Why the starter turns, but the car does not start: causes of the malfunction. Reasons why an injection engine does not start The car does not start, the carburetor turns the starter

Due to changes in the scope of the training program, when preparing for driving courses to obtain driver's license various categories, during training very little time is devoted to the design of the car, including the design and principles of engine operation internal combustion.

Misunderstanding of the purpose of various engine components and the principles of their operation often leads to an incorrect description of the malfunctions that have arisen. One such description is “the starter does not turn the engine.”

With such a description of the malfunction, it is very difficult to understand what the real reason is. Especially if there is no understanding of the level of technical literacy of the car owner. In some cases, this description of the malfunction may mean that the electric motor drives the flywheel and crankshaft of the engine, but does not start.

Starter

The starter is electric motor DC. The main purpose of this structural element is to set in motion the connecting rod and piston group to ensure the initial compression of the fuel-air mixture (FA) in the cylinders. To ensure engine starting, spinning the flywheel to a frequency of 50-70 rpm is sufficient.

At this speed of rotation and the normal state of the cylinders, pistons and rings, compression of the fuel-air mixture is ensured to the degree necessary to ignite the fuel assembly and transfer the energy of the ignited mixture to the shoulders of the crankshaft. Then the process occurs independently.

Thus, the electrical device does not directly affect engine starting, but is only an auxiliary unit for the initial spin-up of the crankshaft.

The main purpose of using this electric motor is to eliminate the need for physical force and ensure ease of use of the vehicle.

Starter design

Structurally, the starter consists of three blocks:

• DC motor
• solenoid relay
• bendix (gear that transmits torque to the flywheel of an engine with an overrunning clutch)

The power supply to the electric motor winding is supplied not directly from the battery, but through the ignition switch. At the same time, when the lock is closed, an electric current is supplied to the coil of the retractor relay, causing it to operate and close the contacts located inside the retractor coil housing, supplying current from the car battery to the commutator brushes of the electric motor through the contact pins hidden under the casing.

Starter malfunctions

Starter malfunctions are divided into two categories

• mechanical failure or wear
• damage electrical diagram

Since the motor shaft spin-up device consists of two electrical elements, damage to the electrical circuit is also divided into two subcategories:

• electric motor malfunction
• Solenoid relay malfunction

Malfunction of the mechanical part of the starter can be repaired by replacing the bearings or bendix.

Failures of the electrical component of the structure are eliminated by replacing the entire blocks, perhaps with the exception of replacing the carbon brushes.

Starter malfunction and cause

The starter hums, but does not turn the engine.

Indicates that the electrical circuit is being closed and power is being supplied to the motor brushes. The electric motor is in working condition. The holding coil of the solenoid relay does not operate and the bendix does not move. Bendix gear does not engage with flywheel gear. The electric motor operates in idle mode. The cause may be either mechanical or electrical in nature.

Mechanical part. The force from the relay retracting element is transmitted to the bendix through a plastic lever shaped like a grip. If there is high resistance to the movement of the bendix along the rotor shaft, this plastic part breaks. Bendix does not translate into working position, and the starter rotates without transmitting torque to the flywheel.

An indirect cause of a breakdown of the plastic grip may be wear of the teeth on the rotor shaft of the electric motor or wear of the teeth on the mating part of the bendix. To repair, you will need to disassemble the starting unit and replace either the lever itself or the lever and bendix.

Other mechanical reason idle speed starter is the destruction of the teeth on the engine flywheel. The malfunction refers to a motor failure and is not directly related to the operation of the drive. The likelihood of such a malfunction may be indicated by the activation of all working elements of the starter, the spin-up of the electric motor and the transfer of the bendix to the working position, which is detected by a characteristic click when turning the ignition key.

To confirm the likelihood of such a breakdown, you should move the car with 3rd or 4th gear engaged without turning on the ignition by 0.5 m. This will lead to a shift in the position of the faulty part of the flywheel. Repeat the start in normal mode by turning the ignition key. If the engine starts, then it is necessary to check the condition of the flywheel at a service station.

In technically complex starters with planetary gearboxes, the gearbox teeth may break. This requires replacing the entire unit. The planetary gearbox is not available as a spare part.

