Trouble injection engine: find the fault with your own hands

If the engine is unstable, this phenomenon is called “missing” abroad. To our ears the word is foreign and not understandable to everyone. Experienced mechanics know what this is. Missing is a misfire of the combustible mixture in one of the cylinders. More often than not, drivers in this case say that the engine is misfiring. In this article we will find out what causes the occurrence and what ways to eliminate the defect are possible.

Engine movement is accompanied by “swelling”. The sound is quite distinct and recognizable. This is what signals a bad cylinder. The engine temperature rises quickly. The compression ratio in the cylinders decreases (can be checked with a compression gauge). The power unit is subject to rapid wear. Therefore, it is important to determine why the engine is tripping and eliminate the malfunction as quickly as possible.

Not to be confused with detonation.

Reasons for tripling

Strong engine vibrations are the first symptom of tripping. At the same time, misfires, exhaust problems and other symptoms may occur. Troubleshooting can be permanent or appear occasionally; it can appear during heavy engine loads or during different temperature conditions.

Engine failure during tripping is distinguished primarily by the fact that the combustion process of fuel assemblies in the cylinders is disrupted. Accordingly, this is accompanied by strong vibrations. However, it is fundamentally wrong to consider the appearance of increased vibrations as the only sign of tripling, since there are a number of reasons when the same thing happens.

Trouble engine injector causes

The main problems that contribute to tripling include the following.

Excessive air in the system.
Rich FA.
Problems with the ignition system.
Wear of engine elements, which is accompanied by a drop in compression.

Thus, the power unit begins to triple as a result of either a mismatch in the composition of the fuel assembly, or untimely ignition of the mixture, or the inability to ignite the fuel. Other types of violations are also possible.

To determine the specific cause of tripling, you need to narrow the search, thereby leaving the only correct reason.

They usually start with the fuel system. The air supply is then analyzed. In some cases, this is caused by the failure of certain sensors.
Ignition failure is an equally common cause of power unit tripping. Added to this is a weak spark from the spark plugs. It is recommended to always check the latter as soon as tripping or other ignition-related problems occur. The candles are simply unscrewed and inspected for defects, their color is analyzed, etc. For example, if the insulator of a candle is damaged, then smoke is clearly visible in this place.
Armor wiring testing. If the engine shakes occasionally in wet weather, this is generally an additional symptom that shows tripping due to wires. The signs go away as soon as the engine warms up and reaches its operating temperature. It is recommended to pay special attention to rubber insulators, which tend to dry out and crack over time.

Attention. Rubber caps for armored wiring often deteriorate after repair work. It can be difficult to visually determine a breakdown until the cap is removed.

BB wires

If the engine stalls at idle, the problem may be related to the operation of the ignition system. The culprit is the armored wires, which most often fail. If the wire is damaged, then the spark will break through and, naturally, there will be no spark at the spark plug. The fuel mixture in the cylinder will not ignite. It is best to check the wires with a multimeter.

Among the malfunctions of the wires, one can identify problems with the contacts at the points of connection with the spark plugs or with the coil. Also, the conductor may have various damages. If the insulation is destroyed, this will be accompanied by breakdowns and current leakage. In addition, increased wire resistance is also considered a malfunction. This also negatively affects sparking and the operation of the ignition system.

Trouble injection engine: find the fault with your own hands

The engine runs rough both on gas and at idle speeds

Interruptions in engine operation in all modes indicate either problems in the power system or irregular valve timing. But, however, there may be more serious problems - such as burnout of the piston crown or breakdown of timing parts (for example, breakage of valve springs or burnout of a valve).

Typical malfunctions of the power system include clogged injectors, fuel filters, air leaks and are determined through comprehensive diagnostics. Even cleaning the injectors of a modern diesel engine requires quite expensive equipment, let alone repairing the injection pump... Therefore, if the diesel engine is running “hot” at idle, it is best to contact a qualified specialist. Self-repair can lead to unjustified expenses - if you randomly replace parts, then diagnostics and repairs will cost a pretty penny. Sometimes, even for a specialist, it’s a mystery “why does a diesel engine stall?” becomes a tough nut to crack - modern fuel equipment cannot be diagnosed by eye, and the abundance of electronics does not make the task easier. If old diesel engines could operate practically under water (provided that it did not enter the intake tract), then a modern engine can simply stall in wet weather.

Causes of malfunction

Motorists are wondering: why does the VAZ 2107 engine suffer from injector problems? Many owners of injection VAZ 2107 encountered the fact that the engine began to stall. This malfunction is typical for the entire family of Lada engines. What are the reasons for this effect and where to look for the problem:

Fuel pump and filter.
Injectors.
Spark plugs and high-voltage wires.
Air filter.
Throttle.
valves.
ECU and sensors.

