List of possible causes. The car has no traction

VAZ-2114 cars, from the start of production, are equipped with eight-valve engines with a volume of 1.5 liters. Since 2007, they have been equipped with an eight-valve 1.6 liter engine with an environmental class of Euro-4. The operation of the car, sometimes incorrectly, brings “surprises” over time. not at full power, traction decreases. Let's try to understand the causes and methods of elimination.

The dynamics of a car, first of all, depend on the stable and stable operation of the engine. When this characteristic decreases, it indicates that there are problems with the engine.

Engine VAZ-2114

Unstable engine operation is caused by the following:

• The fuel filter is dirty.
• The fuel pump diaphragm is clogged.
• They don't work or .
• Insufficient.
• The on-board computer is malfunctioning.
• The injectors are clogged (they need to be cleaned or).
• The clutch disc is worn.
• Malfunctions of sensors that monitor: crankshaft position; coolant temperature; ; detonation.

These are only some of the possible reasons why the engine may not pull well throughout the entire speed range.

It is worth mentioning the fuel pump, which fails. The real state of affairs is determined by detailed diagnostics.

Brief analysis of the causes and their consequences on the VAZ-2114

1. Fine filter dirty . Determined visually. Debris particles present in the fuel tank and gasoline accumulate in the filter and the channels become clogged. There is not enough fuel supplied. "Treatment" - .

   Changing the fuel filter

2. The fuel pump diaphragm is clogged . The reason is the same, there are dirt particles in gasoline. Solved by excavation, washing, blowing with compressed air

   Changing the fuel pump grid

3. The air filter is clogged . For a short time, it can be solved by blowing out the filter, you can knock on a hard object. Ideally, the filter is replaced with a new one.

   Clean or change the air filter

4. Spark plugs do not work or work poorly . Determined by inspection after unscrewing. One of the reasons - . The gaps are checked with a feeler gauge and the required one is installed. To do this, bend the side electrode to the required amount.

   Checking the gap between the spark plug electrodes

5. Formed. The electrodes are sanded with sandpaper (zero), cleaned, and the gap is checked.

   Cleaning spark plugs from carbon deposits

6. The serviceability of spark plugs is checked on a stationary stand. If problems occur, it must be replaced.

   It is best to check spark plugs at a stand in a car service center.

7. Insufficient compression in cylinders . This defect appears as a result of high wear of the cylinder-piston group. The result is increased oil consumption, incomplete combustion of the combustible mixture, and gasoline enters the crankcase. In some cases, it is enough to replace the piston rings, in others a major overhaul of the engine is necessary.

   We measure the compression in each cylinder

8. Failure or breakdown of the electronic control unit . Without special knowledge it is impossible to repair. Diagnostics are carried out using special devices. Re-flashing is possible, or the control unit can be completely changed.

   We carry out diagnostics of the control unit

9. The injectors are clogged . . There are fuel additives, but they don’t give much effect. Replacement may be required, so read the material: ““.

   You can clean injectors at home

10. The clutch disc is worn out . While driving, when the speed increases, the car does not gain the required speed, and slipping is felt. It is checked by experts by starting off in fourth gear. If it stalls, everything is fine with the disk; if the engine is running, then there is a problem. Solved by replacing the clutch disc.

    If the Check engine sensor lights up, it indicates a malfunction of the sensors.

conclusions

Maintenance, which should be carried out according to the manufacturer’s recommendations, will avoid many problems. The only question is where to go, at the “Kulibins”, or at specialized service stations equipped with the necessary equipment and equipment. The choice is up to the vehicle owner. The sooner the prerequisites for the failure of a particular part are identified, the less financial losses in the future. It should be remembered that timely maintenance increases the safe operation of the vehicle.

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.

Modern engines are more powerful, more efficient and pollute less than those of the past. So when your engine's behavior changes, it's immediately noticeable. When a car "loses power" it means something is wrong. This must be clarified immediately, as it may cause an emergency along the way.

