The engine is intermittent: possible causes and solutions

Every car enthusiast often encountered unstable engine performance. It manifests itself in floating speed, both under load and idling. The motor can work smoothly, and then there is a feeling that it is going to die out. However, it again starts to work stably. What is the reason? Let's try to figure out why the engine works with interruptions, and also learn how to solve this problem.

Cases of unstable operation of ICE and attempts to eliminate

During operation, the motor may be twitching. Sometimes it's just not possible to drive normally by car. Car maintenance specialists call different reasons. So, some say that in unstable work, the gasket under the cylinder head is guilty. But the subsequent replacement of it does not give anything. The second expert diagnoses that the fault is the valves. However, after adjusting the result, there is again no. The intake specialist insists that the carburetor / injector is no good and you need to buy a new one or clean it. But, naturally, the result is again unsatisfactory.

Whatever they do, and the engine works intermittently. And it turns out that in this case the problem was the connector of the trambler - in the chip, which is connected to the ignition distributor. Because of this, contact is broken. Apparently, not always unstable work is connected with carburettors, candles and other nodes. The electrical wiring is more often to blame. We will dwell on this in detail.

Causes of unstable work: ignition system

The first reason is defective candles. Even if one single candle does not work or it will work incorrectly, stable operation of the power unit will be impossible. At least one cylinder of the engine will work intermittently.

This motor operation is associated with a faulty ignition coil. This does not happen as often as various problems with candles. But the problem should not be ruled out. To understand that something is wrong with the coil, you can by spark. If its power has decreased noticeably, as a result, this leads to unstable and unstable operation of the ICE.

Many car enthusiasts will be very surprised, but often the engine does not work with interruptions at all because of the carburetor or injector - the cause is a battered or damaged high-voltage spark plug wire. As a result, this leads to a decrease in engine power, its unstable operation and other problems.

Again, return to the cover and contacts of the trambler as one of the reasons for the unstable operation of ICE. If the vehicle has a contact ignition system, the motor may not run smoothly if the contacts are damaged. You can forget about any stability "on the idle". Also, there are situations where the coal burns away, located in the center of the cap of the trambler on its inner side.

Power supply system and unstable engine operation

The reliability of the power supply system is a guarantee of smooth and stable operation of the motor. Consider the typical malfunctions, which are the cause of the unstable engine revolution.

If the engine is running with interruptions, the reasons can be in poor-quality gasoline. Today, at fuel stations, such fuel is sold very often. If you fill the car with substandard fuel, engine speed will float, and the car will twitch. Sometimes the car simply refuses to go. Specialists recommend in this situation to drain all fuel and check the fuel for the presence of water in it. If the gasoline is completely drained, the whole pipeline is pumped through the pump. Also, it will not be superfluous to flush the carburetor and replace the fuel filters.

A clogged fuel filter or carburetor is another possible reason. Garbage in the carburetor can cause the engine to fail to start. If the channels or jets are clogged, the combustible mixture can not fully enter the combustion chamber. This will immediately affect the work of ICE.

Interruptions in the engine and electrical equipment: signs, ways to eliminate

If the engine is running with interruptions and there is a feeling that the engine is stalling now, you need to pay attention to the tachometer. If, at the time of unstable operation, the needle twitches, the cause of the malfunction should be sought in the electrical equipment. These are symptoms of short-term failures in the ignition system (there is no spark). If the tachometer is not available, it is possible to determine the fault with the spark without it. The car jerks sharply when driving.

But it is not always possible to quickly find the reasons for the short-term loss of a spark. Often, as already noted above, these are bad contacts or an ignition coil. Another culprit is the condenser, contaminated contacts. If new contacts are installed, and the motor runs unevenly, then it means that they are bad.

Trembler and capacitor

If the problem in the capacitor on the switch (and it can both fail completely or partially), then the motor will start, it can regularly and stably operate at idle. But in the process of movement the unit will twitch. This indicates a spoiled condenser. Remove the lid from the trambler, feed the slider so that the contact opens. How is it checked? Hand twist the slider so that the contact is opened.

