A hefty book could be written on this topic. However, a lot of these have been written today: anyone who is interested will definitely find it and read it carefully. We will try to identify the main reasons for this disorder.
First, let's remember what the engine needs to work. It is necessary to create the correct fuel-air mixture, which should be set on fire in time. Therefore, if it is of poor quality or is not supplied in the proper quantity, then you cannot expect good traction from the engine. At low octane, the engine management system will advance the ignition timing to the latest (and is still possible). If the performance of the fuel pump is insufficient or the filter is clogged, there will simply not be enough fuel. The quality of fuel atomization by injectors also affects mixture formation. If they are coked and do not form the correct fuel flame, then the proper composition of the mixture cannot be expected either.
- For the correct formation of the mixture, another component is needed -. And if the air filter is excessively clogged, the engine management system will see a lack of air and limit the fuel supply, which will certainly reduce power. At the same time, the intake of air not taken into account by the engine control system will also disrupt all calculations.
- Now about the combustion initiators - spark plugs and coils that provide them with high voltage pulses. If these components in at least one of the cylinders are not working properly, then they are not getting enough power.
- Optimal filling of the cylinders with the working mixture and timely removal of exhaust gases depends on the correct valve timing. Therefore, jumping the timing belt or chain even by one tooth will undoubtedly lead to a drop in power.
- To ensure an optimal combustion process, the mixture must be compressed. Therefore, cylinder wear, which reduces , has the most negative effect on engine thrust.
- An insufficiently warmed-up engine produces less power, not only because viscous oil resists movement more strongly, but also because the injection system itself limits the parameters. And the engine can be underheated either temporarily, during periods of extreme cold, or permanently - for example, with a faulty thermostat.
- The burnt mixture must be removed in a timely manner, so the influence of the exhaust system on engine power is also significant. If the resistance to gases escaping is high, don’t expect any parameters from the engine. Resistance can increase either due to clogged or jammed exhaust system pipes.
- What else? Besides the engine, the car has other reasons for losing its initial agility. For example, a slipping clutch is worn out or incorrectly adjusted: you press on the pedal, the engine responds, but the car barely crawls... you can also joke: the most commonplace option is the parking brake sticking.
If we have missed any reasons, please supplement the material with your own thoughts.
For the engine to develop full power, the following conditions must be met:
1 - good engine compression;
2 - stable and abundant fuel supply;
3 - a large amount of air.
If one of the above conditions is not met, the engine efficiency will be low.
When traction is lost under load, this means that the engine control unit has entered emergency mode. Emergency engine operation is provided on all modern machines. This mode is necessary for the car to reach its destination not quickly, but safely.
To truly find the reason, It is necessary to perform computer diagnostics of the engine.
Based on the results of computer diagnostics, we will understand which direction to move and where to dig in order to find out the true cause of the malfunction.
If diesel the engine does not have enough fuel, then check the fuel equipment: .
If the diagnostics show that there is enough diesel fuel, but the turbine is under-inflating and there are no errors in other systems, then it is advisable to measure the engine compression.
Lack of necessary engine compression will result in The engine will not pull and develop full power. If there is no compression of the piston, but there is sufficient air and fuel, then a strong explosion will still not occur, thus there will not be a good exhaust, and as we know, the exhaust spins the turbine, so the turbine will not inflate the required volume of air. Lack of air pressure will result in the car not pulling.
The most common reason for lack of air pressure– problems in the operation of the turbine and shutdown of the turbine itself.
Let's consider an engine with variable turbine geometry (the most common).
Turbine shutdown usually occurs due to one of two problems: one is related to the air, the other is due to a mechanical failure of the turbine itself (wear of the impellers, play of the axle).
There are variable geometry turbines that are controlled by vacuum, and there are those that are controlled by an electronic actuator.
The car is equipped with four sensors that completely influence the operation of the turbine.