For example: Your brake pads are damaged and you didn’t notice it. When driving, they can cause the wheel to catch fire, since brake fluid is flammable. Or the fuel filter is clogged with dirt. This can lead to damage to the fuel pump, which will begin to work with increased load. These are two examples of the main reasons why your car loses power. But other reasons may also arise; we will look at how to identify them below:

Scanning fault codes - must be done if the engine warning light comes on on the dashboard. If this is not the case, then proceed to the next step.

So, the “check engine” light comes on, you need to perform self-diagnosis or connect the scanner to the diagnostic connector. It should be noted that the vehicle control system records an error that appears again the second time the engine is started.

If the engine is running normally, the existing code can itself be deleted from memory. There are times when the engine feels like it’s not working properly, but the light doesn’t come on. It’s just that some faults cannot be detected by the computer. For example: if the intake or exhaust valves are not working correctly, the computer will not detect this, since this malfunction is not related to the sensors.

Checking the air filter— a dirty air filter reduces the air supply to create fuel air mixture. This leads to a drop in engine power and increased fuel consumption. The quality of the air filter material also affects engine performance. Don't go cheap, because possible engine repairs may cost more. There are many stories about how a non-original or cheap filter was installed, subsequently it tore, and after it, the MAF sensor and the rings on the pistons failed along the chain. To check your air filter, open the hood, remove the filter element from the housing and assess the condition. If necessary, replace it.

Fuel filterR— Under certain conditions, the fuel filter may supply less fuel to the system, and this, in turn, affects power. To check it, it is necessary to dismantle it and drain the remaining fuel. Blow out the filter as the fuel flows through the system. A clean filter is easy to blow through. If it is difficult or impossible to clear, throw it away without regret and remember that it can damage your fuel pump.

Check the pressure in the fuel system and at the pressure regulator - The fuel pump is located in the gas tank if you are the proud owner of a car with electronic injection, or on the engine if you still have a car with a carburetor. In many cars, deterioration in performance is associated specifically with the fuel pump. Some cars have a special connector on the fuel line to check the pressure. If you don't have it, you'll have to attach it some effort to connect the pressure gauge. You can find the line pressure value on your engine. Your line has a special regulator installed that releases excess pressure in the line back into the gas tank. It may be incorrectly configured or even leaking. It can be checked using an air pump, gradually increasing the pressure to the specified pressure. If the regulator opens before reaching it, replace it.

Check the ignition system - what is the ignition timing? What is the condition of the spark plugs and high-voltage wires? More detailed instructions for checking are located in the engine. Remember the main thing, do not rely on your own experience or fragmentary knowledge. By missing any nuance, you can ruin any element of the system. For example, ignition coils.

Air flow or pressure sensor - These sensors help the electronic engine control unit determine how much air the engine consumes and how much fuel needs to be supplied to form a fuel-air mixture. If the sensors are faulty, then the computer may incorrectly calculate the amount of fuel, and you will therefore eat poorly. But then why doesn’t the light come on? The computer is programmed for a short circuit or sensor break. If the sensor does not work correctly, then the computer can only tell you that there is incorrect mixture formation in the fuel system and that’s all. You will have to find the source yourself. For this purpose, there are special guidelines for the stages of checking components. See the manual for what parameters the sensor should have.

Checking the timing chain or belt - The crankshaft and timing shaft must rotate synchronously, for this they are needed these belts or chains. You just need to align all the marks that you have on the belt and gears. There are times when the belt jumps one tooth or the chain stretches. But with the proper level of service, you will be protected from this scourge.

Checking the exhaust system for blocking - Modern engines are very complex and automakers are trying to make their cars less harmful to the environment. One of the components of such a system is a catalyst installed in the exhaust system. For some, it may be located directly next to the engine, for others, somewhere under the body. But one thing is constant, he is. When using dirty fuel, which is sold in abundance at our gas stations, over time the catalyst is destroyed and blocks the normal flow of exhaust gases. You can check its performance either using remote thermometers (the temperature after the catalyst should be slightly higher) or by the pressure before and after the catalyst. If you are deprived of such opportunities, then all that remains is to remove it and look at the light. If it is clogged, then it is better, of course, to replace it, but there are practically no conscientious individuals willing to part with a large sum of money; they simply knock it out.

