A situation where the car suddenly loses traction and the engine stops working right while driving can scare even an experienced driver. It is especially alarming if after a few minutes the car starts again and behaves as if nothing has happened. This behavior of the vehicle indicates a latent malfunction that can occur periodically, but it is dangerous to ignore it.
Reasons why engine stallsThere can be many: from banal poor-quality fuel to serious failures in electronics. Most often, the problem lies in the violation of fuel supply, spark formation or failures in the operation of engine control systems. Understanding the nature of these failures will help you find a solution faster and avoid costly repairs.
In this article, we will discuss in detail the main components responsible for the stable operation of the engine, and explain why the car can stall and then start again for no apparent reason. You will learn which symptoms to pay attention to first and how to conduct a primary diagnosis yourself.
Problems with the fuel system
One of the most common reasons for stopping the engine is a violation of the fuel supply. If gasoline or diesel stops flowing into the cylinders, combustion of the mixture becomes impossible, and the engine dies. This often happens due to clogging. fuel-filterIt accumulates dirt and rust from the tank over time.
Another critical element is the fuel pump. It can overheat or have worn brushes, which periodically stops pumping fuel under the desired pressure. After cooling down or a light impact on the tank, the pump can start again and the machine will drive on. It's worth checking out. fuel pressureIt can release pressure in the ramp at the wrong time.
How to check the pressure in the fuel ramp?
A manometer is needed for accurate diagnosis. Connect it to the fuel ramp connection (on injection cars) and measure the pressure when ignition is turned on and at idle speeds. Normal values are usually 2.5-3.5 atmospheres, but the exact figures depend on the model of the car.
Do not forget about the quality of the fuel. Water trapped in the tank or excessive amounts of impurities can cause the motor to stop temporarily, especially when the engine accelerates or climbs uphill when the fuel intake is exposed or captures sediment from the bottom of the tank.
- ⛽ Clogging of the fine cleaning fuel filter.
- 🔇 Failure or overheating of the gas pump.
- 📉 Failure of the fuel pressure regulator.
- 💧 Getting water or dirt into the fuel tank.
Ignition system malfunction
To ignite the fuel-air mixture, a powerful and timely spark is needed. If the ignition system fails, the engine will stop instantly. Often the culprit is the spark-plugwhich may be filled with fuel or have too large a gap between the electrodes.
High-voltage wires and ignition coils are also subject to wear. When heated, microcracks may occur in them, through which a breakdown of current per mass occurs. As a result, the spark disappears and the car stops. After cooling, the insulating properties are restored, and the car starts again.
Special attention should be given crankshaft (DPCV). This is one of the main elements of engine control. If it overheats or its wiring is damaged, the signal about the position of the pistons disappears, and the ECU ceases to give a command to spark.
Check the condition of the candles: twist them out and examine the color of the soda. Black nagar speaks of a rich mixture, white - of a poor one, and oily plaque indicates problems with the piston group or oil caps.
In modern electronic ignition cars, problems can also occur in the ignition control module. Overheating of this unit leads to its temporary shutdown, which causes the engine to stop until the unit completely cools down.
Failures in the operation of sensors and electronics
The modern car is a complex computer controlled by electronics. If electronic control The ECU receives incorrect data from sensors, it may decide to stop the engine for protection or simply lose control of the combustion process.
Critically important is air-flower (DMRV). It measures the amount of air entering the engine. When it malfunctions, the mixture becomes either too rich or too poor, leading to unstable operation and stalled motor. Similar symptoms are associated with and throttle-proof.
Wiring problems are often masked as sensor failures. Oxidized contacts, rubbed wires, or poor “mass” can cause periodic signal loss. This is especially true after washing the engine or driving through puddles, when moisture enters the connectors.
⚠️ Warning: If the indicator on the dashboard is lit
Check EngineDon't ignore it. Count the error code through the OBD-II diagnostic connector – this will significantly narrow the search for a malfunction.
Air system and suctions
The internal combustion engine needs not only gasoline and spark to work, but also the right amount of air. Violation of the leakproofness of the intake tract, known as air-suckerThis leads to the impoverishment of the mixture. The engine begins to work unstablely and may stall, especially at idle speeds.
Often the culprit becomes the culprit. idler (RXX). If its rod jams or contaminates the channel, the car will stall when gas is discharged or gear shifts are switched. Cleaning this node often solves the problem.
