The car does not develop full power. The engine does not develop full power

Sometimes when driving a car, the driver notices strange things - the car picks up speed more slowly, consumes more gasoline, the engine is heard better. This is most likely due to power loss. There can be many reasons why the engine does not develop proper power.

How to understand that the engine power has dropped

A whole list of parameters affects the smooth operation of the engine.

This is usually felt immediately by the following symptoms:

• The car accelerates more slowly;
• Fuel consumption increases;
• You have to “turn” the motor more in order to somehow accelerate. Engine performance is worse.

Checking indicators on the stand + video

To accurately verify the drop in power, the car must be sent to the power stand. Typically, such devices can be found in car services, tuning shops or dealerships. You can see how this happens in the video.

Reasons for declining engine performance

Change the gas station for a while and watch the agility of the car. Possibly a bad fuel problem.

The appearance of a problem on gasoline (carburetor or injector)

In the case of a gasoline carburetor engine, the reasons may be as follows:

• early ignition. The fuel mixture ignites prematurely, the force of the exhaust gases resonates with the direction of piston movement, resulting in reduced power.
• Late ignition. The mixture does not have time to burn for full cycle engine operation, which means that it does not develop the necessary power.
• Problems with the vacuum ignition timing controller. Found only on carbureted engines!
• Problems with the centrifugal ignition timing controller. They also lead to early ignition.
• Loose fit of valves in their saddles.
• Worn piston rings.
• Throttle stuck.
• A large amount of carbon deposits in the cylinders.
• Intake manifold clogging.
• Using fuel with the wrong octane rating.
• Lean working mixture caused by air leakage, fuel line contamination, air duct clogging;
• Clogged filters.
• Clogging of jets or carburetor fittings, incomplete opening of its dampers.
• Water entering the carburetor.
• Incorrect adjustment of the composition of the fuel mixture.

In the case of an injection engine:

• Clogged fuel and air filters.
• Problems with the electric fuel pump.
• Incorrect operation of the electronic control unit (ECU) of the engine.
• Problems with fuel injectors.
• Incorrect operation of sensors.
• Faulty lambda probe.
• Injector failure.
• Carbon deposits in the cylinders.
• Worn seals, gaskets, rings.

Why the diesel engine does not develop the desired performance

• Poor quality fuel.
• Fuel filter clogged.
• Clogged air filter.
• Failure of the turbocharger (extremely important these days - atmospheric diesel engines are almost never found. Check the quality of the turbines).
• Malfunction of fuel injectors.
• Clogged particulate filter.
• Clogged fuel pickup in the gas tank.

Detailed video about the causes of power loss

Poor throttle response due to clogged catalytic converter

As you know, power can be lost due to the contamination of the catalyst located in the muffler. How to check it?

• Measure the pressure in the exhaust system. If the value obtained is greater than 0.5 atmospheres, the catalyst needs to be replaced or removed.
• Warm up the engine well, measure the temperature exhaust pipe before and after the catalyst. If the temperature before and after is the same, the catalyst is clogged. Similarly, if the temperature after is lower.
• Ringing inside the catalytic converter.

In case of problems with the catalyst, do not remove it without subsequent replacement. Extraneous noise and the overall noise of the engine will increase, the resonance of the exhaust system will be disturbed, and this practically does not affect the engine power. It is better to install a new catalytic converter than to drive without it.

Ways to increase engine power

• Refuel with higher octane rating than recommended.
• Replace the standard air filter with a zero resistance filter.
• Replace standard exhaust system to straight line.
• Engine chip tuning.
• Replacement engine oil for higher quality and less viscous.

Loss of engine power is an annoying problem for any motorist. The car does not drive as it should, and sometimes it is very annoying, and sometimes it is not safe at all, so finding the root causes and eliminating them is an important and necessary task. Good luck on the roads!

At the present time, a fairly common problem in many cars is that the engine does not work at full power. If in this case the problem is not corrected as soon as possible, this is fraught with consequences. Firstly, in this mode, engine wear is significantly increased, which can lead to failure of its main components. Secondly, there is a significant deterioration in the driving characteristics of the car. Thirdly, an increase in fuel consumption is possible.

