DIY MAF sensor repair

In detail: DIY repair of a mass air flow sensor from a real master for the site my.housecope.com.

Auto parts sellers ask for a lot of money for a mass air flow sensor. However, repairing a mass air flow sensor is not a big deal. Therefore, before listening to the seller who stubbornly insists that the mass air flow sensor is not restored, but changed, try your luck and repair this device.

The MAF sensor plays a very important role. The controller will mix fuel and air in the correct proportion only if it receives accurate data on the engine air consumption.

If the sensor gives false data, the air-fuel mixture will become of poor quality for the given engine mode and the engine will lose power, fuel consumption will increase, the dynamics and "response" of the car will worsen.

In domestic cars, the most popular problem with mass air flow sensors lies in the crankcase ventilation system. This system has two circuits. One of them is designed to work with an open throttle, the smaller one with a closed one.

When the throttle is closed, crankcase gases are sucked into the space behind the throttle along a line with a diameter of 1.5 mm. Some of these gases move along the idle line and come into contact with the film coating of the sensor resistor.

Also, this resistor is influenced by oscillations of gases in the intake tract. Resin accumulates on the surface of the resistor, and it begins to "lie". The idle speed control will also begin to wedge and seize, especially when starting the engine.

Video (click to play).

If there is no special diagnostic device for the mass air flow sensor, then you can completely do with a voltmeter with a 2 V scale. Between the seal and the yellow wire, we insert a pin into contact until it stops. We turn on the ignition and measure the contact voltage. Ideally 0.99 V. Deviations of 0.03 volts are still allowed, but not anymore.

If the value does not suit us, then we are in no hurry to change the sensor. Using the pliers, we unscrew the fastening elements of the block, since they are quite tricky, instead of them, you can subsequently wrap the usual ones, under a Phillips screwdriver. Prepare an aerosol carburetor cleaner in advance, warm its tube with a match and bend it at a right angle.

We cut it off so that the jet beats to the side, and the tube itself is straight. We introduce it to a depth of about 10 mm into the upper channel of the sensor and my resistor. Let's wait a couple of seconds and repeat the manipulation. Never try to mechanically clean the resistor with swabs, sticks and compressed air.

After the measuring element has dried, we put it back into the case and measure the voltage. If it has not changed, then it looks like the DMRV will actually have to be replaced. If the voltage is normal, the efforts are justified.

The price of the mass air flow sensor (MAF) stands out among other car parts, and is about 2,000 rubles. If the diagnostics revealed an error in the mass air flow sensor, then do not rush to change it, try restore the mass air flow sensor yourself .

As practice shows, out of 10 sensors using cleaning it is possible to restore 8. In any case, it is worth trying, because the price of a cleaning agent is 10-15 times less than the cost of a new sensor.

Mass air flow cleaning video :

By the way, before you buy a new sensor or try repair the DMRV... it would be more correct to first diagnose it.

How quickly the mass air flow sensor will clog depends directly on the degree of contamination of the air filter on which it is located.If the filter is not clogged, then it effectively cleans the air of all dust particles and the mass air flow sensor does not come into contact with fine mechanical impurities, however, if the air filter is worn out or simply not of high quality, the sensor will get dirty very quickly.

Cleaning the mass air flow sensor is performed in the following cases:

The fourteenth is very dull at the moment of acceleration, any jerking, jerking or dips in revolutions indicate that something is wrong with the sensor;
The engine runs intermittently at idle, or vice versa, at idle, the revolutions are excessively off scale;
Fuel consumption has increased (owners of VAZ-2114 often write that with a dirty sensor, gasoline consumption can increase from 9-10 to 15 liters);
The engine refuses to start.

Flushing the mass air flow sensor on the VAZ 2114 solves any of these problems, if, of course, the sensor is its only cause.

To determine that this particular unit is faulty and the MAF sensor needs to be flushed and repaired, it is necessary to check the mass air flow sensor with a multimeter.

A multimeter, also known as a tester, is an electronic device that can be purchased at any car dealership at a price of 400-600 rubles for the simplest models (their functionality will be quite enough for us). It is not inexpensive and will come in handy in the garage more than once - they can check any sensors and electronic systems of the car.

The serviceability of the mass air flow sensor is checked as follows:

We transfer the tester to the voltmeter mode and set the upper limit of sensitivity to 2 Volts;
We short-circuit the multimeter probes on the yellow and green wires (they are located in the sensor connection socket);
We activate the ignition (there is no need to start the engine) and look at the tester reading.