Electrical part. If the starter hums but does not turn the engine, the fault may be localized in the solenoid relay. Solenoid relay mounted on the starter housing and having terminals for electrical connection, has two windings:

• retractor
• holding

The purpose of the windings is different and therefore they create different forces. The retractor winding is designed to close the contact pins and transfer voltage from the battery to the brushes of the electric motor. Retaining - designed to create a force sufficient to reliably engage the Bendix gear and the toothed rim of the engine flywheel. Idle operation indicates normal operation of the retractor winding and contact closure.

When there is an interturn short circuit in the holding winding, the bendix is ​​not fixed in the working position and it is ejected from engagement. Torque is not transmitted to the connecting rod and piston group and the engine does not spin up. Repair is carried out by replacing the solenoid relay. If a separately supplied relay is not available, the starter is replaced entirely.

The starter does not rotate when the ignition key is turned

The problem is mainly related to the electrical circuit. The cause of the malfunction may be the following elements:

• ignition switch contact group
• protective relay
• solenoid relay
• electric motor brush assembly

Initially, you should check the operation of the starter relay located in the relay block, replacing it with a known good one. The starter relay is a standard 4-pin. If you have sufficient electrical installation skills, you can use relays from any manufacturer, ensuring the correct connection.

Another cause of the malfunction is the lack of contact in the wire going from the starter relay to the solenoid relay. If the terminal is not sufficiently secured, the wire falls out of the mounting socket and voltage is not supplied to the pull-in and holding windings of the pull-in relay. can be eliminated by crimping the terminal and restoring the electrical connection.

Malfunctions of the solenoid relay and brush assembly are eliminated by overhauling the starter and replacing the faulty parts.

On the mechanical side, the starter rotor plain bearings may wear out and “stick” to the magnets.

The starter turns, but does not start

There are situations when the starter turns, but the engine does not start. In some cases, the cause of such a malfunction may be the starter itself, namely its technical condition. The electric starter motor consists of two elements - a stator and a rotor.

The starter rotor is secured in the starter housing through plain bearings. When the sliding bearing pressed into the toe of the housing, which is directed towards the flywheel, wears out, the position of the rotor changes and it sticks.

When the ignition switch is worn out, the current consumed by the electric motor increases, which leads to a sharp decrease in voltage in on-board network car. When it drops to 9V, the electronic unit of the engine control system is turned off and no spark is supplied to the spark plugs. Accordingly, the starter turns, but the engine does not catch because there is no spark.

Such a malfunction is often detected in cold weather, but may not be related to the technical condition of the starter itself. This may be due to the condition and charge battery or the viscosity of the used motor oil provided that the engine itself is in normal technical condition. In this case, the starter may be new, it turns, but cannot grab the engine.

Due to the low battery charge, all the current is used to spin up the electric motor and flywheel of the power unit. The voltage decreases and there is not enough charge to supply a spark or spin up the fuel pump to supply gasoline to the combustion chamber.

In this case, with a single start, the battery state may be sufficient to spin the crankshaft to the starting speed. The compression of the fuel-air mixture occurs to a sufficient extent, the engine is ready to start, but does not catch due to the lack of spark or fuel.

Another reason for the engine not starting may be wear of the engine parts itself, which does not allow compression of the fuel assembly or the presence of resistance to crankshaft rotation, for example, when the thrust rings are worn. This does not apply to starter faults.

The simplest and most easily eliminated reason that the internal combustion engine spins but does not start is the lack of fuel in the tank or too much fuel. low level. On some vehicles, the fuel tank is designed in such a way that when the vehicle is parked on a hill and the fuel level is low, the pump is not able to capture fuel and deliver it to the engine. This can be solved by simply adding gasoline or diesel fuel.

When turning the key in the ignition, the driver is accustomed to seeing a repeating pattern. First, the dashboard lights up, displaying the current battery charge and the amount of fuel in the car’s tank. After this, the starter is activated and the crankshaft begins to rotate.

If the engine is working properly, then after a few revolutions of the crankshaft the engine will start. But sometimes the following situation occurs: the starter turns, but the car is definitely not going to start. What to do in this case? A variety of situations can be the culprits, so you need to start looking for what happened.

In this article we will look at the most common problems that lead to the engine not starting. We will try to talk in as much detail as possible about the problems that a car owner may encounter.

The internal combustion engine only operates if the following conditions are met:

1. A sufficient amount of fuel and air mixture enters the engine cylinders.
2. IN right moment(and to be precise, after the air-fuel mixture is compressed) the spark plug produces a high-power spark.
3. The camshaft and crankshaft rotate at the required frequency, which is strictly selected. Only in this way does the gas distribution system work correctly and the chambers are filled with a combustible mixture in a timely manner.

