Why does the car stall on the run, then start? Reasons, troubleshooting

It happens that motorists are faced with a problem when the engine of their car without any cause stalls right while driving. The reason for this phenomenon can be several factors. In order to further minimize the risk of being in this situation, this article details the main problems of the motor systems and how to eliminate them.

Engine stalls: causes

As already noted, there can be more than enough of them. If we consider in order, we can define several of the most common.

• Low quality fuel or its complete absence. As a rule, if earlier problems with the motor did not happen, drivers first of all think about fuel. In the event that there is fuel in the tank, it is necessary to solve this problem as follows: replace the fuel and the fuel filter.
• Poor-quality or exhausted spark plugs. In this case, the machine jerks and stalls on the move, the engine detonates and starts badly. The problem is eliminated by checking the candles and, if necessary, by completely replacing them.
• Fuel filter status. If it has not changed for a long time or when using low-quality fuel it is strongly clogged and has a low throughput. This can cause interruptions in the fuel supply and help stop the engine. This fault is eliminated by replacing the filter element.
• Air filter. Clogging it leads to insufficient air supply to form a quality fuel-air mixture. Without the optimum amount of oxygen, the combustion of the fuel in the cylinders deteriorates, and the engine simply "chokes". As a rule, with this kind of malfunction the engine stalls mostly at idle. Therefore, it is necessary to replace the air filter - and the cause will be eliminated.
• Do not pump the gasoline pump. If this happens, the liquid from the tank does not flow to the engine. It happens that the pump works with intermittent outages, which is why the machine starts, and then stalls either immediately or after a while. When the pump does not pump at all - the engine can not be started. In the event that the cause lies in the pump, it must be repaired or replaced with a new one.
• Accumulator battery. The presence of clogging and oxidation of the output terminals of the battery can also be the reason why the machine stalls on the go. Interruptions in the power system in the engine system can cause it to stop. It is important to keep the battery terminals clean.
• Malfunction of the generator. If the generator of the car fails, all electronic systems start to eat exclusively from the battery, which leads to its rapid discharge. As a result, the machine stalls on the go, then it starts after a certain time, when the battery partially restores its charge. Typically, this can be repeated several times until the battery life is fully exhausted. With such a breakdown, the generator must be diagnosed and repaired.
• The failure of additional sensors to monitor and control the engine systems. In the event that the above-mentioned parts and systems are not relevant to the performance of the motor, the cause of the failure can serve as a different sensor. Basically, they are installed on more modern cars. If you determine what exactly is a malfunction or malfunction, it is not possible at home, you need to use the services of a specialist.

The engine stalls when going to neutral

The reasons that the engine stalls at idle speed can be identical to that of the car. But there are inherent in the work of the motor idle.

A common problem is a malfunction of the idle speed sensor, which is directly related to the action of the power unit in this mode. You can check the status of the sensor yourself as follows. If the engine does not start at the moment of starting, you need to swing the gas pedal several times. When the unit starts, remove the foot from the pedal and check the engine speed. If they are unstable and chaotic "swim", the probability that the problem lies precisely in the sensor is very large. This type of fault is solved by flushing the sensor with a conventional WD-40 or installing a new one.

For the second reason, we can include the clogging of the throttle, which simply needs to be washed.

Particular attention should be paid to the throttle position sensor. This can also contribute to the fact that the car stalls on the go, then gets wound up.

To eliminate this breakdown is quite simple, it is enough to replace the sensor, which can be done independently.

Weather

The reasons for the unstable operation of the engine at idle speed also include weather conditions. Very often the power unit stalls when trying to warm up the machine in the frost, which greatly complicates the implementation of this process.

So, for example, a car on gas stalls at idle due to the freezing of gas in the reducer. This happens if the engine is not heated on gasoline, but immediately on gas. The gas reducer is heated and connected to the cooling system. Since the unit itself is still cold, and the gas entering the reducer has the property of cooling when pressure changes, icing and plugging of the gas pipeline elements and gearbox parts takes place. It is this factor that does not allow the engine to operate at idle speed steadily and without stopping.

To prevent frost and trouble-free heating, the engine must be heated on gasoline before raising the temperature of the coolant. Folk craftsmen have adapted before starting the engine to warm up the gas reducer with hot water from the kettle. This prevents premature freezing of the elements of the gas equipment until the engine has warmed up.

Problems in car carburetor

Sometimes, the engine is easily started and for some time it works stably on all modes, but after a certain time stalls. Incorrectly adjusted carburettor flap drive leads to an excessive increase in the amount of fuel supplied. Therefore, the machine stalls on the run, then gets wound. The carburetor feeds into the combustion chamber a too enriched mixture that does not ignite.