If the tester has confirmed that the voltage between the yellow and green contacts fluctuates in the range from 0.0099 to 0.02, then everything is fine with the unit.

If the device is breathing hard due to wear or contamination of sensitive parts, the tester will show a maximum voltage of 0.03 V, in which case it is necessary to clean the mass air flow sensor on the VAZ 2114.

In the case when the readings of the multimeter are much higher than the upper voltage limit, in the range of 0.045-0.5 V, or much less than the minimum - 0.09-0.095 V, the probability that flushing the mass air flow sensor will give a result of about 50%.

Checking with a multimeter is not a dogma, there are other methods.

There is another simple method to check the performance of this node, which can be used in the absence of a multimeter. Just remove the mass air flow sensor and close the air duct valve, turn on the fourteenth and run it at 2 thousand revolutions. If you feel that in the absence of a sensor, the car behaves much better on the road, then the problem is in it.

The reason why the mass air flow sensor fails is the contamination of its sensitive element, which is a wire or a platinum resistor (depending on the type of device).

Platinum sensors are very easily damaged by the wrong cleaning approach. If this happens, the device can simply be thrown into a landfill, as it will be impossible to restore them.

When choosing what to clean the mass air flow sensor, never use the following fluids:

Products containing acetone;
Ketones and any other artificial solvents;
Liquids containing sulfuric esters.

Also don't tryclean the mass air flow sensor on the VAZ 2114with the help of cotton shelves for cleaning the ears or a toothbrush - any mechanical contact with the sensitive element of the device is unacceptable.

The choice of fluid for flushing the mass air flow sensor, in fact, has three options:

Regular medical alcohol without any impurities;
Acetone-free carburetor cleaner;
WD-40.

Ideally, it is best to use WD-40 and rubbing alcohol at the same time (diluted with distilled water in a ratio of 5 to 1): first, a VDshka is applied to the sensitive contacts, after which it is washed off with alcohol.

Having decided how to flush the mass air flow sensor, you can proceed directly to the procedure itself.

In addition to the cleaning liquid, you will need a regular syringe with a needle for 10-20 cubes, a screwdriver and a 10 wrench to dismantle the sensor.

We dismantle the device: we remove the block connected to the sensor with the power wires (on its lower part there is a locking button, which must be pressed, after which the block can be simply pulled out) and, with a 10 key, unscrew the two screws that fix the sensor on the air filter housing;
In the place where the block with wires is connected to the sensor, there are two screws connecting the parts of its protective casing, they must be unscrewed with a Phillips screwdriver, after which you can disassemble the casing and pull out the DMRV itself;
All sensitive elements of the sensor (thermosensor wire, contacts) are washed with a cleaning liquid. If it is VD-40 or a carburetor cleaner supplied from a can, carefully monitor the pressure of the jet on the elements of the device, it should not be too strong (the optimal distance of the can nozzle from the structure is 5-10 centimeters);
Apply VD-40 for the first time, let it dry for 30-40 seconds and reapply (2-3 times, as a rule, is enough);
Then, using a syringe, rinse the sensitive elements and sensor contacts with a mixture of medical alcohol and distilled water.

This completes the procedure. Knowing how to clean a mass air flow sensor on a VAZ 2114, all the work can be done in 15-20 minutes. It remains only to install the device in place and check its performance.

This technique can be used, among other things, on the VAZ 2114 and VAZ 2115.

The MAF sensor plays a very important role. The controller will mix fuel and air in the correct proportion only if it receives accurate data on the engine air consumption.

We cut it off so that the jet beats to the side, and the tube itself is straight. We introduce it to a depth of about 10 mm into the upper channel of the sensor and my resistor. Let's wait a couple of seconds and repeat the manipulation.Never try to mechanically clean the resistor with swabs, sticks and compressed air.

First you need to remove the pipe from the mass air flow sensor (instructions). Next, you need to remove the mass air flow sensor from the pipe, otherwise it will not be possible to perform high-quality cleaning. To remove the sensor, you will need a set of sprocket keys. We unscrew the screws and take out the sensor from the pipe.

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You can often find that the inside of the sensor itself is covered with oil, our task is to make everything perfectly clean. To clear the mass air flow sensor a carburetor cleaner is suitable for this plaque. On the inside of the film, there are 2-3 sensors, which are small wires that are attached with a special resin. Gently spray on this sensitive element so as not to damage it. We are waiting for a while until the product dries. We repeat this procedure several times, depending on the pollution of the mass air flow sensor. To accelerate drying, it is allowed to use a compressor / canister with compressed air, but the point is not in high pressure, but in blowing for drying.