Solution methods

When the reasons for the throttling of the injection-type VAZ 2107 engine have been determined, you can proceed directly to analyzing options for eliminating the problem. Before you begin, you need to understand that you need to know the design features of the motor.

Fuel pump and filter

The first place to look for the cause begins with the fuel supply. First, you should check the fuel pump for functionality and whether there are any malfunctions. If this element does not show visible signs of damage, then it is recommended to disassemble it and check it.

Many experienced car enthusiasts advise, after the fuel pump, to start replacing the fuel filter element, since this is where fuel can poorly pass to the injectors. The fuel filter, according to the service documentation, must be changed every 30-35 thousand kilometers.

Injectors

The next place to look for trouble is the injectors themselves. They may be clogged due to the use of low-quality fuel or defective due to their service life, in other words, worn out.

The elements are checked using a special stand, which not only diagnoses the condition, but also cleans the elements. If there is a damaged or worn part, it is better to replace it with a new element.

Spark plugs and high voltage wires

Loss of spark can also lead to engine malfunction. The next unit that needs to be examined is the ignition. First of all, it is recommended to diagnose the spark plugs. To do this, you need to pull them out from the block head and visually inspect them for cracks. Next, it is recommended to clean the spark plugs from accumulated dirt.

The next stage of diagnosis is to ring the contacts using a multimeter and measure the gap. In most cases, such diagnostics show that the spark plugs are not suitable for further use and should be replaced.

Another element of the ignition system that directly affects the ignition of the air-fuel mixture is high-voltage wires. How well and economically the motor will work will depend on their condition. Therefore, it is recommended to inspect them for damage and also test them with a multimeter.

Air filter

A dirty air filter can lead to the engine not receiving enough air into the combustion chamber, and accordingly the formation of the air-fuel mixture will be disrupted. Therefore, it is recommended to inspect the element, and if it is found that it is dirty, it must be replaced.

Throttle

A dirty throttle valve also prevents the normal flow of air into the engine. To diagnose the unit, it is necessary to dismantle it. If you find that dust and other foreign objects have accumulated on the walls, you should clean the part. To do this, you will need a special product or liquid for cleaning carburetors. This operation can be performed by any car enthusiast without any problems.

valves

Burnt-out valves can cause the engine to start to misfire, since a gap is formed between the seat and the exhaust valve, through which exhaust gases flow back into the combustion chamber, thereby disturbing the balance in the air-fuel mixture.

To diagnose the unit, it is necessary to dismantle the block head. Often, already burnt-out valves are the first sign of wear on the piston group, and accordingly everything leads to a major overhaul.

ECU and sensors

The last place to look for a problem is the sensors. Thus, failure of one or more measuring elements can cause a tripping effect. Therefore, the motorist will have to check them manually, since the electronic control unit cannot always recognize that the sensor has failed.

Reason one - spark plugs

I wrote in detail about how to determine faults in car systems using spark plugs
here .
I recommend reading it - it turned out to be useful, judging by your reviews, thank you.

We unscrew the spark plugs one at a time and look at their insulator.

If it is covered with dense carbon deposits, then it is difficult for a spark to penetrate it. The current seeks the path with the least resistance, so the spark will not be between the electrodes, but will “go” along the insulator to the side. Its energy will not be enough to set fire to the air-fuel mixture. This cylinder will not work.

Heavy carbon deposits on the spark plug electrodes may cause the engine to trip.

We inspect the external condition of the spark plug insulator.

If there are microcracks, then part of the current will not be converted into a discharge, but will escape through these damages. You need to look at the internal insulator, which is screwed into the cylinder head, and at the external one, onto which the armor wire cap is placed.

Any chips or damage can lead to poor sparking or its complete absence.

A superficial breakdown of the spark plug insulator is one of the reasons why the engine began to stall

Large or small gap between electrodes.

Many people have heard or know that for certain engines, ignition systems and types of fuel used, spark plugs with a certain gap are required. Usually its value is indicated by the manufacturer of engines and cars.

In order for the spark plug to work well and the engine not to stall, a certain gap between its electrodes is needed

How to check the spark without special devices on the engine

This is an old, “grandfather” method, some people are afraid of it:

They unscrewed the spark plug;
They put an armored wire on her;
They leaned it with the inner body, the metal part, against the engine;
Turn on the ignition and turn the starter.

Be sure to hold on to the rubber cap of the armored wire, otherwise your hand will shake violently. This is what many are afraid of