On a VAZ-2107 car, fuel injector fuel consumption depends on many parameters. Of course, the state of the engine is of great importance - the amount of compression, the level of wear of the pistons, rings, valves and their seats and other components. But not only does this affect gas mileage. The fact is that the injection system is completely computerized. Of course, it is not controlled by an ultra-modern gaming computer, but just by a microprocessor. But this is enough to organize the proper operation of the motor. To learn about all the advantages and disadvantages of the injection system, you need to study it in more detail.
General design of injection system
The first direct injection systems appeared several decades ago. They allowed not only to reduce the basic fuel consumption on cars, but also significantly simplify driving. True, the complexity of the design has increased - there are many sensors and actuators that are not inherent in carburetors. The introduction of such systems became possible only thanks to the development of microelectronics. Since it is based on a control unit that analyzes thousands of signals every second.
Just think, how many pulses does the sensor alone give out? Hundreds per second, and this is a lot. In addition, they all need to be analyzed and correctly responded to. But if carburetors work solely on the basis of the simplest physical processes, such as the pressure difference in the chambers, the injector functions only thanks to electronic devices. Pressure is created not due to rarefaction in the ramp, but by forcing fuel and air into it. This will be discussed a little later, and the question will be considered which is better - an injector or carburetor on a seventh model car.
Electronic control unit
Indeed, this is the heart of any injection machine. To understand his work, it is necessary to consider the structural diagram, which includes:
- Readers (sensors).
- Actuators (IAC, petrol pump, collector heater).
- Microcontroller with the required number of input / output ports.
But the problem is that the sensors give out various signals. Some have 12 volts at the output, while others have less than one. And the problem is that on the VAZ 2107 injector fuel consumption will depend on the parameters coming from the sensors, and the microcontroller can only accept a signal in the range of 3.5-5 Volts.
Matching microcontroller with sensors
Therefore, some signals need to be amplified, while others need to be reduced. For these purposes, intermediate stages (matching devices) are used - operational amplifiers and voltage dividers. With this, everything is clear, but the microprocessor will not be able to turn on even the windings of the electromagnetic relay. For this purpose, special Darlington assemblies are used. This is a small microcircuit, it is based on amplifier stages on field-effect transistors. They work in key mode and allow switching currents up to 30 A. And this is enough to power the coil of the electromagnetic nozzle.
It is impossible to coordinate the microcontroller with the nozzles using an electromagnetic relay. The reason for this is the high pulse frequency. The relay simply will not be able to make the necessary number of switchings per second. From this point of view, the key on the field effect transistor is much more efficient.
Fuel rail
Directly mounted on the engine is the assembly responsible for injecting the air-fuel mixture into the combustion chambers - the ramp and the nozzle. On a VAZ-2107 car, the fuel consumption depends on how correctly the air is mixed with gasoline. And this process takes place precisely in the ramp. Gasoline is injected into it under pressure. Air passing through the air filter is sucked in there. Moreover, the proportion should be ideal - 14 parts of air and only one part of gasoline.
Solenoid nozzles
Below is a table of fuel consumption for an engine with a volume of 1.5 liters, but with a different injection system. Constant pressure is maintained in the ramp, gasoline is in suspension, almost a peculiar fog. Only the electromagnetic nozzle valve separates it from the combustion chamber. What kind of device is this? It consists of a coil, core and valve, which is driven by current. In carburetors, something similar also exists, the design is very similar - it is an idle solenoid valve . Functions and appearance, of course, are different. Nozzles have two states - open and closed. In the first, gasoline is injected with air into the combustion chamber.
Comparison of fuel consumption of a carburetor and injection engine with a volume of 1.5 liters | Winter | Summer |
City | Mixed cycle | City | Mixed cycle |
Carburetor | 10.5-14 l / 100 km | 10-11 l / 100 km | 9-9.5 l / 100 km | 8-8.5 l / 100 km |
Injector | 9.5-13 l / 100 km | ~ 10 l / 100 km | 7.5-8.5 l / 100 km | 6.5-7.5 l / 100 km |
Electric fuel pump
But this is the device that is responsible for ensuring that the ramp always has the necessary pressure. How to reduce fuel consumption will be described below. But it is worth noting that the electric pump does not affect this parameter. It is located directly in the tank, combined in a single housing with a gas level sensor. There is also a filter on it. People call him βdiapersβ for their external resemblance.
By the way, try to change it as often as possible, otherwise fuel lines and nozzles will become clogged. And cleaning sometimes costs a lot of money. In addition to the electric pump, there is another device that allows you to maintain constant pressure - a regulator on the ramp. With its help, excess gasoline is dumped back into the tank. Therefore, overpressure for the system is not scary.
Is an injector better or worse than a carburetor?
Convenience is the trump card of the injection system. In addition, she has a minimum fuel consumption is much lower than that of a carburetor. The reason for this is a more advanced system, control of all engine operation parameters. There are still advantages - there is no leakage. The air supply is handled by an electronic system. At high speeds, the engine throttle response is higher.
But at low speeds, unfortunately, the moment and power are lower. A very sophisticated design entails expensive maintenance. Without diagnostics, it is sometimes difficult to determine the cause of a car breakdown. Even all this data is enough to try to answer the question of which is better - an injector or a carburetor. But the final answer will still not be. On the one hand, an injector is better. And on the other, it turns out to be slightly worse.
Is it possible to reduce the consumption on the injector?
And now it's worth talking about how to reduce fuel consumption on an injection engine. The surest way is to change the firmware of the microcontroller. In this case, a new fuel card is written, according to which the engine is running. The content of air and gasoline changes, therefore, there is a loss of power. But you get a slight advantage. As a result of such manipulations on the VAZ 2107 injector, fuel consumption is reduced. True, the maximum speed, power and throttle response of the car also become less. When choosing a firmware, car owners are guided by the average indicators, which are given in the table. For comparison, data are presented for a similar engine with a carburetor injection system.