Flushing the mass air flow sensor can be done with other means, for example, alcohol. In addition to the sensor, it is worth paying attention to both the mesh of the pipe and its inner surface. If necessary, we clean the DMRV branch pipe from dirt, debris and dust.
On this repair of DMRV finished. We carry out the assembly in reverse order and change the air filter.

Mass air flow cleaning video:

By the way, before you buy a new sensor or try repair the DMRV, it would be more correct to first diagnose it.

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Have you tried to restore the mass air flow sensor?

For a mass air flow sensor, they ask for a considerable price, and according to the laws of the market, this should be justified. It's simple, however! To a large extent, this is a payment for our ignorance - we cannot imagine how the DMRV works ... and why it stops working. And also - for the opinion imposed on us by the market dealers: if the DMRV got mocked - buy a new one!

The role of the DMRV can hardly be overestimated. In order for the controller to accurately orchestrate the injectors and ignition, it must know as accurately as possible the actual air flow rate of the engine. If the mass air flow sensor begins to lie, the engine loses power, fuel consumption and exhaust toxicity increase, and the acceleration dynamics deteriorate.

One of the common reasons for the malfunctioning of the mass air flow sensor on the "dozens" lies in the peculiarities of the engine crankcase ventilation system. There are two circuits in it - a large one, which operates with an open throttle, and a small one for idling, when the throttle is closed. In the latter case, blow-by gases are sucked into the throttle space through a channel with a hole diameter of 1.5 mm. Some of them pass along the idle line, through its regulator, at the same time in contact with the delicate film resistor of the DMRV. In addition, the latter is located in the zone of action of reverse oscillations of gases in the intake tract. Resin deposits change the characteristics of the resistor - and the sensor is out of tune. By this time, the idle speed regulator also begins to be capricious in its own way - it jams, wedges, especially when starting the engine.

Usually, the DMRV is checked with a diagnostic device (for example, DST-6), but we will manage with a digital multimeter with a scale of up to 2 V. Insert a pin between the rubber seal and the yellow wire until it stops in contact (photo 1). Now turn on the ignition and measure the voltage at this contact. Ideally, it should turn out to be 0.99 V. Taking into account the measurement errors - no more than 1.03 V. If it is higher, someone immediately replaces the sensor with a new one. We will not be in a hurry. Having unscrewed the tricky self-tapping screws for fastening the measuring element of the sensor with pliers, we will instead select simple (4.9 x 20) for a Phillips screwdriver. This will make it easier to service the machine in the future. And we will work with the removed element. Let's prepare a washing device - an aerosol carburetor cleaner, the tube of which, heated in a match flame, will be bent at an angle of 90 °. Then we cut it off so that the jet is knocked out to the side, and the tube itself remains straight (photo 2). Having introduced it to a depth of 10 mm into the upper channel of the DMRV measuring element, we rinse the resistor. In a few seconds - again. As a rule, more is not required. Please note that the resistor does not allow any force effect - forget about cotton swabs, brushes, compressed air.

Letting the traces of the cleaner dry, insert the sensor into the housing and repeat the voltage measurements. Hasn't changed? Apparently, the DMRV resource is really exhausted. Usually, the "top ten" need to go through 80-90 thousand, or even more. If the tension has dropped to normal, we will drive. Of course, after flushing the sensor in this way, some of the characteristics of the engine may change. You will need to re-check the toxicity of the exhaust, in some cases (if the system allows it) to adjust it - and so on. Well, is it possible to ease the operating conditions of the DMRV and extend its service life? We will talk about this another time.

All modern engines are equipped with a mass air flow sensor (decoding - mass air flow sensor). This sensor is required for normal vehicle operation. Signs of malfunction of the mass air flow sensor appear in unstable engine operation, as the fuel mixture is not formed correctly. You cannot drive a car with an inoperative sensor, this can lead to other, more serious damage.

Mass air flow sensor device

The DMRV sensor is responsible for ensuring that the fuel mixture is formed correctly based on the amount of air consumed.

The DMRV sensor is responsible for ensuring that the fuel mixture is formed correctly based on the amount of air consumed. It determines how much gasoline should enter the cylinders of the block through the injectors, giving appropriate signals to electronic control unit... In order to determine the amount of air that passes to the throttle valve, highly sensitive threads are built into the sensor. The mass air flow sensor is located just behind the air filter, and determines the amount of already cleaned air. Mass air flow sensor is installed on all modern gasoline and diesel engines.
In older engines without a mass air flow sensor, the fuel mixture is formed only on the basis of throttle position... That is, the harder the driver presses the accelerator pedal, the richer the mixture. This does not take into account the quality and density of air, and the engine does not always work optimally when temperature or other environmental factors change.

