fixed on it.. Then you need to connect all electrical contacts to the ramp and nozzles in that case, if these were turned off before removal. It is also necessary to replace the negative terminal of the battery.
- The ramp must be placed in the bonnet space as follows, to be able to put under each of the nozzles measuring container with a scale.
- It is necessary to connect to a ramp of a tube of supply of fuel and in addition to check up reliability of their fastening.
- The next step is ??ignition on, then you need to turn the engine a little starter. It is better to carry out this operation with an assistant.
- While the assistant turns the engine, check the efficiency of all injectors. Fuel supply must be the same on all injectors.
- The final step will be to turn off the ignition and check the fuel level in the tanks. The specified level must be equivalent in each tank.
More or less fuel in the measuring tanks will indicate a malfunction of the injector or the need to clean one or more injectors. If the injector shows underfilling, then the item needs to be cleaned or replaced. Leaking fuel after turning off the ignition will indicate this, that the nozzle "pours" and has lost tightness.
In addition to self-inspection, you can use the service of diagnostic of the injector in the car service. This operation is performed on a special test bench. Checking the injectors on the stand allows you to accurately determine not only the efficiency of fuel supply, but also the shape of the torch when spraying fuel.
How to clean the injectors yourself without removing them from the engine
In the process of diagnosis, a frequent cause of unstable engine operation is that, that the injector nozzles are clogged. There are several ways to clean the injectors, among which mechanical can be used, ultrasonic or cleaning with special chemicals.
We recommend that you read the article about it, what are the methods of diagnosis and cleaning of injector nozzles. In this article you will learn about mechanical, of chemical and ultrasonic cleaning of an injector on an example of cleaning of nozzles of the diesel engine.
In some cases, pouring into the fuel tank of a special additive-cleaner injector is enough for that, to normalize the operation of the entire system. It is also recommended to turn the engine to high speeds at certain intervals and accelerate the car to 110-130 km / year. on equal sections of the road. You need to drive in this mode 10-20 kilometers. Prolonged operation of the nozzles under load allows the implementation of the so-called self-cleaning.
Finally, let's add, that the above cleaning methods can remove only minor contaminants. A severely clogged injector must be cleaned mechanically, compositions under pressure or ultrasound. As for rinsing the nozzles, experts recommend rinsing the injector every 30-40 thousand. Mileage.
Injector cleaning should be done for prevention, and not after the appearance of signs of malfunction. If the car is operated in the city mode on fuel of doubtful quality, then the interval of preventive measures should be reduced in relation to individual operating conditions.