Check compression - To do this, you will need a compression gauge with a pressure gauge whose accuracy you trust. Over time, the rings on the pistons wear off and compression in the cylinders drops, this has an impact on the operation of the engine and its starting. However, it is not only the rings that can cause poor compression. If the valves of the mechanism The timing belts do not fit tightly into their seats, then there will also be a bad result. To identify the source of poor compression, after the first compression measurement, it is necessary to add a few grams of engine oil to the cylinder and measure again. If the compression has risen, then the rings are to blame. If not, valves. True, when measuring compression, your battery must be well charged, otherwise all your efforts will be in vain. It is better to screw in a compression gauge instead of spark plugs rather than use a rubber seal. More convenient.

If all the above points have passed the tests, then all that remains is to check the transmission.

Transmission check - Sometimes the engine produces enough power, but it doesn't actually reach the wheels. If while driving you hear that the engine is working hard, but at the same time you do not feel the car moving vigorously, then the automatic transmission may be slipping or the brake system may be blocked. This can be determined by the car’s coasting; when driving on a horizontal section of the road, move the gear selector to position “D” and look at the behavior of the car. If he tries to slow down immediately, check the brakes. If not, then you need to think about visiting a service station and checking the machine. Of course, you can do it yourself first, at least conducting a parking test.

To conduct a parking test, you will need free space in front of you and a tachometer. It is necessary to warm up the car engine, then apply the handbrake. Press the brake pedal with your foot and move the gear selector to position “D”. Without releasing the brake pedal, press the gas pedal and watch the tachometer reading. If the revolutions are around 2000 (for cars with a turbine about 2200) then everything is fine. If it is more/less than this number, then you still have to go to the service station to check the machine. The test is done for a few seconds and then necessary run the engine at idle speed. Free space in front of you is necessary in case your brakes are bad.

Many people have at least once encountered a situation where a previously working engine “deflates”, and the car seems to grow an anchor at the back. The reasons why the engine does not pull and does not gain momentum are various, but recognizing the signs of most is not difficult even without the skills of an automobile diagnostician or motor mechanic.

Common reasons for all engines

The engine characteristics specified in the vehicle's passport data are provided under certain conditions. This is the normal filling of the cylinders with air, which in an internal combustion engine is the working fluid. This is also an opportunity to heat it to the required temperature in time - to supply a certain amount of fuel of the appropriate quality and ignite it in time (the peak pressure for maximum efficiency should occur at the moment the piston passes the top dead center).

ICE duty cycle

Loss of engine power, regardless of its design, results from a number of common reasons. Let's start with the fuel: its quality remains lottery, but the engine is tuned to a certain grade. That is, the mixture prescribed in the injection maps or set by the carburetor settings may deviate from the ideal one, and the combustion rate of the mixture changes. So, if problems appeared immediately after refueling, you know which way to look.

Filling the cylinders with air is strictly related to the valve timing. It is enough to leave the marks, and the operating cycles of the internal combustion engine will be shifted: already a difference of 1 tooth can significantly reduce the engine power. Moreover, the belt or chain does not have to jump - more and more motors are receiving keyless pulleys, which require rigid fixation of the shafts with special devices during installation. If you don't tighten the pulley, it will one day move from its predetermined position. And it’s good if the engine simply loses traction, and does not hit the piston on the valves that did not close in time, driving them into the cylinder head.

In engines with variable gas distribution, the camshafts (at least one) have the ability to shift so that, with sufficient throttle response at the bottom (small phase overlap), it does not lose at the top (the camshafts move “towards each other”, increasing the overlap phase, which increases power at high speeds ). Possible reasons why the car does not pick up speed are a failure of the VVTi control valve or problems with the phase shifter clutches. We have already discussed this question when talking about.