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Causes of engine failure

Of course, the first thing to do is to diagnose and determine the cause of the problem. In this case, there may be several:

• repeated strong overheating of the engine;
• incorrect operation of the ignition system;
• insufficient filling of the cylinders or the supply of a poor working mixture;
• a significant drop in the level of compression in the cylinders;
• engine malfunctions.

First you should check ignition system because the ignition may be too early or too late.

In this case, the exhaust manifold is very hot, at low speeds the engine will not work well, and when starting with the handle, it will sometimes give back blows. With all this, frequent knocks of a metallic nature in the engine will be constantly heard. If so, just adjust the ignition system. Otherwise, the problem should be sought in the vacuum and centrifugal regulators or in the automatic preignition control devices.

The main reasons for the failure of the centrifugal regulator, which corrects the ignition timing depending on the number of revolutions, are the weakening of the springs and the sticking of the weights. You can determine this using synchronograph.

To eliminate the malfunction, it is necessary to replace the weakened springs with new ones or eliminate the jamming of the weights.

Vacuum regulator may not work properly due to jamming of the ball bearing of the breaker panel, air leakage into the spring plane, or loss of spring elasticity. It is diagnosed in the same way as centrifugal - using a synchronograph. With such a malfunction, it is necessary to correct the operation of the advance angle regulators and correctly set the ignition. In addition, the cause of a decrease in engine power may be a sticking of the throttle on the axle, that is, its incomplete opening. At the same time, the axle should be cleaned and the damper drive should be checked to eliminate the cause of jamming.

The next step is to inspect air filter, and if necessary, wash disassembled, and then change the oil. Plus, it is imperative to check the health of the springs and valves of the gas distribution device, adjust the clearance and replace worn elements.

The reasons for incomplete filling of the engine cylinders with the working mixture can be a large amount of coke and tar deposits in the pipeline, the use of unsuitable fuel, sticking of the float chamber valve and various kinds of malfunctions in the muffler.

They are eliminated, respectively, by cleaning the inlet pipeline, replacing fuel, correcting jams and repairing the muffler. Loss of engine power also occurs when a lean mixture enters the cylinders, which can occur for several reasons.

If the fuel channels of the power system are contaminated and the jets in the carburetor are clogged, it is necessary to thoroughly clean the contaminated channels and rinse the jets well. This also causes a decrease in engine power.

If there is a clogging of the sump screen, seizing of the fuel pump elements or a breakthrough in the diaphragm, the jam should be eliminated first, then the filter and sump screen should be cleaned, and the damaged diaphragm should be replaced with a new one. If there is a suction of air flows at the junctions of the carburetor elements, it is necessary to tighten the bolts and replace the worn seals. Well, a violation of compression in the cylinders is eliminated by setting and adjusting its level.

Thus, with the timely elimination of the problem of reducing engine power, you can avoid rather unpleasant consequences, the elimination of which will take you quite a lot of time and money. Remember that in order to avoid this kind of breakdowns, it is imperative to carry out a periodic complete diagnostics all systems in your vehicle.

› The engine does not develop full power…

Lean mixture entering the cylinders. Filling the cylinders with a lean mixture always leads to a significant reduction in engine power. In this case, the car moves at lower speeds, it takes more time to accelerate on a dry road with a hard and smooth surface if the car's chassis mechanisms are in good technical condition.

The reasons for the formation of a lean mixture are as follows:

clogging of jets and channels in the carburetor, contamination of fuel lines, freezing of water in the power system. In this case, it is necessary to blow out the jets, channels and contaminated fuel lines using a tire inflation pump, and if necessary, clean them with copper wire by disassembling the carburetor;

stuck fuel pump valves, clogged strainer or ruptured diaphragm. In this case, the jamming of the fuel pump valves is first eliminated, the strainer is washed, and the broken diaphragm is replaced or temporarily restored in the manner described earlier;

air leakage at the junction of the carburetor parts, the carburetor flange with the exhaust pipe, the intake pipe flanges with the cylinder block due to loosening of the fasteners, as well as damage to the gaskets. The suction point can be detected with soap suds. A window is formed in the soap suds in the supposed place of suction. Air leakage is eliminated by tightening nuts or bolts, as well as replacing the corresponding seals;

wear of the fuel pump drive lever, clogging of the air hole that communicates the fuel tank with the atmosphere, jamming of the air damper. Eliminate these malfunctions as follows: replace the defective parts of the fuel pump, clean the air hole of the plug, check and, if necessary, adjust the length of the carburetor air damper control cable.