It is also worth checking the condition. throttle. The coar on its edges can interfere with a tight closure or, conversely, make it difficult to open. In modern electronic throttle control (E-Gas) systems, problems can be software-based or related to wear and tear of the throttle itself.
☑️ Air system inspection
Scored air-filter Another common but common reason. If the engine lacks air, it begins to “choke” and deafens under load. Replacing the filter is a simple procedure that can be done on your own.
Table: Main symptoms and probable causes
To systematize the search for malfunction, it is convenient to use the table of correspondence of symptoms and probable causes. This will help you to quickly navigate during the diagnosis.
| Symptoms. | Probable cause | System system |
|---|---|---|
| It's dead on singles, it starts right away. | RX, air suction, DMRV | Air/Fuel/Fuel |
| It is deaf when accelerated under load | Fuel pump, filter, coils | Fuel/Ignition |
| It is hot, and it starts after cooling. | Crankshaft sensor, ignition module | Electronics/Ignition |
| Deafness when braking | Idle control, vacuum | Airborne |
| Deaf and long spins starter | Benzonasos, pressure regulator | Fuel. |
The frequency of the problem (cold, hot, under load) is a key factor for the correct diagnosis.
Mechanical problems of the engine
Although less often, but the cause of the stop can be mechanical malfunctions. For example, lip-belt or chains. In this case, the car stalls abruptly and no longer starts, but sometimes the belt can slip, causing a temporary loss of gas distribution phases and engine stoppage.
Problems with crankcase (PCV) can also lead to unstable performance. If the valve jams, the pressure in the crankcase increases, which disrupts the operation of the engine. Oily soda can get into the intake manifold, disrupting the composition of the mixture.
Low oil levels or poor quality can trigger the oil pressure sensor (in some models, this blocks the engine) or lead to jamming of the nodes, which feels like a sudden stop.
⚠️ Warning: If you hear a metal thud or a loud noise before stopping, further engine start-up may lead to its major destruction. Call a tow truck.
Diagnostics and solutions
If the car stalls and starts, the first thing you need to do is to conduct a visual inspection. Check the integrity of the wires, the reliability of contacts on the battery and the condition of the connectors of the main sensors. Often the problem is solved by a simple cleansing.
Be sure to perform a computer diagnostic. Even if the light bulb Check Engine does not burn, in the memory of the ECU can be stored pending (waiting) error codes that indicate a faulty sensor. Use the scanner or contact the service.
Check the pressure in the fuel ramp and the pump performance. If the pressure drops immediately after the ignition is turned off, the return valve in the pump or pressure regulator may be faulty. This causes difficulties with starting "hot".
Method of exclusion
If you can not make a full diagnosis, try to replace the most likely and inexpensive elements (candles, filters) with the obviously serviceable. If the problem is not gone, look deeper.
When the car is stalled in motion, it is important to remain calm. Turn on the alarm, try to pull over to the side of the road using inertia. Don’t try to start your car at high speed – it can be dangerous. Stop first, then make a diagnosis.
Frequently Asked Questions (FAQ)
Why does the car stop on the move, but start immediately?
Most often, this indicates a short-term failure in the ignition system (for example, a failure of the coil during heating) or a temporary drop in pressure in the fuel system. It is also possible to suck air, which is compensated for when restarted.
Can the engine be shut down because of bad gasoline?
Yes, a low octane number or the presence of water in the fuel causes detonation and disruption of the combustion process, which leads to the engine stopping. After the production of low-quality fuel, the problem disappears.
What to do if the car is stuck in a rainstorm?
Moisture could get into the ignition system (tamper, high-voltage wires, candles). It is necessary to dry the elements of the ignition system, treat them with a spray to protect against moisture (WD-40 or analogue) and check the air filter for wetness.
How do I know if the gas pump is dead?
When you turn on the ignition, you should not hear the characteristic hum of the pump from the tank. Also a sign is a loss of power during acceleration and jerk before the full stop of the engine. The pressure in the ramp will be zero or very low.
Is it dangerous to drive if the car is dead?
Yeah, it's dangerous. Sudden loss of power can lead to accidents, especially when overtaking or crossing intersections. In addition, frequent launches and stops can damage the catalyst and starter.