In addition, the filling of the cylinders is tied to the intake and exhaust resistance. To clog the air filter so much that it loses its flow capacity - this must be done, but oil emissions through the crankcase ventilation system, especially if the piston is already worn out and the oil catcher is primitive, are not uncommon. On a VAZ-2106 it is not difficult to force the engine to “sip oil” through the crankcase ventilation, and even on new front-wheel drive cars (2109, 2110, 2114) such cases are possible. An oily air filter has a sharp increase in resistance, hence the loss of engine thrust.

The exhaust on carburetor cars and old diesel engines is simple, and reducing the flow area sufficiently enough for the engine to start “choking” on exhaust gases can only be done with a powerful blow (when driving over bumps, for example) or with the canonical potato - but at least it’s immediately noticeable.

If the engine with electronic injection does not pull, then the catalyst comes under suspicion in this case. Overheating and ingress of fuel due to malfunctions in the power supply system can cause sintering of its honeycombs. For diesel engines with particulate filters, soot becomes the main enemy: automatic burning of the filter on the go is ineffective, and at a minimum, forced regeneration must be performed.

Problems with the exhaust easily reveal themselves: when the engine is turned off, when you try to start it again, it emits smoke into the intake, the sound of the engine changes, and leaks immediately “crawl” out (the exhaust begins to “cut” to the damaged area).

The engine must not only receive the right amount of air and fuel - it must ignite in time. A gasoline engine requires an appropriate ignition timing; a diesel engine requires an injection timing. Since modern injection engines do not have a separate ignition system, problems with ignition timing are primarily characteristic of carburetor cars and old injection systems with a distributor (the Japanese used such systems right up until the early 2000s). Check the basic advance angle, adjusted by the distributor, and the operation of the advance machines in it (if there is a malfunction, the angle that is normal at idle will begin to “go away” when the speed increases).

A separate case is engines where the distributor is driven by a separate pulley from the timing belt (old Audis and Volkswagens). Here, when replacing the belt, the distributor pulley is placed “as needed” (there are no marks on this pulley!), forgetting that when replacing the belt, the distributor must be oriented with the cam along the risk on the crankcase under it. After such a replacement, the car stops driving because the ignition angles change. For diesel engines with a mechanical injection pump, the initial injection angle is set, in addition, the advance regulator works - they are checked according to the data from the repair and maintenance instructions.

On gasoline engines, we also include spark plugs as suspects: even if the engine operates normally at idle, it is not a fact that the spark plugs will work well under load, when the pressure in the cylinders at the end of the compression stroke increases and the conditions for sparking become worse. It’s worth installing another set for testing: without an oscilloscope that allows you to take voltage curves from a working ignition system, it’s difficult to determine how the spark plug actually behaves under load. In the illustration below, look at the peak voltages corresponding to the moment of spark formation: in the third cylinder the gap is excessively widened, the spark flares up at too high a voltage, and its duration drops (the power accumulated in the ignition coil is not enough for the spark to burn normally).

If we talk about compression, then under normal conditions it decreases with wear so slowly that the decrease in power occurs unnoticed by the driver. An exception is rapidly developing breakdowns (cracks of piston rings, destruction of partitions between rings, etc.). Simultaneously with the drop in power, the idle stability will sharply drop; the final diagnosis will definitely be made by a compression meter.

As for turbocharged engines, the condition of the turbocharger has a good effect on their dynamics. An ideal centrifugal pump (turbocharger impeller) has a quadratic dependence of performance on rpm: as soon as the rpm drops by half, the boost pressure drops by four. Wedging of the rotor due to destruction or coking of the bearings, burning of the “hot” impeller is the probable reason why a turbocharged car does not pull. Here, as with compression, a pressure gauge will help out.

Reasons for loss of power in a carburetor engine

Here it is worth immediately checking the fuel level and the operation of the fuel pump: “underfilling” of fuel immediately reveals itself under load as a loss in dynamics, shooting into the carburetor. Overfilling due to a faulty carburetor shut-off needle will also lead to a loss of engine power, here black smoke and firing from the muffler will become a characteristic sign.