The location of the DMRV sensor

Most often, the MAF sensor does not work correctly due to clogging.

Clogging. Most often, the mass air flow sensor does not work correctly due to clogging. Crankcase gases from the throttle valve, or propane gas, when connected to the throttle valve unit (Euro-2), can get here along with air. As a result, a layer of deposits forms on the threads that read the amount of air.
Broken threads. Sensor filaments can be damaged due to wear or misuse. Like any other device, the mass air flow sensor has a limited service life, and, as a rule, it is enough for 100-150 thousand mileage. In addition, the sensor can break due to the detonation of the gas in the throttle assembly.

The engine runs intermittently at idle speed. If the sensor is faulty, the idle speed of the car will be unstable. Especially when starting the engine before warming up, there will be strong fluctuations in rpm. Sometimes the engine just stalls if you add RPM with the accelerator pedal.
Turnovers freeze. Also, the revolutions can hover at around 2-3 thousand with a complete release of the gas and hold that way for a few seconds.
Lost engine thrust. If the faulty sensor depletes the mixture, the engine power will decrease. The car will not accelerate well and go downhill.
Increased fuel consumption. A low signal from the MAF sensor can cause the mixture to be too rich, resulting in an increase in flow rate of 20-30%.

When you turn off the mass air flow sensor, you can deceive the ECU - it turns on to emergency operation - according to a simplified algorithm.If the mass air flow sensor is faulty and it was not possible to clean it, it is necessary to replace it with a new one. Depending on the car model, the price of a mass air flow sensor is 3-5 thousand rubles.

Disconnect the battery. In order not to damage the power supply circuit, it is advisable to perform all procedures with the battery disconnected.

Dismantle the old sensor. First, the plug with the wiring is disconnected, then the mount is unscrewed and the sensor is removed from the duct.

Install a new sensor. Place the new sensor carefully without touching the threads inside the sensor. Then the plug with wires is connected. The sensors have a standard connector for every car brand.

Connect the battery.

When should you clean the MAF sensor?
It is cleaned only when it gets clogged with dirt, and most often the platinum spirals get dirty because of the heavily soiled air filter, all the dirt literally flies on them, and therefore they have to be cleaned, but always remember what kind of spirals in no case should you touch with your hands or something else rough (with a brush for brushing your teeth, for example), in this case, your sensor may immediately fail, it is better not to touch these spirals at all, but just to spray liquid on them that's all, but you need to spray until all the drops dripping from the spirals become clean, usually 2-3 times of cleaning with a carburetor cleaner is enough to bring the sensor back to life.

Note!
Usually, if this sensor malfunctions, the "Check Engine" lamp pops up, which says that something is wrong with the engine (see how this lamp looks in the photo below, it is indicated by an arrow on it), but not in all cases it can light up, for example, if the sensor will not die much and problems will already occur with the car, then this lamp may not even light up, thus you will think to the last that everything is in order with the engine!

Note!
Many people stop and say there is no need to clean this sensor, in fact, everything is true because it is very sensitive and if you make some mistake, you can forever remain without this sensor and go to a car shop for a new one, so when cleaning, be careful and proceed with it only if you are 100% sure that this particular sensor is out of order, so we do not recommend touching a serviceable sensor at all, otherwise you can simply damage it and go to a car shop for a new one!

1) At the beginning of the operation, you will first need to remove the sensor itself, in fact, the sensor is removed quite easily, for more detailed instructions on how to remove it, check out the article called "Replacing the Mass Air Flow Sensor with a VAZ", everything is described there.

Note!
In the article to which the link is given above, in addition, it describes how to correctly check the sensor for operability, so study it in more detail and only then proceed to this article!

2) Then, when the sensor is already removed, you will need to disassemble it, for disassembly you need a special asterisk key, in the same case if you do not have one, then using pliers you can carefully unscrew the two screws that secure the sensor itself, for this take in hands with the pliers and unscrew the two screws that secure the sensor itself to the case (the screws are indicated by the arrows), but you need to unscrew the screws in this way, first tighten the screws well with the pliers and then twist the pliers and the case itself in the right direction and twist until the screws do not budge, but there it will already be possible to unscrew them easily with the help of your hands.

