Engine

Author temass

Date
Jul 18, 2017
2,097

Share

Considering that the engine is the heart of the car, interruptions also occur with it, which we recognize by the violation of speed. You can find out that the idle speed is floating from the tachometer readings or from the sound of the engine, the hum of which periodically subsides or intensifies. This is also indicated by the increasing, then weakening vibrations felt in the cabin.

• Reasons for VAZ idle instability on the carburetor
• Why does the idle speed on the injector fluctuate a lot?
• Eliminating the causes of unstable engine idling on the injector
• We check the air filter with electrical wiring at floating speed XX
• Checking the exhaust manifold during unstable idling
• Clean the throttle valve if the idle speed fluctuates
• Instability of idle speed with HBO
• The idle speed of a diesel engine fluctuates
• Bottom line

Description of the problem

The malfunction manifests itself in jerking and floating engine speed, when the tachometer needle can jump from 500 rpm to 1500 rpm and even higher. During normal engine operation, the needle first rises to a level of 2000–2500 rpm in warm-up mode, and then should remain at 700–900 rpm. If there is no tachometer on the dashboard, floating speed can be determined by the sound of the power unit (the roar of the engine either increases or decreases), as well as by the vibrations penetrating the cabin.

As a rule, after the engine warms up, the problem disappears. However, at the next cold start, exactly the same picture occurs: the speed of the power unit again jumps in a wide range. And if the first time can still be attributed to an accident, then the second and subsequent cases are a reason to contact for repairs or to fix the problem yourself.

Unstable engine operation or why the idle speed fluctuates

Welcome, friends, to the DIY car repair website. One of the very common problems found on almost all cars is floating idle speed.

RPM fluctuates at idle

Such a minor (at first glance) malfunction is very annoying and can cause a lot of inconvenience on the road. For example, at an intersection, a car can stall at any time when the speed decreases.

THIS IS INTERESTING: How to remove the coolant temperature sensor

The driver, in turn, has to constantly apply pressure to the gas to keep the engine in good shape.

How is everything going?

When everything is fine, you start the car and wait for the engine to warm up. In this case, the tachometer needle is at the level of 2-2.5 thousand revolutions and gradually drops during warming up to 800-900 revolutions per minute.

But it also happens differently. Immediately after starting the engine or after some time, you notice that the engine speed is fluctuating. In this case, you can do nothing - the machine seems to live its own life.

The range of oscillations can be large - from 500 to 1,500 rpm. As a rule, after 5-10 minutes this problem goes away, but the next time everything repeats again and again.

In such a situation, you cannot remain idle - you must find out why the idle speed is floating. This is the only way to eliminate the problem and forget about it like a bad dream.

Idle speed fluctuates, causes, malfunctions

Understand that there are many reasons for the engine to be unstable at idle. In this case, much depends on the type of engine - carburetor, injection or diesel. Let's look at each of the options:

1. Let's start with domestic cars with a carburetor engine (for example, VAZ 2107 or VAZ 2109). So, why do the idle speeds fluctuate in our favorite “classics”.

There are several reasons:

The engine idle speed is incorrectly adjusted or it has gone astray during operation. At the same time, the setting shifted towards depletion of the fuel assembly (fuel-air mixture).

In this case, you just need to adjust the speed to 800-900 rpm; read the article on adjusting the carburetor yourself.

The carburetor solenoid valve has failed. In this case, the motor will only work when the choke is extended. If you remove the choke, the engine will immediately stall.

The idle air system jets or channels are dirty. If this happens, the fuel is starved of air as it enters the engine. The problem is often solved by simply cleaning the jet.

The sucking of “extra” air into the carburetor system inevitably leads to a lean mixture. As a result, the engine begins to stall and stall.

The following problems are also possible:

• Excessive (low) gasoline level in the float chamber.
• The air filter is clogged (here you can save yourself with a regular replacement).

2. In modern cars with an injection engine and electronic fuel injection, such as the VAZ 2110-2115, no less reasons can be identified. In this case, problems are often associated with the breakdown of one of the sensors.