The car's dynamics are perceived better when accelerating, so a defect in the accelerator pump may also be a possible reason for the car's “dullness.” The fact is that all carburetor systems are designed to operate in static modes; as the speed increases, the mixture becomes leaner. The accelerator pump is used to combat this over-depletion: when you press the gas pedal, the diaphragm pushes a dose of gasoline through the shut-off valve into the nozzles that exit into the diffusers. If the diaphragm of the accelerator pump ruptures or the nozzles become clogged, the acceleration of the car will immediately deteriorate so much that it is difficult not to notice. It’s not difficult to check the accelerator pump - after removing the air filter or “turtle” from the carburetor, you need to sharply press the throttle valve drive: your fingers will feel resistance (the diaphragm will create pressure in the accelerator pump), and streams of gasoline should hit the inlet from the nozzles.

In operating modes, the composition of the air-fuel mixture is set statically by a set of fuel and air jets. It is worth blowing them out, and if there are noticeable deposits, rinse them with a cleaner: even if this is not the problem, it will not be a bad idea to maintain the serviceability of the main dosing system.

The injection engine does not pull

Why does the car not pull if the injection systems are equipped with feedback and can self-regulate in a “closed loop”? Unfortunately, the possibilities for self-regulation are not as wide as we would like.

The first enemy of injection systems is insufficient fuel pressure. When fuel consumption is minimal, the correction margin is sufficient for idling. But as soon as you put a load on the engine, the correction will jump to the maximum threshold, but the injectors will still be “underfilled”.

The pressure in the fuel rail is set by three components: the fuel pump itself, the pressure regulator and a set of filters (coarse and fine). The performance of a working fuel pump is several times greater than the engine's needs at maximum flow - this is done so that pump wear affects the engine's operation as little as possible. That’s why a fuel pressure regulator is used, which dumps “extra” fuel either immediately at the pump outlet or from the fuel rail after the fine filter.

In the first case, the fuel rail is called drainless (16-valve VAZ engines, modern foreign cars), in the second - drain. The difference between these systems is the location of the regulator and its operation. On drain ramps, pressure regulators are controlled by the vacuum in the intake manifold; the pressure in the ramp changes depending on the load (at 3 bar, normal for a VAZ, at idle it is 2.3-2.4 bar, take this into account when diagnosing!). On drainless ones, the pressure is maintained constant relative to the atmosphere and is 3.5-4 bar, depending on the car model. An exception is direct injection systems, where the operating pressure ranges from 20 to 70 bar.

Something else useful for you:

The resistance of fuel filters has no effect when measuring fuel pressure “in the plug” (the pump is forcibly turned on with the engine off, when there is no fuel flow in the ramp) and minimally at idle. But under load, an excessive increase in filter resistance reduces the fuel supply to the rail, which will lead to a loss of speed. Therefore, measure the pressure at idle and under load (for example, by hanging the drive axle and braking the wheels in gear). In cases where the idle speed is normal, and problems occur while driving, measuring the pressure only at idle speed (idle speed) is pointless.

Exception stages during verification:

1. Remove the coarse filter (“mesh” at the inlet). This is a known problem for a number of cars - for example, on the second generation Focus.
2. Replace the fine filter.
3. Measure pressure under load.
4. On engines with a drain ramp, clamp or otherwise plug the return line to eliminate the influence of the fuel pressure regulator. On engines with a drainless ramp, the RTD is installed in the fuel pump module; here it is easier to temporarily install a plug washer made of polyethylene or other material under it that is not destroyed by gasoline.
5. Measure the pressure again: if it has increased, then the RTD needs to be replaced, otherwise the pump needs to be replaced.

The second reason for “underfilling” is. Even with normal filter operation, the formation of deposits on the nozzles is inevitable over time. At home, you can only evaluate the shape of the spray pattern by removing the ramp and cranking the engine with the starter (Attention! This procedure is a fire hazard!). A clean nozzle should “dust” evenly, and not produce separate streams or pour to the side. You can evaluate the performance of injectors and compare it with the nominal one only on a bench.