Late ignition. If the engine does not develop full power, it is best to check the ignition installation. If the ignition is too late, the engine loses throttle response. A significant reduction in power occurs for the reason that the mixture does not have time to burn out at the moment when the piston is at TDC. The combustion of the mixture continues as the piston moves down. This is evidenced by increased heating of the exhaust pipeline. It will be too hot, as some of the mixture burns out when released.

You can verify the violation of the ignition installation as follows. Driving in direct gear flat road at a speed of 50-55 km / h, sharply press the throttle control pedal. If the ignition is installed correctly, slight and short-term knocks should appear, disappearing with further acceleration of the car. The absence of knocks means that the ignition is late. Most often this happens when the grade of gasoline used is changed (for example, A-93 was temporarily used instead of A-76 gasoline). In this case, the ignition timing can be tried to be adjusted using an octane corrector (see Fig. 9). To do this, it is necessary to loosen the fastening of the housing 2 of the breaker-distributor on the engine and turn it by hand against the direction of rotation of the cam by one or two divisions of the scale 1 of the octane corrector towards the advance (+), and with strong short-term knocks in the direction of rotation of the cam towards the delay ( -). By adjusting the ignition setting, it is necessary to achieve stable engine operation.

early ignition. A decrease in engine power also occurs when the ignition is too early, when the combustible mixture ignites prematurely and the gas force acts against the piston, which moves to TDC. At the same time, frequent and ringing metallic knocks are heard in the engine, detonation may occur, the engine does not work well at a low crankshaft speed, and sometimes gives back blows when starting with the handle.

If by adjusting the ignition timing using the methods discussed earlier, it is not possible to achieve the desired results, then, obviously, there are malfunctions in the devices for automatically adjusting the ignition timing - centrifugal or vacuum regulators.

Defective centrifugal ignition timing controller. The centrifugal ignition timing controller starts working at 400-600 min-1 and regulates the ignition timing only depending on the crankshaft speed.

If malfunctions occur in the centrifugal regulator - weakening of springs 5 ​​(Fig. 38) or sticking of weights 3 - this will lead to a violation of the ignition timing. When the regulator weights are stuck, the ignition timing at both low and high crankshaft speeds will remain the same. Meanwhile, for high crankshaft speeds, the ignition timing should be earlier.

Late ignition at high crankshaft speeds causes a decrease in power and increases gasoline consumption. If the springs 5 ​​of the regulator are weakened and the weights 3 diverge completely, then even at low crankshaft speeds there will be a large ignition advance, which will also lead to excessive fuel consumption and a decrease in power. The operation of the centrifugal ignition timing controller can be checked in the following simple way.

Without removing the ignition breaker-distributor from the engine, remove the lever 2 of the breaker and turn the cam 1 by hand in the direction of rotation of the roller 4 until it stops. Weights 3 will then open. Then lower the cam, and under the action of the springs 5 ​​weights it will return to its original position. If jamming is detected, it is necessary to eliminate it, and replace the weakened springs.

Faulty vacuum ignition timing controller. On the way, the car has to move both on a flat road and on a road with slopes. Suppose that when driving at a constant speed both on a flat road and on a hilly road, the centrifugal regulator will give only the same ignition advance. But when driving on a hilly road, the engine load and throttle opening are much greater, so the ignition advance must be less than when driving on a flat road at the same speed. The adjustment of the ignition timing when the throttle opening (engine load) changes is performed by a vacuum regulator (Fig. 39).