What happens? The electronic control unit tries to read information and does not receive it. As a result, malfunctions in the operation of the power unit appear, and instability in speed appears.

But let's highlight all the main reasons. There are several of them:

• Problems with spark plugs (poor quality, wear, contamination);
• interruptions in the air supply (failure of the mass air flow sensor);
• air intake from outside into the intake system;
• damage (defect) of high-voltage wires;
• failure of the XX regulator;
• EGR sensor malfunction.

When the idle speed is floating, the first thing to do is check the idle speed control. Most often it is located next to another sensor that controls the throttle position. Checking is carried out using a multimeter.

If the sensor resistance is outside the normal range (40-80 Ohms), then there is a high probability of IAC failure.

If everything is normal with the idle speed control, you can move on to the next “suspect” - the mass air flow sensor.

To check the device, you need to disconnect the connector from it and start the engine. In this case, the engine speed will be around 1,500 rpm. If the dynamics only improve while driving, then the mass air flow sensor is really faulty.

The EGR valve is responsible for the movement of exhaust gases. The sensor's task is to return some of the gases back to the combustion chamber. This is necessary to ensure complete combustion of fuel and minimal harm from exhaust gases. Cleaning the valve seat is often enough to fix the problem.

3. In diesel cars, the cause of floating idle speed may be the appearance of corrosion on the moving blades in the power pump. As a result, they simply jam and stop coping with their function.

To prevent this from happening, you need to add at least a little motor oil to the fuel tank (200-250 grams is enough). This is enough to protect the metal elements with a thin layer of oil.

Now floating idle speeds will not cause you to panic, because you know what causes them and what needs to be done. Good luck on the roads and of course no breakdowns.

(7 voice, 3,14

Source: https://RemontAvtoVaz.ru/avto-sovety/nestabilnaya-rabota-dvigatelya-ili-pochemu-plavayut-oboroty-na-xolostom-xodu.html

Instability of speed in intermediate modes

In diesel power units, floating speeds in operating modes most often appear due to the formation of corrosion on the plungers of the high-pressure fuel pump. Rust on these parts appears due to the presence of water in the fuel. Because of this, the diesel engine speed fluctuates even at idle.

The consequences of these considered reasons are:

• High fuel consumption.
• Release of a large amount of carbon monoxide into the external environment.
• Wear of parts of the fuel system and air supply to the engine.

To prevent such consequences, it is necessary to regularly check the functioning of the considered sensors and systems. If a malfunction does occur, you should immediately take measures to repair it.

The considered reasons for floating engine speed are only the main ones, and there are many other reasons. They will help you understand the operation of the car and prevent unnecessary spending of money on auto repair shops. Without understanding the operating features of the power unit, we may be subject to fraudulent actions by car repair specialists. Often, cheap repairs turn into large financial expenses that could not have been made. You should study in more detail the structure and operation of your machine, and it will answer you with a long service life.

Violations of system sealing

Air intake into the intake system may cause floating speed. You can identify such a malfunction yourself by visually inspecting the following elements:

1. Vacuum hoses and brake boosters.
2. Gaskets on the throttle body and intake manifold.
3. Injector seals.
4. Throttle assembly.

It will be useful to carry out an inspection while the vehicle is idling. In addition to the above-mentioned automotive components, it is advisable to inspect the components adjacent to them.

The next reason why engine speeds fluctuate is decompression of the cylinder block. Only one of the cylinders may be the specific source of the problem. You can check the compression level using a pressure gauge connected to the spark plug connector. The spark plugs themselves will need to be removed during the test. The test must be performed for each of the spark plugs, and the results must be checked against factory standards.

Engine idle mode

What engine speed should be at idle (idle)? Average performance for most cars is in the range of 700 - 900 rpm. In idle mode, the internal combustion engine does not experience significant loads, and fuel consumption is minimal.

When set to XX, the engine receives minimal loads, and fuel is consumed sparingly.