Loss of dynamics is also a consequence of excessively enriched mixture. The fuel pressure regulator cannot be blamed here (the performance of the pump, even when operating without an RTD, is not so high that the correction margin of the injection computer does not cover the enrichment). It is much more likely that the injectors are leaking (again, checked on a bench) or the failure of the sensors that are used to calculate the injection time.

Here the undisputed leader is the mass air flow sensor - an accurate but sensitive device. As the air flow sensor gets dirty and ages, the readings become higher and the car begins to consume significantly more fuel. As a result, the over-enrichment of the mixture can no longer be adjusted according to. But such a malfunction is immediately visible: the car will begin to smoke, the spark plugs will be covered with black soot. On engines with an absolute pressure sensor, failure of the air temperature sensor is more likely (here it is a separate unit, while in the mass air flow sensor it is built-in).

On cars with an electronic throttle, it is worth checking the operation of the servo drive by removing the pipe from the throttle and allowing it to release gas. The throttle should open evenly, without pauses or jamming, indicating problems with the drive gearbox or (the axle, overgrown with carbon deposits, jams in the housing).

Video: Lost power. Power Loss

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When using a car for a long time, sooner or later the time comes when the driver begins to notice that the car is “pulling” worse and worse. To put it another way, the motor does not cope well even with small loads. To overcome them, you have to spin the crankshaft almost to maximum speed. Other signs also appear: sluggish acceleration from a standstill, difficulties in gaining speed when overtaking, etc. In this case, increased exhaust smoke may be observed, but there are no extraneous noises under the hood when the power plant is operating - it runs smoothly and calmly. So what happened, why doesn’t the car pull?

When the engine doesn't pull well uphill...

Causes of power loss common to all types of engines

If there are no other signs of deterioration in engine performance other than loss of traction, it is worth conducting a comprehensive check, which consists of testing the power unit by the “method of elimination”.

Poor quality fuel

In approximately 50% of cases, the “culprit” for loss of traction is fuel. Due to its poor quality or inappropriate octane number (OCN), the engine does not develop power.

You can determine that there is inappropriate fuel in a car tank based on a number of signs:

1. The engine started getting worse.
2. There was detonation. This symptom manifests itself most clearly if fuel with the required octane number is diluted with gasoline with a lower octane rating.
3. When examining spark plugs removed from the cylinder block (BC), you can see black or reddish (brick) carbon deposits, which are uncharacteristic of serviceable parts, which indicates the presence of unnecessary impurities. The first option indicates that gasoline does not burn completely, the second confirms the presence of additives containing metal.
4. Ineffective spark plugs. This can be determined during a sharp increase in speed, when the engine has no reserve for further acceleration. The spark plugs may be clogged due to low-quality fuel or may simply have exhausted their service life.

Solving the problem is not difficult: the low-quality fuel should be drained and the tank filled with suitable fuel with the required octane rating. Clean the spark plugs from carbon deposits, and if their service life has come to an end, replace them with new ones, all at once, in a set from one manufacturer. When carbon deposits appear, you will again have to start diagnosing the cylinder-piston group (CPG) and (or) the fuel system.

It is better to refuel at proven gas stations

Dirty air and fuel filters

If the first of them is clogged and does not allow air to pass through well, the mixture will be excessively rich, that is, it will contain a lot of fuel, which will no longer burn completely. As a result, engine thrust will drop. If the fuel filter is dirty, the result in terms of the operation of the power unit will be the same, with the only difference being that the mixture will become very lean, because there will be little gasoline in it. Contamination of the air filter ahead of schedule can be caused by operating the machine in dusty conditions, and the fuel filter can be caused by low quality fuel.

Violation of valve timing

The main parts of the gas distribution mechanism (GRM) are the intake and exhaust valves. They are “obliged” to open and close only at the right moment so that the fuel mixture enters the cylinders on time and exhaust gases are removed. This process is called phase distribution. If it is violated, you will see that the power of the engine has disappeared, which will begin to “triple” and sometimes have difficulty starting.