1 - Boost pressure sensor. It will measure the air pressure in the intake manifold.
2 – Boost pressure regulator. This is the valve that controls the geometry, i.e. turns the turbine on and off.
3 - Intake air temperature sensor. Shows the temperature of the air entering the motor.
4 – Atmospheric pressure sensor. Measures the atmospheric pressure where the vehicle is moving (normal atmospheric pressure relative to sea level).
Most often, it happens that the air intake system in the car is broken. Thus, the turbine drives all the air out (the pipe is torn, there is a poor connection at the joints, the intercooler (air cooling radiator) is cracked).
To identify such a problem, it is necessary to check the entire air intake system for leaks.
The next most common problem is: Faulty geometry in the turbine.
To check the geometry on a car, you need to remove the vacuum hose from the actuator on the turbine itself. Put another hose on it and try to suck in air with your mouth or a special device. After this procedure, the rod that controls the geometry must change its position. If it does not change its position, then there may be 2 reasons: either the membrane in the actuator is torn, or the geometry itself is jammed.
Failure of the boost pressure regulator and boost pressure sensordetected by the presence of errors in them in the results of computer diagnostics.
The boost pressure regulator can also be checked with a vacuum gauge.
We must remember to check the vacuum pump and vacuum tubes throughout the machine for leaks. This is done as follows: disconnect the pipe in some place, apply your hand, you should feel air being drawn in.
A turbine with an electronic actuator can only be checked using computer diagnostics!
Please note that the loss of traction can also be affected by "swirl" flaps (not available on all cars).
We hope that this information will help you identify the reason why your car does not pull or does not gain full power, and also gain enough knowledge to communicate with car service specialists.
In the life of motorists, a situation often arises when, when driving out onto the road and trying to accelerate, it is noted that the engine does not pull.
That is, the acceleration dynamics are very “sluggish”, the car is reluctant to pick up speed, and it feels like something is holding it back.
This problem can arise with almost any car - domestic or foreign, gasoline or diesel, with a carburetor power system and injector.
Often, a drop in traction is accompanied by additional symptoms - extraneous sounds appear when the engine is running, the engine may stall in one of the modes (usually at idle), the crankshaft speed is not stable and “floats”.
But this is not always the case; it happens that the unit behaves perfectly in all respects, but does not develop power.
Main reasons
There are many reasons for this phenomenon and in most cases they are associated with a malfunction of the systems and mechanisms of the power plant.
Some of them are trivial and very easy to fix, others require quite serious repairs.
The main problem with the fact that the engine does not pull is not related to eliminating the malfunction, but to finding it.
In some cases, it is very difficult to determine what caused the reduction in traction effort and you have to go through almost the entire engine.
Therefore, we will try to indicate the main reasons why the car accelerates very “sluggishly”.
Since engines on different cars have their own design features, we will consider specific models.
Power drop on a VAZ carburetor engine
To begin with, let's take VAZ cars with a carburetor power system and an 8-valve timing system - VAZ-2109, VAZ-2110, VAZ-2114, VAZ-2115.
The same power plant is installed on these cars, so the reasons are identical.
Let's go through those components, due to malfunction of which a drop in dynamics may occur.
In general, the main reason that the engine does not pull is a change in the processes in the combustion chambers - a mismatch in the proportions of the air-fuel mixture, the combustion process is disrupted, the filling of the cylinders and the removal of exhaust gases does not occur as required.
Supply system
Very often, a drop in traction occurs due to the power system. Structurally, the carburetor fuel system used on cars from VAZ-2109 to VAZ-2115 is very simple and is almost completely mechanical, so identifying the cause is not particularly difficult.
A decrease in power can occur due to:
In addition to the elements responsible for supplying fuel, a drop in power also occurs due to severe contamination of the air filter element.
Ignition system
This system also takes part in the combustion of the mixture, which means a failure in its operation can affect power.