Rice. 39. Scheme of operation of the vacuum ignition timing controller:

1 - carburetor pipe; 2 - vacuum regulator tube; 3 - housing of the vacuum regulator;

4 - spring; 5 - diaphragm; 6 - thrust; 7 - panel finger; 8 - breaker panel

It may have the following malfunctions: loss of elasticity of the spring 4, air leakage into the spring cavity, wear or damage to the diaphragm 5 located in the middle part of the housing 3 of the vacuum regulator, seizure of the ball bearing 6 (see Fig. 38) and the panel 7 of the breaker-distributor. When the spring 4 (see Fig. 39) of the vacuum regulator is weakened at low and medium loads, the ignition advance increases. If, however, air is sucked into the cavity where the spring is located (if diaphragm 5 is damaged), then the ignition timing will decrease at low loads. If too much air is sucked in, the vacuum regulator will not work at all.

On the way, the serviceability of the vacuum regulator can be checked by shaking the breaker panel on the bearing.

In this case, it should be checked and determined whether the gap between the finger 7 of the panel and the rod 6 of the diaphragm 5 of the vacuum regulator has been increased and whether the rod itself is jumping off.

If, however, a vacuum is created in the tube 2 of the vacuum regulator disconnected from the nozzle 1 of the carburetor, then, if it is in good condition, the breaker panel should turn in the opposite direction to the rotation of the cam.

A more accurate check of the serviceability of the vacuum ignition timing regulator and the elimination of identified malfunctions are carried out by specialists at a car service station.

Violation of clearances in the valve mechanism. It is known that a tight fit of the valve in the seat, i.e., its complete closure, is ensured due to the thermal gap in the valve mechanism. In case of violation of the normal values ​​​​of thermal gaps established by the requirements of the factory instructions for the operation of vehicles, the engine loses power. At small gaps, the valves and their seats burn out. The presence of large gaps in the valve mechanism causes not only a loss of engine power, but also a characteristic metallic knock of the valves. In addition, loose closing, for example, of the exhaust valve due to abnormal clearances is characterized by “shots” in the muffler, and a loose fit of the intake valve is characterized by “sneezing” in the carburetor.

Both small and large gaps in the valve mechanism have a negative impact not only on the efficiency of the engine, but also on the service life of its parts. Abnormal clearances in the valve mechanism are adjusted in the manner discussed earlier.

Wear of piston rings. Piston rings provide tightness between the piston and cylinder, preventing gases from escaping into the crankcase, and also prevent oil from entering the combustion chamber.

With wear of the piston rings (burning of the rings in the piston grooves, loss of their elasticity), the compression in the cylinders sharply decreases, which leads to a loss of engine power, increased consumption of oil, gasoline; black smoke comes out of muffler.

The compression in the engine cylinders is checked using a compression gauge and manually. Manual verification requires skill; you need to do it like this:

unscrew all the spark plugs, except for the spark plug of the first cylinder, and turn the engine crankshaft with the crank until the compression stroke ends in the first cylinder;

then alternately screw the spark plug into subsequent cylinders and again turn the engine shaft with the starting handle. Comparing the effort expended to overcome the resistance to cranking during the compression stroke in each cylinder, it can be assumed which cylinder has low compression.

To check the compression with a compression gauge, it is necessary: ​​warm up the engine to a temperature of 80-85 ° C, unscrew the spark plugs, install the compression gauge tip tightly into the spark plug hole of the first cylinder and fully open the throttle and air dampers;

crank the engine crankshaft with the starter for 2-3 s and note the readings of the compression gauge.

In a serviceable engine, the difference in compression gauge readings between the engine cylinders should not exceed 1 kgf / cm2, and the pressure at the end of the compression stroke should correspond to the following data (kgf / cm2):

ZAZ-968 "Zaporozhets" ... 8

ZAZ-1102 "Tavria". . . … 9.5

VAZ-2101, -2103, -2105, -2106, -2107… 9.7

VAZ-2108, -2109… 9.9

"Moskvich-2141" ... 8.5

"Moskvich-2140" ... 9.8

GAZ-24 "Volga" ... 9.4

Worn or defective piston rings can be identified by the following inspection. After determining the pressure in the cylinders, fill in 23-30 cm of engine oil through the spark plug holes and turn the crankshaft with a starter. In this case, an increase in compression will indicate a malfunction (wear) of the rings or a cylinder, the absence of an increase - a leak in the valves. Coked piston rings are replaced with new ones.