When the driver turns the ignition key, voltage is applied to the starter relay, thereby activating the electric motor. Its function is to engage the flywheel with the crankshaft. Then the crankshaft begins to rotate, its angular momentum is converted into reciprocating movements of the pistons.

When the cylinders begin their work, this subsequently leads to movement camshaft. The latter is needed in order to promptly open the valves to fill the combustion chambers with the mixture.

Camshaft

The internal combustion engine power system is responsible for the timely delivery of the combustible mixture. As soon as the piston moves to the upper compression point, the spark is supplied high voltage. Thus, when the mixture is ignited, a small explosion is created, the expanded gas affects the piston and it moves, moving the crankshaft. We have described the principle of starting an internal combustion engine; remember that engine modifications may be different, so the starting algorithm may differ.

Operation of an internal combustion engine

In almost 50% of cases, the engine refuses to start due to the fault of the starter, that is, it may be faulty. Another part of the situations occurs when the engine cranks the crankshaft properly, but the engine starts after several attempts. But it also happens that the engine does not start at all, the reasons may be different, so you need to study the common causes of problems.

Driver inattention

The human factor can play a cruel joke and you can simply harm your car. Let's say you forgot to stop at a gas station or didn't turn off the alarm. In the first case, everything is clear - if there is no fuel in the tank, then it will not enter the cylinders. And in the second example, if you forget to turn off the alarm, the fuel pump will be deactivated and it will not be able to pump the mixture into the engine.

It also happens that some intruder plugged the exhaust pipe of the car, and then the engine also will not start. Sometimes this happens due to the driver’s negligence, for example, when reversing the car, the car buried itself in the ground and the pipe became clogged with earth. Such circumstances are not among technical faults, but you will definitely spend a lot of nerves on this.

Problems with the starter

Even a less experienced motorist will be able to tell by the sound how the starter works. You can easily understand by the sound how the starter turns the engine; many motorists have also encountered a buzzing sound from the starter; this occurs when there is no contact with the flywheel.

Car starter

Before disassembling half of the car, you must first check whether the starter is working properly. We advise you to make sure that when it is fully functioning, there are no alien clicks or knocks.

The starter can be considered faulty in the following cases:

Fuel system malfunctions

Even the most serviceable starter and a brand new battery will not be able to start the car if there are difficulties with the fuel supply. Next, we will look in detail at what needs to be checked in fuel system, and how to quickly find a fault.

Fuel pump

For carburetor and diesel engines this unit is located almost next to the cylinder blocks. Injection engines are equipped with an electric pump; it is installed directly in fuel tank. About her proper operation can be judged by the short vibration after turning on the ignition.

Fuel pump

If we consider carburetor internal combustion engines, they have a mechanical cam drive on the camshaft. It’s not difficult to check the functionality yourself; to do this, disconnect the hose from the inlet fitting and lower it into any container. Next, pump up the fuel a little using the manual pumping lever, and after that you can start the starter. If the result is negative and fuel is not pumped, then clean the mesh located in the upper part of the pump.

If this does not help, then carefully inspect the membrane and valves of the fuel pump. When you replace all damaged parts, the functionality of the pump will be fully restored.

Fuel filters

Along the way of delivering fuel from the tank to the engine, there are several filter units: coarse meshes (they are located in the fuel receiver, on the fuel pump and carburetor). There are also paper filters along the entire fuel line; they are needed to remove fine particles, if any are found in the fuel. Therefore, if fuel does not enter the cylinders, check all filters. If you find a completely clogged filter, you should replace it with a new one.

Fuel filter for VAZ 2110

Fuel filter

Injectors and throttle

All gasoline engines operate on a mixture of air and fuel; it is prepared in the carburetor or in the manifold (on injection cars). In the first option, the liquid passes through a system of nozzles, channels and nozzles. In the second case, fuel is supplied by injectors according to signals received from electronic unit control unit (ECU).

The air supply is regulated by a throttle valve; depending on the design, it can be controlled mechanically or electric drive. If possible, disassemble this entire assembly; we also recommend cleaning the throttle itself. In addition, we advise you to check whether fuel is entering the engine - to do this, press the spool of the fitting. In this case, gasoline should be sprayed under high pressure; if the pressure is too weak, then you need to check the filters and fuel line.