In carburetor engines VAZ-2110 and others, a decrease in traction can occur due to:
- Faulty spark plugs or changes in their thermal gap;
- Excessive wear of the contacts and the central electrode of the distributor;
- Voltage losses in high-voltage wires;
- Violations of the ignition timing.
Irregularities in the power supply and ignition systems most often cause a drop in power, so testing to identify the cause should begin with them.
If the operation of these systems does not raise suspicions, other components of the engine should be diagnosed.
Exhaust system, timing belt and crankshaft
Loss of traction can also occur due to the exhaust gas removal system, although problems with it rarely occur on carburetor engines.
The main reason here is the reduction in throughput due to large deposits in the muffler. Because of this, exhaust gases, without having time to escape from the cylinders, “choke” the engine.
The reasons for the drop in thrust are also often the gas distribution mechanism and the cylinder-piston group.
Here the reduction in power occurs due to:
- Violations of the thermal clearance of valves;
- Heavy carbon deposits on the valve plates and seats, or their burning;
- Occurrence of rings;
- Limit wear of the CPG;
- Cylinder head gasket failure.
In general, problems with the timing belt and CPG cause a drop in power in any engine - carburetor, injection, diesel. Therefore, we will not mention these mechanisms further.
VAZ injection engines
In injection engines VAZ-2110, 2112, 2114, 2115, both 8-valve and with a timing belt with 16 valves, it is more difficult to identify the cause of the decrease in power due to the more complex design of the main systems.
Supply system
Any injector consists of a mechanical executive part and an electronic control part, and problems can arise in both of them, which will lead to a drop in power.
Let's look at the mechanical part first. Here, cravings can be influenced by:
- Severely clogged mesh filter on the fuel pump;
- Decrease in fuel pump performance due to wear;
- The fine filter is dirty;
- Malfunction of the fuel rail pressure regulator;
- Clogged injectors;
- Fuel filter dirty;
- Air leak in the manifold.
In general, almost every element of the injector executive part can be the culprit for a decrease in dynamics.
The situation is approximately the same in the electronic component.
The operation of the engine with the injector is controlled by an electronic unit, which constantly monitors the parameters through sensors installed on different systems.
The number of these tracking elements is considerable and the breakdown of any of them leads to the fact that the ECU incorrectly evaluates the indicators on the basis of which it controls the executive part.
Because of this, the DPKV readings are disrupted, as a result the operation of the ignition system is disrupted, which leads to a drop in traction.
In injection engines, the exhaust gas removal system more often creates this problem than on a carburetor car, and all because of the use.
The element's honeycombs have a small cross-section, so they become clogged quite quickly, which leads to exhaust gases “crushing” the engine.
Main reasons with engines of other cars
So, on a Mitsubishi Lancer 9, the problem most often arises with the exhaust gas exhaust system. This car uses a double catalyst, which becomes clogged with carbon deposits relatively quickly.
Therefore, many owners of this car, when the power drops, recommend first of all paying attention to this system.
But in the ZMZ-406 and 405 engines, which are equipped with GAZelle and Volga cars, a drop in power often occurs due to:
- Ignition coil malfunctions;
- Losses in high-voltage wires;
- Non-working spark plugs;
- Failure of sensors (primarily DPKV).
But do not forget about the other above-mentioned elements of the power supply, ignition, as well as timing and CPG systems.
In Ford Focus cars, in general, problems with loss of traction arise due to malfunctions of sensors, as well as elements of the power system - especially the fuel module, which includes both a fuel pump and a filter, combined into a single structure.
Much the same applies to a car like the Renault Megane. In this machine, power loss may occur due to:
- Wear of the distributor cover;
- Faulty spark plugs and high voltage wires;
- Weak exhaust system capacity;
- Worn fuel pump and dirty filter elements;
- Damaged injector sensors.
In general, first of all, you should look for the cause in the power and ignition systems, and only then move on to the timing belt and CPG.