Note!
When all the screws are unscrewed, very carefully without damaging anything (There are spirals on the sensor itself and one of them that goes for heating is not protected by anything), so when you pull out the sensor do not damage this spiral, they are very delicate, there are even cases when after wiping With a rag, the sensor immediately fails, so take this into account! (By the way, the very spiral that is not protected by anything, you can see in the photo below it is shown on it with an arrow)

3) Now take in your hands a carburetor cleaner (How to choose the right cleaner was shown in the video at the end of the article) and them from top to bottom (Make sure first that the pressure from the cleaner is not too strong, if there is a lot of pressure in the cleaner and thus, the jet beats very, very strong, then in this case, we recommend that you rinse the sensor at a decent distance so as not to damage it) clean the sensor, you may not splash too much on the sensor case (But the case is still the most dirty) but still apply a little liquid , and pay special attention to the platinum spirals, which you will need to clean from the dust and dirt accumulated on it.

Note!
This procedure is best done gradually, that is, not so, sat down and for 5 minutes of continuous cleaning, cleaned the sensor, it is better to sit down and gradually clean the sensor in 10-15 minutes using a pause between approaches, that is, remove all dirt from it for the first time (Work in the area of 1 mine with the sensor), then let it dry and again in the area of 1 minute remove all remaining dirt from it, well, the third time just let it dry in the same way and rinse it from this dirt and after that you can collect the sensor back and see if it works for you or not! (When you clean it for the last time, make sure that the drops drip from it clean and only then stop cleaning it)

Additional video clip:
You can see more detailed information on how to clean the sensor in the video below, it explains everything in detail, but for example, the sensor from the Niva car is taken, but despite this, all the air flow sensors that are installed on cars are very similar to each other, therefore you do not need to pay special attention to the car.

Note!
If you are wondering which carburetor cleaner to choose for cleaning the sensor, then check out the video below:

Mass air flow sensor is a mass air flow sensor. It is an electronic device that is used to count the amount of air flowing from the air filter into the cylinders.

Depending on the volume of air passing through the sensor for a certain time period, the corresponding information is transmitted to the electronic control unit by means of a pulse signal. According to the pulse frequency, the ECU determines the ratio of fuel and air in the fuel-air mixture, and monitors the operation of the injection of the injectors.

On the VAZ 2110, this sensor is located at the outlet of the air filter, connecting it to the corrugation.

There are several signs by which you can determine the malfunction of the mass air flow sensor:

The check engine light comes on on the instrument panel;
Fuel consumption increases noticeably;
The car loses in dynamics and power, failures occur when trying to increase engine speed;
Difficulties arise when starting on a hot engine.

But what exactly causes these symptoms? The reasons for the sensor malfunction are as follows.

The connector has lost contact.
The air filter, grilles or thermal detectors of the sensor are dirty.
Mechanical damage to the sensor elements.

When the first signs of a malfunction occur, be sure to check the mass air flow sensor, and then, depending on the situation, clean or replace the device.

Now how to check our sensor.Today, there are two main methods of checking the mass air flow sensor.

The engine is tested in operation with the MAF sensor disconnected. It is enough just to disconnect power from the regulator and start the motor. When the mass air flow sensor is absent during start-up, the electronic control unit turns on the power unit in emergency mode. The revs are adjustable to 1500 revs. After disconnecting the sensor, drive a few kilometers, evaluate the dynamics, power. If the engine is working properly, then the sensor is the cause of the symptoms.

The second method will require the use of an automotive tester or voltmeter. After starting the ignition, do not start the engine. A voltage threshold of 2V is set on the tester. The positive probe connects to the yellow wire on the sensor connector, and the black probe connects to the green wire. Further, be guided by the table.

State of the DMRVThe sensor is functioning normallyNot ideal, but still acceptable voltage indicatorsMaximum permissible values, which indicate an imminent breakdown of the sensorMass air flow sensor is out of order, needs to be replaced Image - DIY MAF sensor repair

Quite often, you can avoid replacing the mass air flow sensor by simply cleaning this engine element.

Do-it-yourself cleaning should be done in this way:

Remove the pipe from the MAF sensor;

Now remove the sensor from the tube. Otherwise, high-quality flushing will not work;

To remove the sensor, arm yourself in advance with the "asterisk" keys. Finding such kits is not a problem;

Unscrew all fasteners, remove the sensor from the pipe and assess its external condition;

There are often traces of oil on the sensor. The task of cleaning is to make the device as good as new;

To clean the mass air flow sensor, a carburetor cleaner is often used;

Inside the film there are sensors, which are small wires attached to a special resin. These elements must be carefully sprinkled with a cleaner so as not to damage the device;