Causes of valve timing violations:

• wear, as well as incorrect installation, displacement of the chain or timing belt (most often this is a jump by one tooth (link));
• play or deformation of the pulley on the crankshaft;
• wear of hydraulic compensators, camshaft and (or) its bed;
• burnout or rupture of the head gasket;
• Malfunction of the camshaft position sensor (DPRV).

To restore normal operation of the timing belt, it is necessary to set the position of the timing and crankshaft shafts according to the marks. If the chain is worn, replace it. The same applies to the camshaft with a bed, hydraulic compensators, gasket and DPRV.

Exhaust system resistance

Many people consider the only task of the exhaust system to be to muffle loud sounds and remove exhaust gases. However, modern cars are equipped with a catalyst that reduces the level of emissions of harmful substances. If this element is heavily contaminated or destroyed, the passage of gases becomes difficult. As a result, the engine works “as if strangled.”

In Russia, the problem is solved by simply removing the catalyst. However, you need to remember that in some car models such an operation will require changes in electronics (programming).

Removing the catalyst

Violation of ignition timing angles

We are talking about the moment of ignition of the combustible mixture. It is this that is determined by the ignition timing angle (IAF). When it is deviated toward increase, the mixture ignites early, and toward decrease, it ignites late. Both options lead to improper engine operation and incomplete combustion of the mixture, which may be accompanied by popping noises in the muffler. On injection engines VAZ 2110, 211, 212, 214, 215 (there are also classics with an injector, for example, VAZ 2107), the OZ is set automatically, on carburetor VAZ 2101-2106, 07, 08, 09 (the last two models can be with an injector) it must be installed manually.

Signs of violation of OZ:

• difficult engine start;
• increased fuel and oil consumption;
• drop in throttle response and power of the power unit;
• unstable operation of the internal combustion engine at idle;
• The car does not respond well when you press the gas pedal.

Adjusting the OZ on an injection engine

Everything here is controlled by electronics. First you need to make sure that it is functioning properly and that the throttle sensor is working properly. At idle, it should be slightly open by about 1% (if this is not the case, set up a mechanical drive), the normal voltage at its contacts is 0.45-0.55 V (the car’s bot network should produce 13-14.3 V). When you sharply press the gas pedal, the damper should open 90", and the voltage on the sensor should increase to 4.5 V. If this is not the case, you need to adjust the damper drive and check the serviceability of the sensor (TPS).

To do this:

• take the tester and place it in the voltage measurement position;
• disconnect the connector from the sensor - you will see three contacts - one goes to ground, the other to the ECU (which is connected where, determine from the diagram);
• start the engine and check the supply voltage - it should be approximately 5 V;
• turn off the engine and switch the tester to resistance measurement mode;
• with the damper closed, between ground and the contact going to the computer, the device should show 0.8-1.2 kOhm;
• with the damper open, resistance is 2.3-2.7 kOhm.

If the received data does not correspond to the above parameters, the sensor must be replaced. If this does not work, you should check the ECU.

Setting the OZ on carburetor engines

The simplest and most effective way is to use a regular 12-volt light bulb.

Algorithm of actions:

1. Rotate the crankshaft pulley until the marks match (on the cover - this is the central mark) using a special spanner. If it is not there, turn on 4th gear and push the car until the marks match.
2. From the ignition breaker (distributor), disconnect the thin wire going to the coil and attach a light bulb to it, the second contact of which is connected to ground.
3. Loosen the nut securing the distributor (usually it is a “13” wrench).
4. Turn on the ignition, make sure the lamp is on, and slowly turn the distributor around its axis until it goes out.
5. Now turn the distributor again until the light flashes, and immediately tighten the distributor fastening nut.

Malfunctioning spark plugs

The planned replacement of these elements of the ignition system is carried out after 20-30 thousand kilometers. If the spark plugs are platinum, the resource increases to 100 thousand km. However, the situation when candles (most often one of them) fail ahead of schedule is not uncommon.

