throttle valve failure

throttle valve failure outwardly, it can be determined by such signs of the operation of the internal combustion engine - problems with starting, a decrease in power, deterioration in dynamic characteristics, unstable idling, an increase in fuel consumption. The causes of malfunctions may be damper contamination, the occurrence of air leakage in the system, incorrect operation of the throttle position sensor, and others. usually, damper repair is simple, and even a novice motorist can do it. To do this, it is cleaned, the TPS is replaced, or the suction of external air is eliminated.

Signs of a Broken Throttle

The throttle assembly regulates the air supply to the intake manifold, due to which a combustible-air mixture is subsequently formed with optimal parameters for the internal combustion engine. Accordingly, with a faulty throttle valve, the technology for creating this mixture changes, which negatively affects the behavior of the car. Namely, signs of a broken throttle position are:

• problematic start of the internal combustion engine, especially “cold”, that is, on a cold engine, as well as its unstable operation;
• the value of the engine speed is constantly fluctuating, and in a variety of modes - at idle, under load, in the middle range of values;
• loss of dynamic characteristics of the car, poor acceleration, loss of power when driving uphill and / or with a load;
• "Dips" when pressing the accelerator pedal, periodic power loss;
• increased fuel consumption;
• "garland" on the dashboard, that is, the Check Engine control lamp either lights up or goes out, and this repeats periodically;
• the motor suddenly stalls, after restarting it works normally, but the situation soon repeats itself;
• frequent occurrence of detonation of the internal combustion engine;
• in the exhaust system, a specific gasoline smell appears, associated with incomplete combustion of fuel;
• in some cases, self-ignition of the combustible-air mixture occurs;
• In the intake manifold and / or in the muffler, soft pops are sometimes heard.

It is worth adding here that many of the listed symptoms may indicate problems with other elements of the internal combustion engine. Therefore, in parallel with checking the breakdown of an electronic or mechanical throttle, additional diagnostics of other parts must be carried out. And preferably with the help of an electronic scanner, which will help determine the throttle error.

Causes of broken throttle

There are a number of typical reasons that lead to malfunctions of the throttle assembly and the problems described above. Let's list in order what kind of throttle valve failures can be.

Idle speed regulator

The idle speed controller (or IAC for short) is designed to supply air to the intake manifold of the internal combustion engine when it is idling, that is, when the throttle is closed. With a partial or complete failure of the regulator, unstable operation of the internal combustion engine at idle will be observed up to its complete stop. Since it works in tandem with the throttle assembly.

throttle sensor failure

also one common cause of throttle failure is problems with the throttle position sensor (TPSD). The function of the sensor is to fix the position of the throttle in its seat and transmit the corresponding information to the ECU. The control unit, in turn, selects a specific mode of operation, the amount of air supplied, fuel and corrects the ignition timing.

If the throttle position sensor breaks down, this node transmits incorrect information to the computer, or does not transmit it at all. Accordingly, the electronic unit, based on incorrect information, selects incorrect modes of operation of the internal combustion engine, or puts it into operation in emergency mode. Usually, when the sensor fails, the Check Engine warning light on the dashboard lights up.

Throttle actuator

There are two types of throttle actuator - mechanical (using a cable) and electronic (based on information from the sensor). The mechanical drive was installed on older cars, and is now becoming less common. Its operation is based on the use of a steel cable connecting the accelerator pedal and the lever on the throttle axis of rotation. The cable can stretch or break, although this is quite rare.

Widely used in modern cars electronic drive throttle control. Throttle position commands are received by the electronic control unit based on the information received from the damper actuator sensor and DPZD. If one or the other sensor fails, the control unit forcibly switches to emergency operation. At the same time, the damper drive is turned off, an error is generated in the computer memory, and the Check Engine warning lamp lights up on the dashboard. In the behavior of the car, the problems described above appear:

• the car reacts poorly to pressing the accelerator pedal (or does not react at all);
• engine speed does not rise above 1500 rpm;
• the dynamic characteristics of the car are reduced;
• unstable idle speed, up to a complete stop of the engine.

