Why the engine does not develop speed: possible causes and solutions
Decreased engine speedsignificantly affects its power and traction. If suddenly your car has lost its former playfulness, you should think about its diagnosis, because such symptoms do not bode well.
In this article we will talk about why the engine does not develop speed and with what it can be connected. We will also consider the probable causes of the loss of power by the power unit and methods for their elimination.
Symptoms of a malfunction
Determine that the engine does not develop speed,which he must develop, is not difficult, especially if you previously went by car and know his native characteristics. Those drivers who encountered in their practice with a similar problem, know that power reduction is characterized by sluggish acceleration, loss of dynamics, traction, as well as engine overheating and increased fuel consumption. Sometimes these processes are accompanied by exhausts of a gray or even black color.
You press the accelerator pedal, and the enginepoorly develops turns? Pay attention to the tachometer. A good motor should instantly respond to an increase in the amount of fuel supplied to the combustion chambers by increasing the number of rotations of the crankshaft. And if this does not happen, you need to urgently look for a malfunction.
The reasons for which the engine does not develop speed, can be very much. Here is a list of the most common ones:
- the power unit does not get warm to the operating temperature;
- low or, conversely, excessive fuel level in the float chamber;
- the accelerating pump is defective;
- clogging jets, carburetor channels;
- suction of air in the intake manifold;
- incorrect timing of ignition advance;
- phase of the gas distribution;
- spark plug gaps are broken;
- clogged air or fuel filter;
- malfunction of mass flow sensors, crankshaft position, throttle position, detonation;
- insufficient compression in the cylinders, etc.
As you can see, the list is quite voluminous, although it can not be called complete. Let's consider more in detail the listed malfunctions.
It will be wrong to require the power unit full power, until its temperature reaches the operating value (900C), especially if it is a motor withcarburetor injection. The cold engine does not develop full speed, even when the air damper is completely closed. The fuel mixture must be heated before entering the combustion chambers. Otherwise, the car will "jerk", and the engine stalls and detonates. So, if you have a car equipped with a carburetor engine, do not rush to leave until it warms up.
Fuel level in the float chamber
The fuel level in the float chamber is alsocan affect the operation of the power unit. If it is lower than the prescribed, the concentration of gasoline in the fuel mixture is reduced. Because of this, the engine does not develop power. When the level is too high, the mixture, on the other hand, is too enriched, but it enters the combustion chambers more than normal. Before hitting the cylinders, it does not have time to warm up in the intake manifold, which leads to the appearance of detonation and loss of speed.
The fuel level is adjusted by bending (bending) the fastenings of the floats.
Accelerator pump, channels and jets of carburetor
Continuing the topic of loss of power carburetorengine, you can not fail to mention the accelerator pump. It is from its serviceability depends on the response of the power unit to the accelerator pedal. The most common problem is fuel supply, and the "nozzles" of the atomizer, through which gasoline is supplied by a thin stream, are to blame for this. To test the performance of the carburetor accelerator pump, you need to remove the air filter so that you can see the first camera. Next, you need to open the throttle and hold it for a few seconds. In this case, a thin (about 1 mm) trickle of fuel must be pulled out of the "spout" of the accelerator, directed precisely into the second chamber. If the jet is low-power or the curve is a sign of clogging of the nebulizer, jets, valves of the accelerator pump. Such a problem is solved by cleaning them.
Air intake in the intake manifold
Another reason for not developingengine speed, can be a banal air intake in the inlet manifold of the power unit. Symptoms of such a malfunction are the difficulty of starting the engine, its "rolling", problems with idling, increasing fuel consumption and, of course, the loss of the number of revolutions. This is all due to a sharp depletion of the mixture due to unaccounted air entering the combustion chambers.