Throttle valve in different positions

On carburetor engine should be judged by the sharp opening of the throttle, which will spray a portion of the fuel mixture. Remember, spark plugs for gasoline engines should not be dry. To do this, carefully unscrew them and inspect them; a small layer of the fuel mixture should be visible on them. If some spark plugs are completely dry, then you need to check whether a signal is being sent to the control injectors; this can be done with a multimeter.

For gasoline engines, spark plugs should not be dry.

If there is a signal at the injectors, you need to move the ramp so that you can gain access to the injectors. If gasoline does not spray or flows in a weak stream, this indicates that it is clogged. Therefore, it should be replaced, but if it is not possible to purchase new ones, then as a temporary option, they can be cleaned.

Injector ramp

As for diesel internal combustion engines, the unit responsible for preparing the fuel mixture is - fuel pump high pressure. If a problem arises with nozzles of this design, it is better to contact a specialized service, as you will need professional equipment.

Problems with electronic systems

To check the functionality of the ignition system, it is necessary to remove the spark plug from one cylinder. Before turning on the ignition, you should make sure that the spark plugs are touching the cylinder head with their skirt. Then we try to start the car, a purple or blue spark should appear on the spark plug. If there is no spark or too weak, then you need to check whether the ECU and ignition coils are functioning normally.

Spark to spark plugs

Other reasons for difficulty starting the engine when the starter is running

• The timing belt has broken, slipped a few teeth or loosened. In such a situation, the gas distribution phases most often go astray. For this reason, the engine will not be able to start. To solve this problem, you should adjust the belt correctly according to the risks. If you set the belt correctly, the engine will work again. The only bad thing that can happen is if, after the belt jumps, the valve and piston meet. This situation will damage the engine and will have to be done major renovation engine.

  

  Timing belt

• One of the mounted units was jammed, for this reason there will be strong resistance to shaft rotation. To find which link exactly has the problem, you first need to loosen and remove the timing belt. Then you need to manually turn the pump, generator or power steering. It is worth noting that you will be able to get to the service station only if the pump is driven by a belt.
• The crankshaft rotates with noticeable force; this may be due to mechanical defects, for example, the connecting rod is broken or piston group has serious defects. Check how the engine rotates; to do this, set a high gear and tow the car a little. If nothing interferes with the rotation and it occurs smoothly, then this is not the problem.

  

  Broken connecting rod

• Failures are sometimes caused by electromagnetic interference, for example, from the starter or other units. In this case, it will be very difficult to clearly understand where the cause of the problem is hidden, so it is worth contacting specialists.
• Failure of sensors(crankshaft position sensor, Hall sensor). If they fail, the engine will receive the wrong amount of fuel mixture, and ignition will occur at the wrong time. All this will lead to the fact that the engine will soon begin to kill itself, so it is important to monitor the condition of the sensors.

  

  Hall sensor

Now you know why the engine may not start. If you find the reason, but you do not have the necessary skills, then it is better to contact a specialized car service center. Try to monitor the health of your car so that in the future you do not have to make major repairs to the internal combustion engine. We wish you good roads!

The starter engages, but the car does not start. What to do?

One of the most common problems that car owners often have to deal with is engine starting problems. The reasons why the engine does not start can be divided into three groups depending on the engine’s reaction to an attempt to start it:

1. The internal combustion engine “does not turn”;
2. the power unit turns, but does not start;
3. the engine starts poorly.

Let's look at each problem separately.

Why doesn't the engine turn over when trying to start?

In this case you need to check:

• battery - it may be low. To restore the car's performance, you need to remove the battery and charge it with a special charger or install a new battery;
• contacts on the battery terminals - it happens that they are oxidized or not seated tightly. If this is indeed the case, then in the on-board network, when the starter is turned on, the voltage drops sharply, while at the battery terminals the voltage remains unchanged when starting. To correct the situation, you need to strip the wires and tighten the terminals on the battery;

• crankshaft and attachments - you should make sure that the crankshaft, as well as the pulleys of the cooling system pump and generator, rotate easily. If one of these elements is jammed, it will need to be repaired;
• flywheel ring teeth or starter clutch gear - if a visual inspection does not show anything, the car should be towed to experienced repairmen who can detect the breakdown;
• starter solenoid relay - there are a lot of problems with this part (broken circuit, loose tips, oxidation of wires, stuck armature and much more). In any case, diagnostics of the starter operation is required. If this particular element is faulty, it is best to replace it.