In rare cases, the electric motor of the damper drive fails. In this case, the damper is located in one position, which fixes the control unit, putting the machine into emergency mode.

Depressurization of the system

Often the cause of the unstable operation of the internal combustion engine of a car is depressurization in the intake tract. namely, air can be sucked in in the following places:

• places where the damper is pressed against the body, as well as its axis;
• cold start jet;
• connecting corrugated tube behind the throttle position sensor;
• joint (inlet) of the pipe of the crankcase gas cleaner and corrugations;
• nozzle seals;
• conclusions for petrol vapors;
• vacuum brake booster tube;
• throttle body seals.

Air leakage leads to incorrect formation of a combustible-air mixture and the appearance of errors in the operation of the intake tract. In addition, the air leaking in this way is not cleaned in the air filter, so it may contain a lot of dust or other harmful small elements.

damper contamination

The throttle body in the internal combustion engine of a car is directly connected to the crankcase ventilation system. For this reason, tar and oil deposits and other debris accumulate over time on its body and axle. typical signs of throttle valve contamination appear. This is expressed in the fact that the damper does not move smoothly, often it sticks and wedges. As a result, the internal combustion engine is unstable, and corresponding errors are generated in the electronic control unit.

in order to get rid of such troubles, you need to regularly check the condition of the throttle, and if necessary, clean it with special tools, for example, carburetor cleaners or their analogues.

How to clean the throttle valve

Before cleaning the throttle valve, it is worth studying five basic mistakes that car owners make in this procedure. Recommendations on how to properly clean carbon deposits from the internal protection. More details

 

Throttle adaptation failed

In rare cases, it is possible to reset the throttle adaptation. It can also lead to the mentioned problems. The reasons for the failed adaptation may be:

• disconnection and further connection of the battery on the car;
• dismantling (shutdown) and subsequent installation (connection) of the electronic control unit;
• the throttle valve has been dismantled, for example, for cleaning;
• The accelerator pedal has been removed and reinstalled.

Also, the reason for the adaptation that has flown off may be moisture that has got into the chip, a break or damage to the signal and / or power wire. You need to understand that there is an electronic potentiometer inside the throttle valve. Inside it are tracks with graphite coating. Over time, during the operation of the unit, they wear out and can wear out to such an extent that they will not transmit correct information about the position of the damper.

Throttle valve repair

Repair measures for the throttle assembly depend on the reasons for which the problems arose. Most often, the scope of repair work consists of all or part of the following measures:

• in case of complete or partial failure of the throttle sensors, they must be replaced, since they are not repairable;
• cleaning and flushing the idle speed controller, as well as the throttle valve from oil and tar deposits;
• restoration of tightness by eliminating air leakage (usually the corresponding gaskets and / or connecting corrugated tube are replaced).

Please note that often after repair work, especially after cleaning the throttle, it is necessary to adapt it. This is done using a computer and a special program.

Adaptation of the throttle valve "Vasya diagnostician"

On cars of the VAG group, the damper adaptation process can be done using the popular Vag-Com or Vasya Diagnostic program. However, before proceeding to adaptation, the following preliminary steps must be taken:

• pre-delete (preferably several times) all errors from the ECU on the internal combustion engine BEFORE starting the basic settings in the Vasya Diagnostic program;
• the voltage of the car battery must not be less than 11,5 volts;
• the throttle should be in the idle position, that is, it does not need to be pressed with your foot;
• the throttle must be pre-cleaned (using cleaning agents);
• the coolant temperature must be at least 80 degrees Celsius (in some cases it can be less, but not much).

The adaptation process itself is performed according to the following algorithm:

• Connect the computer with the installed program "Vasya diagnostician" using the appropriate cable to the service connector of the vehicle's electronic unit.
• Turn on the car's ignition.
• Enter the program in section 1 "ICE", then 8 "Basic settings", select channel 060, select and click the "Start adaptation" button.