You can try to eliminate a slight burning of the piston rings yourself without disassembling the engine. To do this, prepare a mixture consisting of 50% solvent No. 647 or acetone, 25% kerosene and 25% AC-8 oil and pour 100 cm3 into each cylinder through the spark plug holes. Then crank the crankshaft several revolutions, after an hour add another 50 cm to each cylinder and leave for 7-8 hours. After that, pour 30 cm3 of a mixture of gasoline and oil into the cylinders and drive 20-25 km by car. Then drain the oil from the engine crankcase and flush the lubrication system with liquid oil.

Silencer pollution. During the operation of the car, due to the operation of the engine on an overly enriched mixture, its incomplete combustion occurs. Unburned fuel is thrown out in the form of soot, and part of it settles on the inner wall of the muffler, gradually polluting it. In addition, muffler contamination is also possible at the time of careless reversing of the car on a bumpy dirt road. If the muffler is dirty, the engine loses power. The condition of the muffler can be determined by visual inspection and a slight blow from the outside. A clean muffler produces a high-pitched, metallic sound, while a dirty muffler produces a muffled sound.

A dirty muffler must be cleaned, as this leads not only to a loss of engine power, but also to excessive consumption of gasoline, as well as premature wear of the muffler.

Ignition system malfunctions.
Incorrect ignition setting.
Remove the cap from the distributor. Unscrew the spark plug of the first cylinder. Having rolled a conical cup out of paper, insert it into the hole of the candle. Turn the crankshaft of the engine with the crank or wrench until the paper cup rebounds. Carefully turn the shaft until the marks (the second mark on the damper part of the pulley and the tide of the timing gear cover) are aligned, which determine the ignition moment during the compression stroke of the first cylinder. Make sure that the position of the slider plate corresponds to the high voltage wire coming from the spark plug of the first cylinder. Set the octane corrector scale to zero. Under the sensor-distributor housing, loosen the bolt of its fastening and, with one hand, supporting the slider against the rotation of the distributor housing, turn the distributor housing with the other hand until the red line of the rotor is aligned with the stator arrow. While holding the housing from turning, tighten the distributor mounting bolt. The final check of the ignition timing should be carried out on a warm engine when the car is moving in direct gear at a speed of 40 km/h on an equal section of the road. At hard pressing A slight knocking sound is heard on the gas pedal. If there is no sound, increase the ignition timing with an octane corrector.

Malfunction accelerator pump.
Violation of the fuel supply in the acceleration mode. In low gears, the car does not get the necessary acceleration. Hence the deterioration of its dynamic qualities.
Remove air filter cover. By a sharp turn of the throttle actuator, ensure fuel injection and observe, with well-directed lighting, its entry into the primary chamber. An even strong jet of gasoline should be injected from the accelerator pump sprayer, reaching the mixing chamber without touching the diffuser walls. An uneven or curved jet indicates a partial clogging of the atomizer channels. Complete absence jet may be due to a malfunction and severe clogging of the fuel supply screw of the sprayer and the discharge valve located in it. If during the check it turns out that they are serviceable, you should pay attention to the diaphragm mechanism of the accelerator pump: is it serviceable, is it dirty? This is done in the usual way - disassembly.

Incomplete throttle opening.
With the help of regulation, achieve full opening of the throttle valves. Fully open the throttle valve of the first chamber. In this case, the throttle valves of the first and second chambers should take a vertical position. Reduce the free slack of the throttle cable to the limit by continuing to adjust the position of the cable sheath stop on the engine cylinder head cover. There is another way: raise the throttle pedal in the passenger compartment by loosening and then tightening the pinch screw of the pedal adjustment levers.
TagAZ owners in winter time at a significant sub-zero temperature (-25 degrees and below), they may encounter the opposite problem - incomplete closing of the throttle valve, due to the formation of ice on its walls. As a result, the engine does not slow down and maintains them within 3000-4000 rpm. In such cases, car owners are advised to lubricate the throttle return spring with silicone. You can buy tagaz c190 from dealers in many cities of Russia. This model Taganrog Automobile Plant is the best compromise between a city sedan and a reliable SUV.