Adjusted idle speed is necessary: ​​when warming up the engine, idle time in traffic jams in neutral gear and when the heating stove is running without moving the vehicle.

A forced increase in speed when starting a cold engine has its own advantage - the internal combustion engine lubricant acquires the necessary fluidity when quickly heating up. If the XX regulator breaks down, you can use the gas pedal, but it is better to undergo comprehensive diagnostics and eliminate the cause of the floating speed at idle.

Situations arise when the engine simply cannot be turned off due to a breakdown of the starter, generator, or a dead battery.

When driving on the highway, the jump in revs is imperceptible, but in city mode it causes a lot of worries and unnecessary nerves.

Why does the idle speed on the injector fluctuate a lot?

If the engine speed jumps at idle speed of an injection engine, the root cause should be looked for in the sensors. For cars equipped with an injector, the ECU is responsible for fuel injection. If any of the sensors fails, the functionality of the control unit is automatically disrupted, leading to the submission of incorrect commands and, accordingly, the appearance of a problem. The most common reasons why the idle speed on the injector fluctuates can be as follows:

• sensor or IAC malfunction;
• problems with the mass air flow sensor;
• EGR sensor failure;
• air filter clogged;
• air intake into the intake system;
• faulty spark plugs;
• violation of the integrity of the electrical wiring of the sensors.

Of course, the easiest solution would be to contact a service station mechanic, although every car enthusiast can independently fix the problem in which the speed fluctuates.

Signs of unstable idle

The cause of the malfunction may also be in the automobile command center - the electronic control unit (ECU). Data from various sensors is transmitted to the ECU. If data from any sensor is not supplied or is supplied incorrectly, the computer incorrectly adjusts the fuel dose, which is why the speed fluctuates.

We recommend: How to determine what is knocking in the engine

Therefore, with floating speed XX, you need to check the following:

• idle speed sensor;
• fuel and air consumption;
• exhaust gas recirculation valve;
• throttle valve, whether it responds in time.

Recently published material about the throttle position sensor. Read it, it might come in handy.

If all electronic sensors are in order, you need to check the parts and assemblies for mechanical damage.

If the nozzle is clogged, then a rich mixture will be supplied to the combustion chambers of the cylinders, hence the engine speed will be very low.

Cleaning or replacing spark plugs. Their service life is from 50 to 100 thousand kilometers.

If the insulation of the magnetic valve is worn out or burned out, you must first go to a car service center and repair the damage.

Now there are few cars with carburetor engines, but if you have a carburetor engine, then you need to check the location of the floats and adjust the fuel level. If there is a drip of engine oil on the engine, it means the gasket has burned out or the cylinder head (cylinder head) was not tightened with the proper torque.

Why do the speeds fluctuate on an injection engine?

Modern injection cars are, of course, much more complex systems than their carburetor predecessors, and therefore, often floating engine speeds, including at idle, are the result of failure or inadequate operation of one of the electronic components. For example, the mass air flow sensor, called an air flow meter among motorists, can become clogged with dust, in which case it supplies incorrect data to the electronic engine control unit. This situation can very well cause floating idle speed.

In addition, in injection cars, a special device is installed, which is called an idle speed regulator. This regulator opens and closes the so-called bypass channel. This passage is designed to allow air to flow into the engine when the throttle is closed. Accordingly, if the regulator does not work correctly, or does not work at all, the engine does not behave adequately, namely at idle, in contrast to the situation when the air flow meter is acting up, because problems will also be observed in other operating modes of the power unit.

In some cases, the causes of floating speed may be breakdowns of the throttle position sensors or crankshaft position sensors. But again, the problems here are not limited to idle mode.

Spark plugs, or rather their wear or burnt electrodes, can also be manifested by floating engine speeds at idle. And of course, the engine will start to fail if there is a breakdown in one of the high-voltage wires going to the spark plugs.

A clogged injector is quite capable of making itself felt precisely by spontaneous changes in idle speed. Also sometimes, the problem is a broken EGR valve. Well, again, clogged air or fuel filters, or abnormal air leaks, can become a problem due to which the idle speed fluctuates.

