Why the engine does not develop speed: possible causes and solutions

Reducing the number of engine speed significantly affects its power and traction. If suddenly your car has lost its former playfulness, it is worthwhile to 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 likely 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 the speed that it should develop, not difficult, especially if you previously went by car and know its 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.

Do you press the accelerator pedal and the engine does not develop enough speed? 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.

Main reasons

The reasons for which the engine does not develop speed, can be very much. Here is a list of the most common of them:

• 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;
• Improperly set the ignition timing;
• The phases of the gas distribution are violated;
• 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.

Cold engine

It will be wrong to require the power unit full power, until its temperature reaches the operating figure (90 ⁰ C), especially if it is a motor with a carburetor 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 motor will stall and detonate. 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 also able to influence 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 carburetor engine, we 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 the 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 will 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. At the same time, a thin (about 1 mm) trickle of fuel, directed exactly into the second chamber, should be pulled out from the "spout" of the accelerator. If the jet is low-power or a curve - this is a sign of clogging of the nebulizer, jets, valves of the accelerating pump. This problem is solved by cleaning them.

Air intake pump in intake manifold

Another reason why the engine does not develop speed can be a banal air intake in the intake manifold of the power unit. Symptoms of such a malfunction are the difficulty of starting the engine, its "rolling", problems with idling, increased 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 depressurization of the system is due to the 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 to find the very place of depressurization. It is better to entrust this to specialists. But you can try something yourself. You can, for example, take a syringe with a needle, fill it with gasoline (or a diesel engine oil 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, when you start the engine, you will notice positive changes in its operation, you can be sure that the reason lies in the sump.

Incorrect ignition timing

It often happens that unlucky car 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 the coordinated work of all engine systems and mechanisms by any means and methods.

In the injector power units, corresponding sensors are responsible for the correct moment. 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 manually set by scrolling the top of the ignition distributor.

Set the correct angle yourself and without special 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 occurs when the timing belt is torn or when it is replaced. Admitting a mistake 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 get into a similar situation, work on replacing the timing belt and repairing all the elements associated 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 that the engine slowly develops rotations or does not develop them at all can be an incorrect gap between the spark plug electrodes. 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 we are talking about gaps, we can not fail to mention two-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 speed, the first step is to check the condition of the electrodes and match the gap to the recommended parameters.

Clogged air and fuel filters

Needless to say once again that the filters need to be changed every 7-10 thousand km of run, and in special operating conditions twice as often. Pollution of these elements makes it difficult to supply 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 in the event of problems with the supply of air, 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 the carburetor, the injector engine benefits from the fact that its operation is electronically controlled, and if any problems arise, 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. If one of them refuses to work, the engine goes into emergency mode. Due to the fact that the electronic unit ceases to receive the necessary information, the operation of the power unit becomes unstable.

Insufficient compression

And finally, the most unpleasant fault, which leads to a reduction in engine speed and loss of engine power, is 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 using a compressometer. Its normal performance, depending on the type of engine, can vary from 10 to 14 kg / cm ² . Having found out a similar problem, it is necessary to think about the engine overhaul.