Low level of gasoline in the float chamber (poor mixture - pops in the carburetor). The float stroke is adjusted.
Pump up gasoline with the manual pumping lever, not forgetting that the fuel pump has dead spots at which it stops pumping gasoline. If there is not enough gasoline, remove the air filter housing and, without dismantling the carburetor from the engine, unscrew the seven screws securing the carburetor cover, taking care that the spring washers do not fall into the intake tract. Carefully lift the cover 15 mm, separate the gasket and remove it forward along the vehicle. Turn the cover to the left in the direction of the car. Check fuel level.

Malfunction of the gas distribution mechanism.
Valve clearances not adjusted (one or more valves do not close well).
Adjust the gaps on a cold engine, when both valves are closed, the rocker arms swing freely. Start adjustment from the first cylinder on the third mark on the crankshaft damper pulley and the pointer on the timing gear cover. The piston of the first cylinder should be at TDC on the compression stroke. Remove the ignition distributor cover and make sure that the slider plate is against the desired cylinder. The feeler gauge should slide effortlessly and not quite freely. If the locknut is tightened, the adjustment may be disturbed. In this case, repeat the operation. The valve clearances of the other cylinders are adjusted according to the firing order of the cylinders.
The level of contamination of the air filter has reached the limit.

The service life of the filter element depends on the intensity and conditions of its operation, as well as on its resistance to air passage. Increasing the resistance of the air filter leads not only to a decrease in engine power, but also to an increase in fuel consumption and an increase in CO and CH emissions.
There is a certain relationship between the mileage of the car and the degree of filter clogging, which must be taken into account, although this task is not an easy one. Current dry filters consist of porous material (cardboard and synthetics). In both cases, the air purification efficiency reaches 99°. Every 10,000 km of run, the air filter housing should be cleaned and the filter element should be blown through with compressed air from the inside, blowing it from the outside as well. If the road is very dusty, and especially when following another vehicle at close range for a long time, the filter must be replaced.

Too lean mixture.
On the working surface of the insulator and the electrodes of the candles, carbon deposits from light brown to white. Check the fuel level in the float chamber. If it is normal, check the calibration of the jets

Clogged main jets.
Symptoms are similar to a lean mixture. Blow out jets with compressed air

Engine camshaft cam wear
Deaf knock of the gas distribution mechanism. Open valve cover and make sure the cams are worn. Replace camshaft, levers and camshaft housing. In the absence of skill and experience, it is advisable to perform the operation at a service station

Faulty ignition coil.

Inspect the coil visually. Check with a tester or motor tester. If any malfunction of the coil is detected (its increased heating is observed), replace the coil

Violation of the gap between the levers and camshaft cams.

Check gaps with a feeler gauge and adjust if necessary (checking and adjusting gaps between cams and valve levers)

Incorrect fuel level in the carburetor float chamber.
Check and adjust the level (how to check the level in the float chamber)

Engine overheating.

Eliminate the causes of overheating

The valve springs of the gas distribution mechanism have weakened.

There may be light spots on the coils of the valve springs if the spring was deposited before the coils touched. In this case, the springs should be disassembled and checked. In the presence of lighted areas on the springs, the latter must be replaced

Incorrect ignition setting.

Check with a strobe or test lamp. You can check on a car moving at a speed of 30 - 40 km / h: turn on direct gear - the absence of detonation knocks indicates a late ignition. Adjust (checking and setting the ignition timing)

Incomplete opening of the throttle valves of the carburetor.

Press the throttle pedal all the way down. Check the opening of the throttle valves (with the air cleaner removed) by pulling the throttle control lever. Adjust pedal travel

Fuel pump defective.

When driving with the fully open throttle the engine starts to stall due to lack of gasoline. Disassemble the fuel pump and troubleshoot (fuel pump and problems associated with it)

The carburetor accelerator pump is faulty or its drive lever is bent.

Visually inspect the pump drive. Make sure it is correct. Check operation and replace damaged parts if necessary

Beating of the roller of the breaker-distributor.

Make sure the roller beats by shaking it by the rotor. Troubleshoot at a service station

The spring of the movable contact of the breaker-distributor has weakened.

Determine the malfunction visually and eliminate it (adjusting the contacts of the breaker-distributor)