On some cars, special engine heaters are installed. These are devices that increase engine speed to warm it up as quickly as possible. If this device fails, the speed must simply float, precisely at idle.

Causes

Unstable engine speed at idle.

Possible reasons for unstable idle speed are:

1. Air in the system.
2. Low starter speed, fuel quality, compression.
3. Fuel injection pump malfunction, lack or insufficient fuel supply. Perhaps the uniformity of supply of the mixture under the piston is affected.
4. Changes in injection timing and fuel compression ratio.

Each of the reasons is based on a variety of arguments and signs.

Air in the system

The presence of air in which:

• The fine filter element becomes clogged or the pump sucks air from cracks, holes, loose connections, or other defects.

  One of the reasons for air leaks is a clogged fuel filter element.

The reason is wear of the pump shaft seal, through which air leaks.

• It gets in at high performance of the fuel injection pump, when the filter cannot cope with its functions (filtration). That is, air vacuum occurs.
• Weak density of pipe connections located before and after the fuel pump.
• Contamination of the tank ventilation system.

Video about solving the problem of air leaks diesel SsangYong Kyron 2.0 XDI

Low starter speed, fuel quality, compression

Reduced starting speed

• Starter malfunction (armature, bushing), minimum shaft speed.

  3 main units that most often fail: 1 - brush unit; 2 - traction relay; 3 - armature collector.

• Sulfation (oxidation) of battery terminals, which oxidize power wires, causing a loose connection between the “mass” and the body. Loose contact often causes wires to heat up.

  The reason for sulfation of battery terminals is poor contact.

• Possibility of tightly assembled engine, generator braking, pump via belt drive.
• Lubricant used (thick).
• The battery is discharged due to the points stated above.

Fuel quality

Low quality diesel fuel will inevitably damage the engine . Operating defects begin with pressure valves. The lean mixture, falling under the piston, burns partially. Part of it penetrates under the plunger. The situation is worsened by the fact that the mixture is poorly formed at high speeds.

The fact of filter clogging, poor quality of injectors and cetane number bring the engine, to put it mildly, to complete technical exhaustion.

Compression

• Called air filter clogged, defective head gasket (broken or of non-standard thickness), wear of the cylinder walls.

  A loss of compression can be caused by a broken cylinder head gasket.

• Valves burning, jamming of the rod, loosening of the seat in place.

  Compression drops due to burnt out valves.

• The piston ring is broken ; their locks are installed in the same plane.
• Violation camshaft installation according to marks, wear on the back surface of the cam, defective shaft.

  Camshaft cam wear.

Fuel injection pump malfunction, lack or insufficient fuel supply

1. The reason is the low cetane number of the fuel , which contributes to an increase in the combustion rate (induction period), with a subsequent deterioration in starting a diesel engine.
2. Signs of viscosity , density of diesel fuel, leads to poor-quality atomization, deterioration in the formation of the mixture. At the same time, the length of the torch is distorted, and incomplete combustion of the fuel occurs. Carbon deposits form, smoke appears from the muffler and, as a result, a decrease in the economical operation of the car.
3. Presence of water in fuel.

Cause of insufficient or incomplete supply of mixture

1. Injector malfunction, weak fastening, wear of the plungers, problems with the regulator reducing the flow rate through the nozzles are serious problems that cause a floating idle mode.

   Faulty injectors cause floating speed.

2. Air leaks , its presence in the power system, dirty fuel filter, poor ventilation of the engine block.
3. the crankshaft speed The appearance of air vacuum, disruption of unit ventilation.

Changes in injection timing and fuel compression ratio

Injection timing, compression ratio

1. Due to the presence of air in the system, which leads to injection delay.
2. The reason is also injection pressure , which causes early or late fuel supply. The situation affects the residual pressure in the fuel pump. The injection period is significantly affected by a damaged injector cross-section, loss of hydraulic density with late injection, and also problems with the fuel advance element.
3. A commonplace sign is the installation of a fuel injection pump on the engine, loosening the pump drive belt tension, wear of the cam shaft.