Exceeding the level of fuel in the carburetor float chamber can also affect the operation of the motor. In general, this is a misalignment of the fuel supply level, clogging of the needle valve or its wear. When repairing the carburetor, it is not recommended to replace only its individual components, but to completely install a new repair kit and then adjust the carburetor.

There is another reason why the car stalls on the go (VAZ including) is the state of the carburetor solenoid valve. Check its suitability is quite simple: you need to turn on the ignition, then remove the terminal from the valve and connect it back. If the valve is OK, a characteristic click in the valve body will be heard when the terminal is connected. When the click does not follow, try installing another valve on the carburettor.

Injection motor

If the machine stalls at idling speed, the injector can also be a cause of breakdown. Often this contributes to the disruption of the normal fuel mixture, the violation of the vacuum and suction of air in the intake manifold after the air intake sensor.

Changing the optimal throttle position and malfunction of the oxygen sensor. Clogging fuel injectors and insufficient fuel pressure, as well as malfunctioning the fuel pump, clogging the fuel filter, a broken pressure regulator can affect the fact that the car stalls on the go. The reasons can be hidden in the engine cooling system, more precisely, in the thermostat. If it is defective, the engine may not warm up sufficiently to the operating temperature. However, this applies to all engines. A failed coolant temperature sensor may incorrectly inform the on-board computer of the coolant temperature state and at the same time disrupt the normal operation of the power unit.

System management block

There is a possibility that the motor stops due to malfunctions in the electronic control unit. Incorrect installation of the program or its failure during operation leads to malfunctions in various engine control systems. At the same time, the problem can occur with a certain periodicity or with a change in operating conditions during driving. That's why the car stalls on the go, even with a working mechanic.

Catalyst

A clogged and faulty catalyst can also affect the operation of the motor. Determine if the catalyst is clogged or not, it's pretty simple. To do this, you need to warm up the engine well, preferably at higher revs. Then, from the inspection ditch, inspect the device without using additional lighting - if it is lit, this means that it has a contamination and poorly passes the exhaust gases.

When the car stalls on the run, then it starts ("Priora", for example) - malfunctions can hide in the exhaust gas recirculation valve (error P1406). In the event that the exhaust valve jams in the slightly open position, the engine will not develop full power, but at low speeds it can stall. When, on the contrary, it is closed all the time, then at high speeds the motor will run unsteadily and detonate.

Absolute pressure sensor

Its malfunction can give to the computer indicators that do not correspond to the mode of the engine. The pressure sensor measures the vacuum in the manifold used by the control unit to determine the load characteristics for the power plant, and only then the computer regulates the optimum mixture formation. And when the machine stalls on the move, the reasons may lie in the insufficient or excessive amount of fuel mixture necessary for normal operation during various loads and regimes.

The engine stalls periodically

This phenomenon may be due to malfunctions in the ignition system. During the movement, chaotic interruptions can occur with sparking on spark plugs, while at the same time it is at some definite and all at the same time. Absence of a spark with a high probability will lead to a stop of the unit.

If the car is stalled on the go, then it is started (2112th VAZ including), then the most common reasons include the following: malfunction and presence of moisture in the ignition coil, damage to the crankshaft position sensor and ignition module, failure of safety elements of control systems Sensors. In this case, it is necessary to pay attention to the condition of electric wires and their connections, which can contribute to power outages.

Very rarely the machine stalls on the run, then it is started because of a faulty vehicle speed sensor.

Optional equipment

Typically, the stable speed of the motor of most cars is affected by the inclusion of an air conditioning compressor. Very often this happens at low and idle. Since the air conditioner consumes a considerable amount of energy, the control unit gives the signal to the power system to increase the volume of the fuel mixture supply to increase the idling speed to compensate for the power loss consumed by the air conditioner.

But when the impulse to turn on the air conditioner does not enter the electronic unit due to the communication failure between the computer and the device module, the control unit is not able to assess the situation and add fuel. As a result of this, the stability of the idling turns is violated until the moment when the engine is completely deaf.

Troubleshooting

Determine the reasons why the machine stalls at idling speed, then gets wound up, it needs to be phased in, considering the possibility of damage and malfunctions in certain systems and components of the car. It is much easier to do this if the problem is obvious or already familiar.

It is important to use the hints that the onboard computer can give in the form of error codes in the operation of certain systems. When the problem is insignificant and lies in the mechanical part, it can be eliminated at home by replacing unsuitable elements. At the moment when faults occur precisely with respect to electronics and can not be repaired independently, it is necessary to carry out diagnostics on special stands at the auto-service stations.