Most often the system is depressurizeddue to wear of the intake manifold gasket. Determine that the injector engine does not develop speed precisely because of air sucking is rather difficult, as it is not easy and find the very place of depressurization. It is better to entrust it to specialists. But you can try something yourself. You can, for example, take a syringe with a needle, fill it with gasoline (or diesel fuel for diesel engines) and process the fuel with the engine connecting the collector with the perimeter. If the gasket between them has become unusable, then along with the air, gasoline will be sucked into the combustion chambers. If, by starting the engine, you notice a positive change in its operation, you can be sure that the reason lies in the suction.
Incorrect ignition timing
It often happens that unluckycar owners, wondering why the engine does not develop speed, forget about the moment of ignition, although it plays the most important role in the operation of the power unit. It depends on the timely ignition of the fuel mixture in the combustion chambers. If the ignition timing is incorrect, you will never achieve any harmonious operation of all engine systems and mechanisms by any means and methods.
In the injector power units for the correctthe corresponding sensors respond. Their job is to collect information and transfer it to the electronic control unit, which in turn adjusts the angle. In carburetor engines there are no such sensors, so the ignition is set manually, by scrolling the top of the ignition distributor.
Set the correct angle independently and withoutspecial equipment is not easy, although it is possible. At the service stations, a special stroboscope is used for this purpose, by means of which the specialist determines the position of the mark on the crankshaft at a certain position of the distributor.
Infringement of phases газораспределения
Violation of the phases of the gas distribution usually occurswhen the timing belt is broken or when it is replaced. Admitting an error in the form of a shift of at least one "tooth" between the gears of the crankshaft and the gas distribution mechanism, you will get a real problem in the form of unstable engine operation, increasing fuel consumption, color exhaust and other troubles.
In order not to fall into such a situation, work onthe replacement of the timing belt and the repair of all the elements connected with it, should be carried out at the service stations. Well, if there is no such possibility, it is necessary to carefully check and recheck the correspondence of the marks on the timing gears, crankshaft and flywheel.
Clearances between electrodes
The next reason why the engine is slowdevelops turns or does not develop them at all, there may be an incorrect gap between the electrodes of the spark plugs. There was a normal car with a normally working engine, but something you did not like, and you decided to change the candles, but did not read the manufacturer's recommendations at the same time. An error in the gap of one-tenth or one-hundredth of a millimeter will inevitably introduce negative adjustments to the operation of the engine. Depending on its increase or decrease, it can be difficult start-up, loss of traction, reduced power, fuel consumption, etc.
If speech has come about gaps, it is necessary to mention andtwo-stroke engines. For them, the candles - one of the most important elements that ensure the stable operation of the motor. So, if the two-stroke engine does not develop revs, the first step is to check the condition of the electrodes and match the gap to the recommended indicators.
Clogged air and fuel filters
Is it worth mentioning once again that filtersIt is necessary to change through every 7-10 thousand km of run, and in special conditions of operation it is twice as likely. Contamination of these elements causes difficulties with the supply of fuel or air to the manifold and leads to a malfunction of the engine. The lack of a normal fuel pressure in the fuel line causes a depletion of the fuel mixture, and when problems with air supply occur, it becomes re-enriched. And in the first and second case, the engine "suffocates", excessively heated, loses power, turns, consumes more fuel.
This fault is eliminated by replacing the filter elements.
Malfunction of sensors
In comparison with carburettor, injectorthe engine benefits from the fact that its operation is controlled by electronics, and if there are any problems the driver learns about them at an error signal on the control panel. He will only have to connect the tester and read the code to determine which of the nodes is out of order. This is due to electronic sensors that control the operation of the main systems and mechanisms. But they are not eternal.
Well, at last, the most unpleasant malfunction,which leads to a decrease in engine speed and loss of engine power - insufficient compression. It is the result of wear of the details of the piston group or the occurrence (coking) of the piston rings. As a result, the pressure in the combustion chambers decreases, and some of the energy from the combustion of the combustible mixture is simply lost.
Compression is measured with the help of a compressometer. Its normal performance, depending on the type of engine, can vary from 10 to 14 kg / cm2. Having found out a similar problem, it is necessary to think about the capital repair of the engine.