   The timing of fuel injection may vary due to the tension of the injection pump belt.

We recommend: Express engine oil change: why it can be dangerous

Video on how to set the ignition on a diesel engine (injection timing)

Seemingly simple violations

1. Using a low-quality gasket, or more often laying two at once.
2. Rotating the connecting rod bearing, which leads to knocking in the engine crankcase, rapid failure of the crankshaft, cylinder and piston group.

   Rotated connecting rod bearing.

3. The use of defective connecting rods, sometimes deformed, pistons of unknown origin.
4. The plane of the head and cylinder block are ground above the required standard.

Compression ratio

Calculation of the compression ratio and combustion chamber volume.

It is measured by the ratio of the volume of the cylinder when the piston is at BDC to the volume of the combustion chamber, that is, when the piston is at TDC. It is determined, for example, for a diesel engine, as 18÷22 to 1 . This value indicates efficient operation of the engine, since complete combustion of the mixture occurs, high pressure and compression. This is an economical consumption of diesel fuel coupled with an increase in power. The latter indicator is achieved by reducing the volume of the combustion chamber.

This can be obtained by boring the cylinder block. That is, increasing the compression ratio reduces the volume of fuel combustion.

Video about the reasons for floating revolutions

Diagnostics of the idle air regulator

The problem with floating speed occurs when the injection regulator is faulty. This automatic unit is made on the basis of an electromagnet with a needle and a conical tip. The regulator equalizes engine speed without load and with the gas pedal depressed. Most often, the causes of malfunctions are physical wear of the needle and tip, drive failure, as well as failure of the analyzer, on which deposits from low-quality gasoline appear.

You may also be interested in: Toyota RAV 4 Used: how to find a car in good condition

Diagnostics of the idle air regulator is performed on a computer, which allows you to determine the nature of the breakdown. The car owner can act by elimination by purchasing a new unit and replacing the old one, which, with a high degree of probability, will be worn out and broken after 150,000 kilometers. The cost of such regulator modules is not too high, which makes it possible to completely restore the performance of a car engine at minimal cost.

Possible causes of malfunction

Floating engine speed at idle is almost always caused by a violation of the composition of the fuel mixture or excessive air intake into the engine. The complexity of this problem lies in the fact that a wide range of malfunctions in the fuel supply system can lead to this.

In carburetor cars

Most problems with floating engine speeds with carburetor injection of the fuel mixture are directly related to the device itself (carburetor). As a rule, jumps in engine speed are associated with depletion of the incoming fuel mixture, caused by:

• incorrect adjustment of the idle speed by “craftsmen” or its failure as a result of operation;
• contamination of jets, fuel and idle air channels;
• breakdown of the solenoid valve of the device;
• sucking in excess air and subsequent depletion of the fuel mixture;
• incorrect fuel level in the carburetor float chamber (high or low);
• breakdown of the throttle valve or oil deposits that prevent the valve from opening and closing correctly;

As a result of these malfunctions in the fuel supply system, the engine begins to stall at idle.

In injection cars

In cars with forced fuel supply, most causes of engine stalling are often associated with electronic malfunctions. The operation of the electronic control unit (ECU), responsible for fuel injection, is based on the data received, which is transmitted by sensors. Jumps in engine speed occur due to the fact that, due to incorrect data transmitted by the mass air flow sensor (MAF), more air enters the injection valves than necessary. Due to excess air in the engine cylinders, the ECU “gives” a command to the injector valves to open slightly to supply fuel. As a result of its combustion, a jump in engine speed occurs. After the fuel burns, the engine speed drops again.

Also, the reasons for speed jumps on injection models can be:

• worn and clogged spark plugs;
• damage to high-voltage wires, causing incorrect operation of all car electronics;
• breakdown of the idle air regulator (IAC);
• malfunction of the EGR exhaust gas recirculation system;
• The oil pan ventilation valve is clogged.