In the process of opening, a spark must skip. With a spoiled condenser, it will be blue and strong enough.

Also on the trampler may be an insufficient or too large gap in the contacts. This causes the motor to run erratically. The rod can swing from side to side. It has cams and a slider. Contacts will be opened without special clarity, which will cause interruptions. It is necessary to replace the stem bushings or the whole trampler completely.

High voltage wires

We have already considered this reason above. If the engine is running with interruptions (injector or carburetor, it does not matter), then the first thing to pay attention to the wire connections. If the plug is covered with a green coating, you need to drop on it with oil and then wait. The grease corrodes the oxides and removes them. Also, you can unscrew and tighten the nuts with which the wires are attached to the ignition coil.

If this does not help, then by replacement you can easily find the failed part. But the difficulty is that if the ignition coil is working partially, you can only detect this by replacing it with a new one.

Work with interruptions - this is not a trip

Do not confuse disruptions in the engine with a trip, when one of the cylinders does not work. When the motor "troits", there will be no twitching. In this case, there is a bad thrust. And at idle, twitching will still happen.

If the car VAZ-2107 engine is working intermittently, then the problem is definitely with the ignition system. If the engine stalls suddenly when the gas is pressed hard and then picks up and starts to gain momentum, the reason is in the carburetor. The ignition system has nothing to do with it. Rarely, dips can be associated with a faulty coil. The latter gives a weak spark.

Gasoline pump

It happens that the gasoline pump pumps fuel poorly, but there is no malfunction in the calm mode.

It is only necessary to push hard on the gas, the car will start to twitch, and there will be no strong jerks. The engine stalls and then picks up again. And if you reset the pedal and press again, the motor will again run smoothly. In this case, it is recommended to replace or repair the gasoline pump or its stem. Why does the engine run intermittently? He does not have enough gasoline because the fuel pump does not work effectively.

Idling and intermittent operation

This is also one of the most common problems that most car owners face. There are many reasons for this phenomenon. In this case, the malfunction depends on the type of motor - the carburetor is an aggregate or injector. Consider each species separately.

Carburetor cars

If the engine is running at idle speed, this may indicate that the XX setting in the carburetor is lost. It is shifted towards a poorer fuel mixture. In this case, it is recommended to adjust the idle speed to 800-900 rpm on the carburetor.

It is also possible the failure of the solenoid valve. In this case, the engine will operate normally only when the drain is fully extended. If you remove it, the engine immediately stalls.

Unstable operation of the engine is also associated with clogged carburetor jets or idling channels. There is not enough air in the fuel. This problem can quickly be solved by cleaning the carburettor in general and jets.

If there is a suction of excess air, then it also leads to the formation of a poor mixture. As a consequence, the engine is running at idle. Check the inlet connections for leaks.

Injection motor

Modern injector units are more technologically advanced, but they also have problems. Often the fault is due to the failure of any sensor. Also, there are problems with candles, air supply (here on the nozzle is a flowmeter DFMR). The latter can be sucked into the system "from the outside".

Also, you should not exclude problems with wires. Often, an open circuit sensor or an EGR valve breaks down.

Interruptions on the cold engine

Usually the car starts and immediately stalls. Then, the next time the key is turned, the engine is already running normally. In the first case, fuel leaves the fuel pump in the tank, and in the float chamber of the carburetor fuel is already there. When the key is turned on, the engine starts and runs normally, but the pump has not yet sat down to pump petrol into the carburettor. Because of this, the cold engine runs intermittently.

Also, the carburetor can prepare a too poor or re-enriched mixture. In the injector units, the cause in the nozzle, which "on the cold" gives not the portion of the mixture in any cylinder. The solution of the problem is cleaning at the stand.

Summarize. As you can see, the motor is unstable for different reasons. First of all, you need to pay attention to the intake and ignition system. Perhaps the problem is with any wiring or sensor.