As a result of the described actions, two options are possible - the adaptation process will start, as a result of which the corresponding message "Adaptation OK" will be displayed. After that, you need to go to the error block and, if there are any, programmatically delete information about them.

But if, as a result of launching adaptation, the program displays an error message, then you need to act according to the following algorithm:

• Exit the "Basic settings" and go to the block of errors in the program. Remove errors twice in a row, even if there are none.
• Turn off the car ignition and remove the key from the lock.
• Wait 5 ... 10 seconds, then insert the key into the lock again and turn on the ignition.
• Repeat the adaptation steps above.

If, after the described actions, the program displays an error message, then this indicates a breakdown of the nodes involved in the work. namely, the throttle itself or its individual elements may be faulty, problems with the connected cable, an unsuitable program for adaptation (you can often find hacked versions of Vasya that do not work correctly).

If you need to train the Nissan throttle, then there is a slightly different adaptation algorithm that does not require the use of any program. Accordingly, on other cars, such as Opel, Subaru, Renault, their principles of learning the throttle.

In some cases, after cleaning the throttle valve, fuel consumption may increase, and the operation of the internal combustion engine at idle will be accompanied by a change in them. This is due to the fact that the electronic control unit will continue to give commands in accordance with the parameters that were before cleaning the throttle. In order to avoid such a situation, you need to calibrate the damper. It is done using a special device with resetting past operating parameters.

Mechanical adaptation

With the help of the specified Vag-Com program, only cars manufactured by the German concern VAG can be programmatically adapted. For other machines, their own algorithms for performing throttle adaptation are provided. Consider an example of adaptation on the popular Chevrolet Lacetti. So, the adaptation algorithm will be as follows:

• turn on the ignition for 5 seconds;
• turn off the ignition for 10 seconds;
• turn on the ignition for 5 seconds;
• start the internal combustion engine in neutral (manual transmission) or Park (automatic transmission);
• warm up to 85 degrees Celsius (without revving);
• turn on the air conditioner for 10 seconds (if available);
• turn off the air conditioner for 10 seconds (if any);
• for automatic transmission: apply the parking brake, depress the brake pedal and shift the automatic transmission to position D (drive);
• turn on the air conditioner for 10 seconds (if available);
• turn off the air conditioner for 10 seconds (if any);
• turn off the ignition.

On other machines, the manipulations will have a similar character and do not take much time and effort.

Running a faulty throttle valve on an internal combustion engine has sad consequences in the long run. namely, while the internal combustion engine does not work in the optimal mode, the gearbox suffers, elements of the cylinder-piston group.

How to determine air leakage

Depressurization of the system, that is, the occurrence of air leakage, can lead to incorrect operation of the internal combustion engine. In order to find the places of the indicated suction, you need to perform the following actions:

• By means of diesel fuel spill the installation sites of the nozzles.
• With the engine running, disconnect the mass air flow sensor (MAF) from the air filter housing and cover it with your hand or other object. After that, the corrugation should shrink a little in volume. If there is no suction, then the internal combustion engine will begin to "sneeze" and eventually stall. If this does not happen, there is an air leak in the system, and additional diagnostics are needed.
• You can try closing the throttle by hand. If there is no suction, the internal combustion engine will begin to choke and stall. If it continues to work normally, there is an air leak.

Some car owners pump excess air pressure into the intake tract with a value of up to 1,5 atmospheres. further, with the help of a soapy solution, you can find the places of depressurization of the system.

Prevention of use

By itself, the throttle valve is designed for the entire life of the car, that is, it does not have a replacement frequency. Therefore, its replacement is performed when the unit fails due to mechanical failure, failure of the entire internal combustion engine, or for other critical reasons. More often than not, the throttle position sensor mentioned above fails. Accordingly, it must be replaced.

For normal operation of the internal combustion engine, the throttle valve must be periodically cleaned and reconfigured. this can be done either when the above signs of breakdown appear, or simply periodically so as not to bring it to such a state. Depending on the quality of the fuel used and the operating conditions of the car, it is recommended to clean the throttle during the engine oil change process, that is, every 15 ... 20 thousand kilometers.