If the diesel engine doesn't work
A decrease in traction can also occur in diesel engines. If we look at old cars that have completely mechanical power systems, then the most common cause is depressurization of the system.
Often, beginners and other drivers are interested in why the car does not accelerate or pull. Typically, this problem is related to the engine. At the first sign of a malfunction, it is advisable to carry out detailed engine diagnostics. This will save you from a long search for a breakdown. Almost anything can cause the engine to lack traction.
Owners of new cars often encounter this. If diagnostics fail to identify the problem, you will have to suffer a little. It is connected and will last for 5000 km. This most often occurs in models for which components are assembled in China.
Wear of parts
Why doesn't the car accelerate or pull? In some cases, this may be due to high levels of engine wear. Usually seen on fairly old machines. Most often, the rings suffer, and as a result, compression decreases. Therefore, the first thing to do when reducing power is. If the indicator is less than 11 in at least one cylinder, then a major overhaul of the engine will have to be done.
Sometimes a decrease in engine power indicates the presence of carbon deposits on the valves; this can only be checked by removing the cylinder head. Indirect signs:- Changing the ratio of gases in the exhaust;
- The "check" is lit on the panel.
Filters
The car often jerks due to lack of fuel. Every car has fuel filters. Usually there are two. The coarse filter is either located in the fuel pump, or it is embedded in the hose. A fine filter is installed in front of the injector. If any of these cleaning devices become clogged, fuel cannot reach the injector in sufficient quantities. Which in turn dramatically reduces the efficiency of the car.
Often in summer air filter clogged. In this case, the mixture turns out to be poorly enriched with oxygen, and the fuel does not burn completely. As a result, there is again a loss of power. To avoid such problems, you need to replace filter elements in a timely manner.
Ignition
A modern engine is quite sensitive to ignition operation. An incorrect gap on the spark plug electrodes can lead to failures in engine operation. And, accordingly, to a decrease in engine power. Therefore always. You also need to check their performance on a special stand. This can also be done in a simple but reliable way.
To do this, the candle is unscrewed. A high-voltage wire is placed on it, after which the engine is cranked with the starter. The quality of the spark is determined visually. It should be white and blue. If the spark is red or yellow, it is considered poor quality. You should look for a problem in the ignition system. Most likely, this will be the cause of the loss of power.
Diagnostics
For a more precise definition of the problem, it is advisable. This procedure will help identify problems with sensors and power system operation. To do this, you will need a laptop with a special program. Having deciphered the readings, you need to begin troubleshooting. Most often, the reasons may be the following:
- Malfunction of the crankshaft position sensor. With this malfunction, the “Check engine” usually lights up. The reduction in power occurs due to a mismatch between the pulse supplied to the engine control unit and the actual position of the crankshaft. As a result, incomplete combustion of the fuel occurs, and the engine efficiency decreases;
- . This problem can also affect engine power;
- The reason may be due to. In this case, the “check” will not light up. Therefore, in any case, it is necessary to carry out diagnostics.
Conclusion. As you can see, there are many reasons for the problem and they are all quite diverse. No auto mechanic can tell offhand why the car doesn’t accelerate or pull. In any case, you will have to carry out careful and painstaking work to diagnose and find the causes of the malfunction.
In general, the engine can stop pulling for a variety of reasons - this is one of the most common malfunctions, which can have a huge variety of reasons, and below we will look at the most likely ones, describe their symptoms and examine this issue in detail. After all, one day something can happen to each of us when the engine loses power, without being accompanied by any further symptoms. The engine probably isn't showing any obvious signs of any illness, it appears to be mostly fine and isn't making any unusual noises or vibrations, but it just doesn't pull as well as it usually does. And the problem seems to be getting worse and worse every day, although you probably didn’t even notice when the engine first started to pull worse.