Why does the engine turn over but never start?

If, when you try to start the car, you cannot start the engine, then the reason for this may be:

• discharged battery or poor contacts at its terminals;
• malfunction of the ignition system - the most often suspected elements are high-voltage wires, spark plugs, module or ignition coils. It is necessary to inspect these components of the ignition system for breakdowns, cracks and other types of damage in order to identify the cause of the malfunction and eliminate it;

• Incorrect connection of high-voltage wires - not always, but still quite often the inattention of the car owner himself leads to malfunctioning of the engine. So, if you decide to replace the explosive wires yourself, you need to connect them in the strict sequence described in the vehicle operation and repair manual;
• non-functioning spark plugs - often motorists when changing engine oil, air and fuel filters, antifreeze, brake pads forget about spark plugs. Thus, having worked longer than their service life, they cease to perform the functions assigned to them properly. This may indeed cause difficulty starting the engine;
• broken valve timing - it is necessary to check the alignment of the marks on the camshaft and crankshaft. If a discrepancy is identified, their correct relative position must be established;
• a faulty engine control unit, its broken circuits or sensors - first of all, you should pay attention to the sensor that informs the ECU about the position of the crankshaft, and the DTOZH, which shows the temperature of the antifreeze/antifreeze. Due to problems with DTOZH, the car will start until the hot engine has completely cooled down. As soon as this happens, starting the engine will be difficult; in particular, these symptoms clearly appear in the cold season;
• lack of fuel in the gas tank - the problem may be trivial and consist in the lack of gasoline in the fuel tank, which will be indicated by the fuel level indicator located on dashboard car;
• clogged fuel filter– if the fuel filter has not been replaced after ten thousand kilometers or more, this may cause difficulties when starting the engine due to its blockage.

Malfunctions characteristic of an injection-type engine:

• faulty idle speed control - when starting the power unit, you need to lightly press the accelerator pedal to slightly open the throttle valve. There is a high probability that the reason is precisely the IAC, if such actions lead to nothing, and the engine starts and immediately stalls;

• engine starting is blocked by the immobilizer - if the red LED flashes, informing that the security mode is activated, this indicates the need to replace the ECU;
• lack of power to the fuel pump - in this case, you should check the contacts, relays and fuses responsible for the operation of the fuel pump;
• insufficient pressure in the fuel system - you need to check the fuel pump for functionality and clean its filter;
• malfunction of the injectors - you should check the integrity of the electrical circuit, clean the injectors or, if this does not help, replace them with new ones.

Malfunctions characteristic of a carburetor type engine:

• failure of the Hall sensor - in this case, a voltmeter needed to diagnose the sensor or its replacement will help;
• the circuit from the switch to the Hall sensor is damaged - to make sure that the circuit is really broken, it should be checked with an ohmmeter;
• broken switch;
• incorrectly set ignition timing;
• air leakage from outside into the intake pipeline - you need to inspect the fittings and hoses, check their fit and tightness of the clamps.

Why does the engine refuse to work?

If we are talking about the injector, then possible reasons The resulting malfunction may be:

• clogged fuel filters;
• leaky injectors;
• a fuel pump that does not create the proper pressure in the system;
• pinched hoses.

For the carburetor of one of common reasons the reason why the car refuses to start is the lack of fuel in float chamber what could be caused long-term parking cars. Launch cold engine in this case it is quite difficult, however, knowledgeable craftsmen find ways to bring their personal transport to life.

It should be noted that cars are currently equipped with injection-type engines. Of course, carburetors are still found, but only on older car models. Therefore, car owners of modern foreign cars and vehicles domestic production, it is worth paying more attention to the reasons characteristic of power units injection type.

Thus, in order to understand why the car engine does not start, you need to diagnose many systems for operability. This can be done independently, however, if you lack knowledge about the structure of car mechanisms and experience in repairs, you should contact qualified technicians at a service station. Professional diagnostics and, possibly, unforeseen repairs, although they will hit your budget, will save your nerves and precious time.

Video

The cause of the malfunction may be the following:

Turn the key, the starter rattles and... the engine does not start. Every car owner faces this problem sooner or later. What to do in this situation?

In general, there are many reasons why the engine may not start and it is impossible to consider them all in one article. However, there are “basic” conditions that are necessary for a successful launch. We will discuss them now.