In diesel cars

In cars with a diesel engine, the reasons for jumps in engine speed can be the same as in a gasoline unit. However, another reason may be the failure of the high pressure fuel pump (HPF). Corrosion or mechanical damage to the moving fuel injection pump blades leads to floating engine speeds, both at idle and while driving at low engine speeds.

Instability of idle speed with HBO

In a car running on gas, the engine speed jumps at idle for two reasons:

• a lean mixture contributes to poor combustion;
• spark problems.

In the second option, the culprit is the switch. And you will have to tinker with impoverishment. If checking the condition of the spark plugs and explosive wiring does not produce results, problems with this equipment can be eliminated by significantly reducing the search area and concentrating on the gas equipment. Alternately pinching the hoses leading to the insertion from the injectors will help detect the malfunction.

How to stabilize floating speed

1. Penetration of foreign air into the engine . It is necessary to check the tightness of the air system channels with the intake manifold. For such purposes, it is necessary to dismantle each hose separately and pump it with a pump or compressor, but you can try spraying liquid -40 on the hoses, where it will quickly evaporate; there is most likely a crack in the hose. In such a situation, it is better to replace the damaged hose with a new one rather than wrap it with electrical tape.
2. Replacing the IAC . The condition of this device is checked with a conventional multimeter, which needs to check its resistance. If the resistance readings are in the range of 40-80 Ohms, the regulator is faulty and such a device requires immediate replacement.
3. Cleaning the valve and elements of the engine ventilation system . In this case, you will have to disassemble the oil sump and get to the ventilation valve. It should be pulled out and washed in a product for cleaning engine elements from an oil film. You can use regular kerosene. Next, dry the valve thoroughly and then put it in its place.
4. Replacing the air flow sensor . This is the most delicate part and most often cannot be repaired. Therefore, if the cause is the air flow sensor, then it is advisable to replace it. It is known from practice that even professionals cannot repair a hot-wire anemometer.
5. Flushing the throttle valve and then installing it in the correct position . There are two methods for cleaning the throttle valve from oil contaminants: without removing it from the car, and also with removing the throttle valve. When removing the damper from the car, you must disconnect all wires and hoses from the damper, loosen it and pull it out. Next, place it in a container and fill it with cleaning aerosol. If the oil stains on the surface of the throttle valve are already old, you can clean them with a brush. Next, dry the damper surfaces with a rag and put them in place, connecting all the wires and hoses. If the damper is not removed from the car, then it can be washed on a hot power unit with a similar aerosol. Before spraying cleaning agent, disconnect power from the throttle valve. First you need to pour the product inside the throttle valve, wait a few minutes and start the engine. With the power unit operating, continue cleaning the damper with the same product. If, during such cleaning, white smoke comes from the damper, then this is normal, since oil contaminants are cleaned in this way. At the end of the work, you should connect the wires and adjust the operating order of the throttle valve on the computer, setting the required opening gap.
6. Idle speed adjustment . This procedure can be carried out using a regular screwdriver, adjusting the screws for the quality of the fuel mixture and the number of engine revolutions.
7. Replacing the solenoid valve . If the carburetor idle valve malfunctions, the engine can only operate when the choke handle is pulled out. Therefore, in order to prevent idle speed fluctuations, it is advisable to replace the valve with a known good one or a new one.
8. Cleaning the idle air jet . Even in the old days, cleaning the jet from oil deposits was considered a very labor-intensive task. Currently there is no need to remove the jet from the carburetor. To do this, you just need to pour a specialized product into it, designed for cleaning carburetors, and wait in this state for several minutes. Then you need to clean the nozzle from dirt using compressed air.
9. Treatment of parts of the fuel pump on a diesel engine from rust . To perform this task, you will need a specialized corrosion cleaning agent. This can be either an imported or a domestic product. It is simply sprayed into the fuel tank by opening its neck before refueling with diesel fuel at a gas station. The cleaning agent will clean the pump parts from rust on its own. In order to prevent similar corrosion of the high-pressure pump in the future, it is recommended to pour a glass of motor oil into the tank, which can form a protective film on the surface of the pump parts when moving.

