Engine power is one of the key characteristics of any internal combustion engine. The ability of the power unit to dynamically accelerate the car and maintain the maximum possible speed directly depends on the power. Quite obviously, that a noticeable loss of power indicates certain malfunctions of the motor and its systems.
We also recommend reading the article about it, what is engine torque. From this article you will learn about the dependence of torque and power of the power unit.
The reason for concern can be considered that, that the car stops accelerating normally on a flat section of road without visible ??reasons. Next we will consider, for what reasons a gasoline engine does not develop full power or a diesel engine does not pull, and we will also talk about diagnostic methods and available ways to eliminate this problem.
The motor does not develop power: why is this happening
To answer the question, how to remove engine power, it is enough to remember the passport data of a particular car and the dynamometer stand. Such a stand is a "measuring" device, which allows you to determine the actual power of the motor by the indicator on the wheels. According to the passport, the manufacturer usually indicates the power of the internal combustion engine on the crankshaft. Given this information, it is not difficult to understand, that are stated in the technical specifications, example, 200 c.. on the shaft when checked on a dyno stand will turn into 175 c.. In other words, the measurements on the stand will differ from the passport data.
Now let's understand further. Gradual loss of engine power is a natural process as the power unit wears. I would like to note, that normally it happens gradually and almost imperceptibly for the driver. In other words, engine with mileage 150-250 thousand. Km. may not issue "passport" power, show even less on the stand, while the average loss is 5 -15% depending on the degree of wear and a number of other factors.
We also recommend reading the article about it, what is engine efficiency. You will learn more about this parameter from this article, and you can also consider, why is the efficiency of a diesel engine and a gasoline engine different?.
If there is a drop in power on 20% and more, then the engine needs diagnostics. Note, what if the motor does not reach full power, the following symptoms may be present:
- when you press the gas pedal, there is a pause;
- the car jerks when accelerating;
- the engine smokes (on transient and loaded modes);
- the working temperature of the internal combustion engine increased;
- excessive consumption of fuel and oil is observed;
The presence of the above additional signs helps to find out more precisely, why the engine does not develop power and establish a possible reason. In the list of main malfunctions and failures, experts single out ignition, wear of main nodes, quality of filling and composition of the fuel mixture.
The engine lost power: common causes
- Ignition problems. Too early an ignition advance angle will mean that, that premature ignition of the fuel-air mixture occurs. As a result, the expanding gases oppose the rising piston, rather than pushing it down. In such conditions, engine power will drop noticeably. The same is true for late ignition. Later ignition of the fuel-air mixture leads to, that expanded gases "catch up" as the piston goes down, useful energy is wasted. It turns out, as in the first, and in the second case, the driver intensively presses the gas pedal, fuel is consumed, but there is no full return from the motor.
There are also many problems to mention, associated with a vacuum and centrifugal ignition advance regulator. The point is, that malfunctions of these solutions affect the ignition advance angle and its change in relation to different operating conditions of the internal combustion engine. Example, when the revolutions increase, the regulator shifts the ignition angle.
In other words, the degree of opening of the throttle valve and the increasing frequency of rotation of the crankshaft at the same UOZ do not allow the engine to develop full power. On injection engines, a loss of power may be noted after reflashing or chip-tuning the ECU in order to save fuel. - Cylinder-piston group and timing. As mentioned above, engine power loss is caused by wear of the CPG, failures in timing settings or accumulation of soot in the combustion chamber. As for the gas distribution mechanism, incorrect valve adjustment, coke and soot can disrupt the normal operation of the valve mechanism. To be precise, the tightness of the combustion chamber is broken due to a loose fit (fit) valves to seats. The fit may be broken in that case, if the valves are strongly "squeezed". Engine coking also prevents the valve from closing normally. The point is, that a layer of soot prevents normal fitting. As a result, part of the gases breaks through the loosely closed valves, overheating occurs, valve burnout, valve seats, etc. Coke deposits can additionally smolder under the influence of high temperature, causing the effect of uncontrolled ignition of the mixture, i.e. glow ignition. All this leads to malfunctions and a decrease in the power of the power unit. As for CPG, worn piston rings are a common cause of low compression in cylinders. As a result, gases break into the engine crankcase, that is, the fuel combustion energy is again wasted with great losses. It is not very difficult to determine the reason. It is enough to remove the crankcase ventilation hose and assess the degree of smoke intensity. Presence of heavy smoke, that goes "pulsating", will indicate problems with the rings.
- Filling with a fuel-air mixture and the composition of the mixture. Problems with the filling and composition of the fuel charge can reduce engine power even if, that the engine is working, the ignition is set correctly. The most common cause is a dirty throttle valve or a malfunction of the throttle opening mechanism itself.
Let's add, that working on a lean working mixture will not allow the engine to develop full power. Air suction can lead to impoverishment, which occurs both at the intake, as well as in the fuel system. Another reason is contamination of the jets on the carburetor or fuel injectors / fuel pump grids / fuel lines of the injector internal combustion engine.
The air intake deserves special attention. First of all, it is necessary to check the air filter. Then you should carry out diagnostics of the fuel system. To start, that should be excluded, that the tank is filled with fuel with a low octane number for a specific type of engine. The next step is to check the nozzles and their performance, as well as a gas pump.
As a result
Taking into account the above, if the engine does not develop power, the reasons may be in inflammation, air or fuel supply. Let's add, that a reduction in engine power can also occur regardless of external conditions: ambient temperature and atmospheric air pressure.
If the car "pulls" worse in certain conditions, then it is not a malfunction. Example, high in the mountains engine power, especially atmospheric, decreases. Also, in the summer, the fuel pump or carburetor can overheat in extreme heat.
As a conclusion, I would like to remind you, that the capacity of the intake and fuel system depends heavily on the condition of the fuel and air filters. For this reason, filter elements must be changed in a timely manner, which ensures maximum output from the engine.