If you are familiar with this situation, then let's look at the following reasons for the reduction in engine torque:
Poor quality fuel
First of all, you need to blame the fuel - remember where you last refueled - perhaps it’s a new gas station or one whose fuel you have not previously had experience driving with. It is quite possible that the fuel simply turned out to be of very poor quality (it happens that you will simply be lucky if your engine simply stops running - after all, someone’s engine will probably stop starting altogether until the owner completely replaces the fuel in the tank).
If you refuel at the gas station where you usually go, and nothing arouses suspicion, go to local communities on social networks, the car club of your region/district, or just a city portal - perhaps the gas station simply had a bad supply of fuel.
However, most often, coupled with loss of torque, the incompatibility of the engine with such low-quality fuel also has other symptoms - for example, instability of engine speed, difficulty starting and some others, depending on how bad the fuel turned out to be and on the car model.
But you can most likely determine the poor quality of gasoline yourself by unscrewing the spark plugs from the engine (for this you will need a special spark plug wrench) - in general, spark plugs can often be used as the primary diagnostic method for certain malfunctions in the combustion chamber of the engine, since they work together most closely with this combustion chamber and at the same time are quickly removable. If the fuel contains a large amount of metal-based additives, then the contacts of the spark plug and the “skirt” of the central diode will have a reddish coating (as if red brick had been crushed onto the spark plug).
Dirty air filter
You may also simply have your air filter dirty, and in this case, eliminating the loss of power will probably cost you less than all other options - just replace the air filter - you can either buy it yourself or replace it yourself.
The problem with a dirty air filter is that the fuel-air mixture that enters the combustion chamber of your engine's cylinders does not receive enough air, and therefore the fuel does not burn completely, because a sufficient amount of oxygen is needed for its combustion. The situation turns out to be similar to that of a person with a runny nose - he seems to be eating enough and leading a healthy lifestyle, but at certain moments in his life (during illness with this runny nose), clogged nasal passages do not allow him to breathe normally.
Dirty or old spark plugs
The spark plugs may well be fouled or excessively worn, in which case if the engine is not running because of them, it is also a relatively inexpensive option to fix the problem - simply clean the spark plugs or replace them. However, it should be borne in mind that both periodic contamination and wear of spark plugs is an abnormal process, and the reason for this most likely lies somewhere deeper, or in the spark plugs themselves.
Dirty fuel filter
The fuel filter, like the air filter, can cause a loss of engine power. And the physics of the process here is similar to an air filter - if in the case described above the fuel did not burn completely due to lack of air, then in the case of a dirty fuel filter, on the contrary, an insufficient amount of fuel is supplied. In this case it's simple.
Mechanical problems with the engine
If all of the above methods did not help, and the engine still pulls the car poorly, then it’s time to entrust the matter to professionals - stop by a good car service center and diagnose the engine’s operation - checking the compression (compression ratio in the combustion chambers), for example, can say a lot about the operation engine, including information about approaching its service life limit and upcoming expensive repairs.
Fuel system malfunction
It is quite likely that the reason for the drop in engine torque is a violation of the normal operation of the fuel supply system to the cylinders, and there may also be a number of reasons why the engine does not gain speed, let’s list the main ones:
- Faulty (dirty) fuel pump due, for example, to low-quality fuel or gasoline being sucked out from the bottom of the tank, where most of the foreign dirt particles have settled.
- Malfunction of the injector or oxygen sensor.
- Leaks in fuel supply hoses or tubes where air is sucked in.
The catalytic converter or exhaust system is clogged
A contaminated catalytic converter or exhaust system line can also cause a decrease in engine torque. In both cases, replacing the corresponding contaminated component will help. It should be borne in mind that the catalyst, as a rule, is very expensive due to the content of noble metals in certain quantities.
We have listed the main and most probable reasons for a possible loss of engine power - you need to remember that there are a great many such reasons, and if you were unable to establish them yourself, then you must definitely go to a car service workshop to entrust this matter to professionals.
