Do-it-yourself replacement of the economizer VAZ 2107
Content
Classic VAZ cars with a carburetor engine were equipped with a device called an economizer. Diagnosing a malfunction and replacing this device with your own hands is quite simple.
Appointment of the economizer VAZ 2107
The full name of the economizer is the forced idle economizer (EPKhH). From the name it is clear that its main function is to regulate the supply of fuel to the combustion chambers in idle mode.
The economizer allows you to save quite good fuel. This is especially true when driving on long descents, where the driver applies engine braking. At such times, EPHH does not allow fuel to enter the idle system. This, in turn, not only leads to a reduction in fuel consumption, but also increases traffic safety. The fact is that a car moving downhill in low gear and constantly braking the engine is much more stable on the road compared to a car rolling freely downhill at neutral speed.
Location economizer VAZ 2107
The VAZ 2107 economizer is located at the bottom of the carburetor next to the air filter.
Therefore, before dismantling the economizer, you will have to remove the air filter - there are no other ways to get to the EPHH.
The principle of operation of the economizer
Economizer VAZ 2107 consists of:
- solenoid;
- a closing actuator made of plastic and performing the functions of a conventional needle valve;
- the main idle jet.
If the accelerator pedal is not pressed, and the crankshaft rotates at a speed below 2000 rpm, the EPHH is activated and shuts off the fuel mixture supply to the idle channel. The economizer is switched on when a signal is applied to it from the control unit of the car connected to the microswitch in the ignition system.
When you press the gas pedal and the crankshaft speed is above 2000 rpm, another signal is sent to the EPHH, turning it off, and the fuel supply to the idle channel is resumed.
Video: VAZ 2107 economizer operation
Symptoms of a malfunction of the economizer VAZ 2107
There are several typical symptoms of a malfunction of the VAZ 2107 economizer:
- The engine is unstable at idle. The diaphragm in the carburetor loses its tightness, and the economizer needle valve begins to partially shut off the fuel supply.
- The engine starts with difficulty, even if it has not had time to cool down.
- Fuel consumption increases by about a third, and sometimes twice. The latter occurs if the EPHX needle valve becomes completely clogged, freezes in the open position and stops shutting off the fuel supply in a timely manner.
- An increase in fuel consumption is accompanied by a strong decrease in engine power.
- Traces of gasoline splashes appear near the power mode economizer.
The appearance of one or more of these signs indicates a high probability of an economizer malfunction and the need to replace it.
Replacement economizer VAZ 2107
To replace the VAZ 2107 economizer, you will need:
- new economizer for VAZ 2107 manufactured by DAAZ;
- set of open-end wrenches;
- set of socket heads;
- flat screwdriver.
Sequence of work
Work on replacing the EPHH VAZ 2107 is carried out in the following order.
- The engine is turned off and cools down for 15 minutes.
- Remove the negative terminal from the battery
- The socket head for 10 unscrews the bolts securing the air filter housing. The housing is carefully removed, giving access to the carburetor.
When replacing the economizer, the air filter must first be removed. - The VAZ 2107 economizer is fastened with three bolts (shown by arrows), which are unscrewed with a flat screwdriver.The economizer rests on only three bolts, but their location cannot be called convenient
- When unscrewing the EPHX mounting bolts, it should be borne in mind that there is a spring-loaded diaphragm under the economizer cover. Therefore, the cover should be held with your fingers so that the spring does not fly out.The economizer cover must be removed very carefully - there is a spring under it that can fly out
- After removing the cover from the carburetor, the spring and the economizer diaphragm are pulled out. After removing the spring, it is necessary to evaluate its elasticity and degree of wear. If it stretches with difficulty, it should be replaced along with the economizer.The diaphragm behind the economizer spring is a very small part that can be easily lost.
- The old economizer is replaced with a new one, and all removed elements are installed in the reverse order.
Economizer sensor VAZ 2107 and its purpose
Car owners usually call an economizer an economizer sensor. On the first carburetor VAZ 2107, type 18.3806 econometers were installed. These devices allowed the driver to estimate the approximate fuel consumption in different engine operating modes - at low speeds, at high speeds and at idle.
Economizer sensor location
The economizer sensor is located on the dashboard above the steering column next to the speedometer. To dismantle it, it is enough to remove the plastic panel covering the sensor.
The principle of operation of the economizer sensor
The economizer sensor is a mechanical measuring device. It is the simplest vacuum gauge that controls the level of vacuum inside the engine intake pipe, since gasoline consumption is associated with this pipe.
The sensor scale is divided into three sectors:
- Red sector. The carburetor shutters are fully open. Fuel consumption - maximum (up to 14 liters per 100 km).
- yellow sector. The carburetor shutters are about half open. Fuel consumption is average (9-10 liters per 100 km).
- Green sector. The carburetor shutters are almost completely closed. Fuel consumption is minimal (6–8 liters per 100 km).
The principle of operation of the sensor is quite simple. If the dampers in the carburetor are almost closed, the vacuum in the intake pipe increases, gasoline consumption decreases, and the gauge needle goes into the green zone. If the engine is running at high speeds, the dampers open completely, the vacuum in the pipe reaches a minimum, gasoline consumption increases, and the sensor needle is in the red sector.
Symptoms of a malfunction of the economizer sensor VAZ 2107
The failure of the economizer sensor can be determined by two signs:
- the sensor needle went into the red zone and stopped moving;
- the sensor needle reached the center of the yellow zone, stopped and began to twitch, not responding to a change in the speed of rotation of the crankshaft.
This behavior of the arrow is due to the fact that the teeth on the sensor pin are completely worn out or broken. The sensor needs to be replaced. It is not subject to repair, since there are no spare parts for it on free sale.
Replacing the economizer sensor VAZ 2107
To replace the economizer sensor, you will need:
- new sensor type 18.3806;
- flat blade screwdriver.
Economizer sensor replacement procedure
The panel that covers the sensor is quite fragile. Therefore, when dismantling it, do not make great efforts. The sensor is replaced according to the following algorithm:
- The panel above the economizer sensor is held on by four plastic latches. The tip of the screwdriver is carefully pushed into the slot above the sensor. Using a screwdriver as a lever, the panel gently slides out towards itself until a quiet click, meaning that the latch has disengaged.
- Other latches are unfastened in the same way. The sensor is accessible.Remove the economizer sensor panel carefully so as not to damage the plastic latches
- The sensor is attached with one bolt, which is unscrewed with a flat screwdriver. The sensor is removed, and the wires leading to it are disconnected manually.To remove the sensor, unscrew one mounting bolt and disconnect the wires
- The sensor is replaced with a new one. The dashboard is assembled in the reverse order.
Thus, even an inexperienced motorist can replace the forced idle economizer VAZ 2107. To do this, you just need to carefully follow the recommendations of experts.