For a successful start, a fuel supply at operating pressure, air and a timely spark are required. It is also extremely important to prepare the correct fuel-air mixture. These conditions need to be checked first when the engine refuses to start.

Checking the spark plugs and spark

If the engine does not start within five seconds, there is no use turning the starter. You can try to start it again, but it’s unlikely to help. Moreover, operating the starter for too long can lead to overheating and even fire.

If you try to start a carburetor engine for a long time, gasoline will flood the spark plugs and make further starting attempts impossible in principle. The injectors have a purge mode, so the spark plugs can be dried without removing them from the car - you just need to press the gas pedal to the floor and turn the starter.

But these are half measures. First of all, you should unscrew at least one spark plug, put the wire back on it and position the spark plug on the engine so that there is a distance of about three millimeters between the metal part of the spark plug and the metal of the engine. Turn on the starter and make sure that there is a uniform spark between the spark plug contacts. Do this check for each candle. If there is no spark on any spark plug, then there are global problems in the ignition system.

These could be:

General faults:

• Faulty spark plugs (carbon deposits, destruction of insulator)
• The high-voltage wires are faulty (the insulation is broken, the current flows “to the left”, not reaching the spark plug)

For injectors:

• Ignition module is faulty
• There is no power to the ignition module. Power is supplied from the engine control unit, but the signal to the unit comes from the ignition switch. Therefore it is possible.
• Engine control unit faulty

Errors in the ignition control system are usually visible during diagnostics and cause the Check Engine light to turn on.

For carburetors:

• Contact carbon stuck in the ignition distributor cap (distributor)
• Resistor burnout in the distributor rotor (in the distributor runner)
• Burning or backlash contact group(for contact ignition)
• Switch malfunction (for contactless ignition)
• Ignition coil malfunction
• No power to the coil. Power to the coil is supplied through the ignition switch, so it is worth checking it

When there is no spark on only one spark plug, you need to replace this spark plug with a new one or change it high voltage wire. Spark plugs that are too wet should also be replaced with new ones or at least dried in a flame. This is necessary because current will not be able to pass through wet contacts and there will be no spark.

If there is a spark on all spark plugs, check the fuel supply.

Checking the gasoline supply

You can indirectly determine the supply of gasoline to the cylinders by appearance candles. If the spark plug removed from the cylinder is wet and smells of gasoline, then everything is fine with the fuel supply. However, it is better to make sure of this more reliably.

On injection engines To do this, you need to relieve pressure in the fuel system using a special valve at the end of the fuel rail. Unscrew the cap and press the valve with a screwdriver. Gasoline should squirt out from under the valve. After this, release the valve and turn on the ignition. At this time, the fuel pump must start, restoring the released pressure in the system. If the pump is silent, turn on the starter. When the pump does not work even when the starter is turned on, there is most likely a malfunction in its power supply system.

If the pump starts working, then we check the pressure in the fuel system again, releasing it through the same valve in the ramp. Splashing gasoline again indicates that everything is in order with the fuel supply system. When gasoline does not splash and does not appear from under the valve at all, we can talk about a faulty fuel pressure regulator in the rail (constantly bleeds gasoline through the return line into the tank) or some kind of plug in the main fuel line (for example, due to freezing of water in low-quality fuel ).

On carburetor engines Checking the fuel supply is much easier. It is enough to remove the air filter cover, move the throttle lever of the first chamber of the carburetor, simulating pressing the gas pedal, and see if gasoline sprays from the spray nozzle. You can pump gasoline into the carburetor using the manual pumping lever, which is found on all mechanical gasoline pumps.

Checking the air supply

In the air supply system, malfunctions occur extremely rarely and boil down to either a tightly clogged air filter or to blockage of the air channel by a foreign object. Such malfunctions are unlikely to occur on a well-maintained personal vehicle. But if the car is, for example, a service car or recently purchased, it would be a good idea to make sure that the filter is intact and that there is no rag stuck in the channel after a recent repair.

These are basic actions that can be quickly performed when the engine does not start. If there is a spark at all the spark plugs, gasoline enters the engine and everything is in order with the air supply system, you need to “go deeper”.

As was already said at the beginning of the material, it is difficult to describe all the reasons why the engine may not start in one article. Therefore, we present only a general list.