This can be seen and heard by a number of signs:

• the engine starts with difficulty, especially in winter;
• idling is unstable, the tachometer needle jumps, the engine may stop periodically;
• when the power unit is operating, increased vibration is observed, for example, the gearbox shift lever shakes;
• weak acceleration dynamics - the car does not develop full power, it “stumbles”;
• when you press the accelerator, “dips” are noticeable;
• fuel consumption has increased.

When one spark plug does not work, experienced drivers say that the engine is “troubling,” that is, only 3 out of 4 cylinders are working.

To find a faulty part, you need to:

• put on dielectric rubber gloves;
• with the engine running, disconnect the high-voltage wire from each spark plug one by one;
• in this case, the nature of the engine’s operation should change, the speed should drop, but if this does not happen, it means that the cylinder is not working - the spark plug does not produce a spark.

It is worth finding out the reason for the poor performance of the part; it is quite possible that it is defective. If other spark plugs subsequently begin to fail, you will have to look for the cause elsewhere - the CPG or the fuel system.

Compression reduction

Often, the reasons for loss of engine power can be associated with simple wear and tear of the power unit. Do not forget that a car aged about 100 thousand kilometers begins to lose its power by 10-15%. If you think the losses are excessive, you need to check the compression. Its nominal value is indicated in the documentation for the machine. For testing, you will need an inexpensive device - a compression gauge, which is a pressure gauge mounted on a hollow tube or connected to a rubber hose equipped with a tip. It is screwed into the cylinder block instead of a spark plug. Next, disconnect the high-voltage wire from the ignition coil. Crank the crankshaft with the starter and note the highest reading on the compression gauge. The operation should be repeated for each cylinder.

Compression check

Pressure below that specified in the instructions by more than 15% indicates wear of the rings, pistons, cylinder block walls, and valves. To solve the problem, you can bore the BC to the repair size, replace the piston rings, grind (or replace) the valves.

Automatic transmission malfunctions

One of the tasks of the gearbox is to transmit torque to the wheels. And if this process is disrupted, then the engine does not gain momentum. You step on the gas and the acceleration is sluggish. The whole point may be a slipping automatic transmission.

There are several reasons for this:

• low-quality gear oil or not what the manufacturer recommends;
• clogged filters;
• clogged valve body channels;
• faulty solenoids (in this case, slipping is observed “hot”);
• wear of friction clutches (maximum service life 200-300 thousand km);
• problem with the control unit.

Most of the above faults are difficult to eliminate in a garage. Therefore, you will have to use the services of a specialized technical station.

If the carburetor engine does not pull

A carburetor is a mechanical device for preparing a combustible mixture of fuel and air. If the proportions of the components in this mechanism are violated, then the engine does not pull.

You need to adjust the carburetor in stages:

1. Jets. Check their calibration - the part supplying air must have a larger diameter than the one through which fuel is supplied.
2. Throttle valve. When you press the gas, it should open completely (if this is not the case, adjust the drive).
3. Ignition system. Its contact version was discussed above. To check the contactless system, turn on the ignition and look at the dashboard voltmeter - its needle will approach “12”, and after a second it will rise higher. If there is no voltmeter, install a known-good switch and check the operation of the ignition system again.

Standard carburetor

Why does an injection engine lose power?

The peculiarity of this engine is a fuel pump that works like an electric motor. If it does not work correctly, the engine speed will be unstable in all ranges. That is, fuel will be supplied unevenly, which will lead to a drop in the power of the power unit. The pump may not work well due to a dirty filter - it needs to be checked and cleaned if necessary. Another reason for the loss of power in an injection engine is the inefficient operation of the injectors, which become dirty during operation. You need to carry out diagnostics using a special (or even homemade) stand and clean the parts or replace them with new ones. The next reason is the incorrect operation of the electronics. These could be sensors or the ECU itself. In the latter case, it is recommended to install a working unit or go to a service station.

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