Why does the engine stall at idle: causes and solutions

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Any self-respecting car owner should monitor the he alth of his car and keep it in good technical condition. But sometimes there are problems with the launch and operation of the power unit. For example, the engine stalls at idle. What is the reason for this phenomenon, how to deal with it? We will talk about all this in our today's article. Before answering the question of why the car stalls at idle, we note that all problems will relate to malfunctions with the supply of the fuel-air mixture.

If it's a carburetor?

On older cars with a carburetor intake system, with such symptoms, the automatic throttle fails. This element "sinks" or is poorly adjusted. If the VAZ-2106 stalls at idle, the malfunction may be accompanied by a leak from the vacuum hoses near the base of the carburetor. Do not rule out problems in the cooling system. If the car stalls at idle,check the condition of the thermostat. With a faulty valve, the mechanism does not allow the engine to quickly warm up to operating temperatures. In the summer, the machine often boils.

Intake system details

Because the engine needs oxygen as well as gasoline to run, the RPM problem is related to the air intake manifold. Such troubles occur due to air leakage in the place that comes after the filter. As a result, the air mass meter sensor is unable to control the process, and the machine stalls at idle.

The injector is often equipped with a MAF. You should not ignore him. Often this sensor gets dirty after 100-150 thousand kilometers. It cannot be repaired, only replaced. This part is inexpensive, but it is because of it that in most cases idle speeds float. The engine stalls also due to fuel injectors. It is worth checking the condition of the injector. If it is clogged, the crankshaft speed will be unstable. A different amount of combustible mixture enters the combustion chamber, which contributes to the incorrect operation of the internal combustion engine.

Filters

After a run of 10 thousand kilometers, it is necessary to change the air filter. It is located in a plastic or metal case (on injection and carburetor engines, respectively). If this item looks like the one in the photo below, it should be replaced.

But not only the air is cleaned in the system. Pay attention to fuel filters. On diesel engines, they change every 15 thousand kilometers. Concerningcars with gasoline engines, they are serviced every 50 thousand. The throughput of these elements is 10 microns. If low-quality gasoline or diesel was used, the inside of the filter quickly becomes clogged. Inside is porous paper.

When there is a lot of dirt, the element is no longer able to clean the fuel. As a result, the car does not keep idle, stalls. Even the fact that the pump operates under high pressure does not save. If the filter is very clogged, it must be changed immediately. A sign of replacement is also power loss and dips in dynamics.

The difference between carburetor and injection filters

It is worth noting that the pressure level in these intake systems is different. In injection engines, it is many times larger. Therefore, when buying new fuel filters, you should check with the seller which engine you have. This is especially true for cars on which different types of systems were installed (for example, old and new “tens”).

If you put a filter designed for a carburetor on an injection engine, it simply cannot withstand the pressure. All the dirt will get into the injector pump. They get clogged, so the engine stalls at idle. As for air filters, they are very easy to distinguish. For carbureted engines, they have a round shape.

Nuleviki

If a zero resistance filter is used in the car, if it is very dirty, it can cause problems in the engine. But the cost of such a cleaning element in7-10 times higher than ordinary ones. Therefore, special sprays are used to clean them. Filters are processed every 10 thousand kilometers. After applying the composition, wait until it is absorbed, and rinse the Nulevik with water for 5 minutes. Dry thoroughly before installation. Otherwise, the machine will seize the water hammer when starting.

Pumps

If the car stalls at idle, the cause may be low pump pressure. On injection engines, it is submersible and is located in the fuel tank itself. On carburetor engines, this element is located separately from the tank and belongs to the mechanical type. This pump is operated by a hand crank. It is she who creates the necessary pressure in the system. But if the fuel line is clogged, the submersible and mechanical pumps do not work at full capacity. As a result, the car stalls at idle.

If the car does not start at all, it is worth checking the power to the element. Look at fuses and relays. If the pump does not buzz on the injection motor when the ignition key is turned, then it is not receiving power. On passenger cars, it is located in the rear of the cabin, on the right (under the passenger sofa). If this is a diesel power unit, it is worth checking the high pressure fuel pump. At negative temperatures, paraffin accumulates in it - frozen particles of diesel fuel. There are problems with starting the engine, the speed often “floats”. Do not exclude mechanical failure. The cam drive may have failed.

Electronics

If the car stalls at idle, it is necessary to diagnose the on-board computer. In case of errors in programming, incorrect mixture formation occurs. Because of this, the motor starts to malfunction. This happens when you turn on additional electrical appliances (for example, air conditioning). The way out of this situation is to flash the electronic control unit.

Catalytic converters

With the increase in environmental standards, so-called particulate filters began to be installed on diesel cars, and catalysts on gasoline cars. They are designed for a certain period of operation (about 150 thousand kilometers). Over time, the core becomes clogged. The device cannot perform normal exhaust and exhaust gas purification.

The way out of this situation is to replace the catalyst with a flame arrester and flash the electronic unit. But at the same time, the emission standards of your car will fall to Euro-1 values. In the countries of the European Union, the operation of such vehicles is prohibited. But if you travel mainly in the CIS, this is the most optimal solution to the problem. After all, the cost of a new catalyst and a particulate filter starts at 40 thousand rubles.

Recirculation valve

The machine may stall at idle due to faults in the EGR system. During computer diagnostics, an error will be displayed on the screen"P1406". It indicates that the valve is "stuck" in the open or closed position. The car stalls at idle and exhibits weak dynamics at high. Over time, plaque accumulates on this valve. The element should be dismantled and cleaned. But if the symptoms recur during reinstallation, only a replacement will help.

Absolute pressure sensor

This mechanism measures the vacuum in the manifold to adjust the amount of mixture supplied. A defective element misleads the engine. The ECU thinks that the motor is running under much less or more load than it actually is. Thus, the control unit removes a certain amount of fuel. The car starts to stall. The way out is to replace the absolute pressure sensor. So, we found out for what reasons the car stalls at idle.