• The starter does not develop starting speed
• Insufficient on-board electrical voltage (weak battery)
• Lack of compression in the engine cylinders (worn out piston rings, valves stuck)
• Violation of valve timing (timing belt breaks or jumps one/several teeth)
• There is no signal from the crankshaft position sensor or other “vital” sensors of the injection system.
• Engine control unit malfunction

And others. Finding such faults is more difficult to do in outdoor conditions, especially if it happens in winter. You need to take the car in tow and pull it to a garage or car service.

Problems that become noticeable when starting the engine are considered a fairly common problem among car owners. These include the situation when, after turning the key and turning on the ignition system, the starter turns, but does not start. You can find the causes of such a malfunction yourself without contacting a service center.

Possible reasons

The difficulty in diagnosing breakdowns of this kind lies in finding the area where the problem is localized. To find it, you should check some parts of the car.

Spark plugs, battery and fuel filters

Spark plugs create sparks that ignite the air-fuel mixture in the engine cylinders. If this part becomes unusable or becomes covered with accumulated carbon deposits, this can lead to the starter turning but not starting.

If the battery charge reaches zero, the car will not be able to start, so it is better to always maintain the optimal condition of this part.

Fuel filters are a part of the car necessary to filter out some of the dust and rust. Thanks to their work, purified gasoline enters the system. If for some reason the filters fail, the engine may not start when the starter is cranking.

Terminals, flap and fuses

The battery terminals should be given special attention, since novice drivers may forget about their condition. If this part oxidizes, there may be a problem.

The throttle valve acts as a mechanical regulator of the channel flow area necessary to regulate the level of its medium. A problem with the starter can be caused by a clogged part.

Fuses - the cause of the problem may be a violation of their integrity.

Tank and exhaust pipe

The level of gasoline in the tank is measured by a special sensor equipped with a float. If the mechanism is faulty, the arrow on the dashboard will indicate that there is fuel, although the container remains completely “dry”. There is no way to start the engine in such a situation.

If in exhaust pipe there is a foreign object left by an ill-wisher, the engine may not start. The same consequences occur if the driver accidentally stuck the pipe into a snowdrift or soil while backing up.

Condensation and oxygen ingress

Idling of the starter can be caused by the appearance of condensation under the hood due to the air conditioner or corrosion on parts included in the electrical circuit. Moreover, at sub-zero temperatures The engine may also not start due to water getting inside any parts and freezing.. In this case, you should warm up the car.

The cause of the problem may also be oxygen leakage into the fuel supply system, especially for diesel engines. They are often subject to paraffinization - freezing of diesel fuel, since this fuel is simply not able to be pumped through the system in this state.

Additionally, cold weather can cause the spark plugs to flood, resulting in a lack of ignition spark. In some situations, this can be helped by “drying” such parts. You need to disconnect the high-voltage wires from the spark plugs, and then rotate the starter for a while.

Quite often, the problem can occur due to active movement through puddles or regular washing of the engine compartment. Moisture can get on the equipment and motor, which causes electronic malfunctions.

This can be avoided by being careful when washing the engine or driving in rainy weather.

Troubleshooting

Although there may be many reasons why the car does not start and the starter turns, most often this problem arises due to incorrect operation of the ignition and fuel supply systems. They should be checked when no jerking or strange sounds are heard when turning the key. If they are present, you should check the starter itself, because it may be faulty.

Ignition performance

To diagnose the ignition system, unscrew one of the spark plugs and make sure there is a spark. You should put a high-voltage wire on the removed part, and then touch its skirt to the metal part of the motor. If a spark is visible when the engine rotates, replacing the spark plug is not required and the problem should be looked for in another area.

The absence of a spark indicates problems at various locations. In injection cars, you should pay attention to the ignition module, because the cause of the malfunction lies there, but in carburetor models it is better to check the coil.

It is quite difficult to check the ignition module yourself due to its design, but with a coil the situation is simpler. It is necessary to get the main wire of the distributor cover and pull it about 5 mm towards the part of the engine made of metal, without allowing it to touch. Next you need to crank the engine with the starter. If there is no spark, the coil is faulty.

If there is a spark, you should start checking the distributor by removing its cover. If all other parts of the ignition system are working normally, the reason lies precisely in this. You should make sure that this part of the car is free of defects and corrosion. The absence of damage to the distributor indicates the need to look for the cause of the problem in other systems.

It is worth noting that in most cases the problem when the starter turns, but the car does not start, lies precisely in the ignition of the car, so it is necessary to check this system especially carefully.