We recommend: Renault Duster: manual transmission oil change

You need to know that if uneven engine speed occurs at idle, you must immediately contact a service station and carry out detailed diagnostics of the operation of all engine systems. Timely detection of faults will protect you from costly repairs.

Other faults

A failed engine control unit or observed wear of the cylinder-piston group as a whole will not be easy to identify on your own without the help of a specialist.

It should be borne in mind that the symptoms of many problems that lead to floating speed are similar in nature and manifestations. Carrying out independent work may lead to the replacement of fully serviceable spare parts or their breakdown.

To get a sufficient understanding of the nature of the current vehicle problems related to the dynamics of the internal combustion engine speed at idle or when the car warms up, you will need to visit a car service center. At the auto service and repair center, a comprehensive diagnosis of the engine unit can be carried out and problems with its operation can be identified. The conclusion of the diagnostic center allows owners to get a complete picture of the presence of faulty components and the degree of wear of serviceable ones.

Uremont.com, an aggregator of car services with the ability to select a contractor from a list, if the prices for the service are optimal, will help you carry out the entire list of work required for the engine inexpensively.

Stabilizing engine idle speed

Adjustment and stabilization of engine idle speed is carried out in the following ways:

1. Clean the valve from deposits (on the oil sump). It will be necessary to dismantle the crankcase and subsequent flushing with cleaning agents to remove oil deposits, dust and mechanical accumulations of sludge. The parts are cleaned, washed in kerosene and dried. Install the valve and assemble the system.
2. Crankcase gas ventilation (CVG). When fuel and oil burn, gas pressure is created in the engine, which is cyclically released by valves through pipes of complex geometry. Maintenance and cleaning of the VKG system will normalize speed, reduce fuel consumption and eliminate excessive oil consumption.
3. It is important to check the air supply lines. You will have to check the cylinders for leaks, blow out the hoses with a compressor and inspect the manifold. Air leaks can occur through cracks, which can be identified by treating the pipelines with WD-40. After the liquid evaporates, visually visible etching areas remain. Damaged hoses cannot be sealed (only replaced with new ones).
4. The throttle valve is flushed to remove oil-type deposits. After dismantling, the position can be reconfigured. The hoses are removed, the mounting bolts are unscrewed, and the damper is inspected for wear, sprayed with an aerosol and the deposits are cleaned off with a brush. After washing the planes, adjust the position (working clearances) of the damper and assemble the system.
5. Air flow is controlled by mass air flow sensors. The operating principle is based on reading the readings of a hot-wire anemometer. Mass flow sensors cannot be repaired (replacement only).
6. Jumps in idle speed are observed when the solenoid valve in the carburetor fuel supply system breaks down. A complete replacement is being carried out. You can get to the nearest service station using an extended choke flap.
7. The XX jets in the carburetor are cleaned with special means (aerosols) without removing them from the structure. After treating the nozzle with the additive, blow the channels with a compressor to remove any remaining mechanical particles.
8. You can clean traces of corrosion on the fuel injection pump blades with XADO VeryLube or with a product from another manufacturer. The composition is sprayed into the neck of an empty fuel tank (before full refueling). The substance settles and reacts on the pump blades, and a chemical process of corrosion neutralization occurs. In private practice, the “motor oil addition method” is used - about 150 ml is added to the tank with diesel fuel. The metal surfaces of the blades will be covered with a protective film, protecting them from the appearance of premature corrosion stains.

Problems with the injection engine

It is the cars where the injector is installed that are most often susceptible to this disease: jumps in idle speed. The reasons for such strange behavior can be different, but the most common are:

1. Air masses entering the cylinders in large quantities.
2. Failure of the idle speed controller.
3. Problems with the oil pan ventilation valve.
4. The cause may be a malfunction related to the crankcase mass air flow sensor.
5. The throttle valve often gets stuck. Its progress becomes unregulated.