Fuel supply

The fuel supply system should be checked in stages to gradually eliminate problems with individual parts. It is better to diagnose all elements in the following sequence:

• electric fuel pump;
• mechanical fuel pump;
• injector or carburetor, depending on the type of car;
• fuel filters;
• lines for supplying gasoline.

In injection-type cars, when the ignition system is turned on, the sound made by a running electric fuel pump should be heard. If this sound is absent in the cabin, you should check the pump motor - it could either burn out or not receive the voltage necessary for operation. Its safety system is also diagnosed.

Cars that have a carburetor are more difficult to check, because the pump is driven by a distribution shaft. Because of this, when diagnosing, you should disconnect the end of the hose and the inlet fitting. After this, you need to start the pump pump lever several times - if everything is in order with it, fuel will flow from the fitting or hose.

Additionally, it is worth checking the fuel filter, making sure that there are no blockages in it, otherwise fuel will not be able to be pumped normally through the mechanisms. Next it is checked throttle valve, which should be cleaned if it is clogged.

If the car runs on diesel, you will not be able to diagnose and repair the problem yourself. This is due to the fact that in such models the fuel is supplied at higher pressure compared to gasoline engines, which is why a complex pump design and a special shape of nozzles are used.

In most cases, checking the ignition and fuel supply systems solves the problem when the car does not start, but the starter turns. If such diagnostics fail to find the problem, you should check the relay. You need to look for its problems using the following scheme:

1. Carefully remove the retractor relay from under the hood.
2. Thoroughly clean the starter from dirt, dust and other debris.
3. If there are oxidized contacts, treat them with fine-grained sandpaper.
4. Place the removed part near the car battery and find 2 wires of the required length. It is better to use wires with crocodile clips.
5. One electric drive is used to connect the positive terminal of the battery with the same output on the retractor relay. Contacts with a negative charge are connected by another wire.

When connecting the relay to the wire, a characteristic charge click should be heard. This sound indicates that the relay is working properly, so if everything is in order, the part should be returned to its place.

Otherwise, the mechanism must be repaired or replaced. To carry out repairs, you should first turn off its power from the battery, and then unscrew the rods from the bolt and remove the contact. Next, you can unscrew the screws used to connect the relay to ground, and then pull out the part. After removing the end nuts, the solenoid relay is divided into 2 parts, then the core is removed from it and a new one is installed in its place.

Reassembly is carried out in the reverse order, and then the relay is mounted back on the car. Now you need to check its functionality.

It is worth noting that in models of some car manufacturers, relays with solid structures are used for configuration. They cannot be disassembled, and in case of problems, this unit should be completely replaced.

Checking other parts

If you have checked all the systems that most often lead to the problem when the starter turns but does not engage, you should pay attention to other details. The first one is to check the crankshaft position sensor.

To do this, a thorough diagnosis is carried out electrical circuits and their elements. Malfunctions can be caused by a blown fuse, a break in the power supply system, a breakdown of the control relay, an oxidation process, corrosion or damage to the contacts.

Failure can occur in the ECM sensors interacting with the ECU. There are often cases when a faulty sensor sends incorrect signals to the control unit. Because of this, the operation of the ECU is disrupted - it cannot properly regulate the composition of the fuel-air mixture, which leads to failures in the fuel supply.

The problem may also be caused by electromagnetic interference going to the crankshaft sensor from the starter, which interferes electronic device create the correct signal to the ECU. Under such operating conditions of the DPKV, the engine will not start, although the fuel supply will be normal and the starter will rotate the crankshaft well.

If the timing belt has broken, stretched, or jumped several teeth, this can also cause poor valve timing. In this case, you need to replace the part and align it with the marks. If the malfunction leads to the valves meeting the pistons, you will have to change the engine.

Additionally, you should check the operation of the car alarm. It is capable of blocking engine starting due to failures occurring in the main unit or additional immobilizer.

A possible malfunction may be problems with the operation of the ignition switch. To check, turn on the headlights. If they dim or go out when you try to start the engine, then the part is working properly.

In some cases, it happens that the starter works, but turns jerkily. This sign indicates insufficient contact between the contacts. This is usually due to the installation of poor-quality electrical wiring. The engine may also not start if the starter clicks. This means that his contacts are broken. This problem indicates a problem with the solenoid relay.

It’s much worse if nothing happens after turning the key: the starter doesn’t even turn. This can be understood by the absence of characteristic sounds and clicks. In case of such a problem, it is better to contact a specialist.