The ignition coil is one of the main elements in the control system gasoline engines. Its inoperability leads to a lack of ignition in one or more cylinders. Therefore, each car owner should know the main signs of a malfunction of the ignition coil, the symptoms that precede the appearance of this situation.
The device is the most conservative part in a gasoline engine. Its prototype was invented in Germany by the engineer Ruhmkorff in the middle of the nineteenth century. It replaced the magneto in car engines in the early 20th century.
The main purpose of the device- conversion of low-voltage electrical impulses with an amplitude of about 12 volts (voltage onboard network car) into high-voltage impulses with an amplitude of more than 15,000 volts. High voltage required for breakdown working area spark plug.
According to the type of execution and ignition scheme, the coils are classified:
- single;
- double (triple, four-block);
- individual.
Single devices are used in systems with an ignition distributor. Twins are used in four-cylinder internal combustion engines without a distributor. One part generates a high-voltage impulse to the 1st and 4th cylinders, the second serves the 2nd and 3rd. Triple and quad coils are sometimes used in six-cylinder and eight-cylinder engines, respectively. IN modern cars individual coils are widely used. They are installed on each spark plug individually. An individual spark plug coil has a number of advantages over conventional ones:
- failure of one of the devices does not lead to a complete engine shutdown;
- it is easier to organize an electronic control scheme;
- the absence of a mechanical ignition distributor makes the system more reliable;
- distribution of impulse load reduces currents, increases the resource;
- facilitates the identification of a faulty device, which is easily performed by computer diagnostics;
- most individual coils have a pulse amplifier, it is controlled by small signal currents, which reduces electrical noise, increases the reliability of electrical equipment.
By type of management are divided into:
- contact;
- electronic;
- with built-in switch (pulse amplifier).
In contact ignition reels, a low-voltage pulse is generated by an interrupter. When the primary circuit is switched by a breaker, an electromotive force pulse is induced in the primary circuit. The device is an autotransformer that increases the pulse amplitude by N times, where N is the transformation ratio equal to the ratio of the number of turns in the secondary to the primary winding. Transformation ratio contact devices exceeds 1000.
IN contactless systems electronic coils are used. Their transformation ratio is greater, they form a stable spark. When repairing, contact and non-contact devices cannot be interchanged.
An integrated commutator is installed on most individual coils, often installed on dual coils. Their disadvantage is a higher probability of failure due to the presence of electronic components.
Malfunction symptoms
Most often, the bobbin does not suddenly fail. This is usually preceded by a series of warning symptoms.
The main symptoms of a malfunctioning ignition coil:
- spark gaps in one or more cylinders, they can be determined using a scanner, by the presence of the engine “triple” effect;
- the appearance of "breakdown tracks" on the body can be determined visually when the engine is started in dark time days;
- the occurrence of cracks, chips in the dielectric zone;
- overheating of the structure;
- burning of rubber tips of high-voltage wires;
- smearing, pollution.
When the above symptoms appear, you need to think about purchasing a spare device. You can't just watch the ignition coil die. In the event of a sudden failure of the coil, further independent movement will not be possible (unless you have individual coils installed).
Reasons for the failure of the ignition coil
Consider the reasons why the ignition coil fails.
natural wear and tear
Like all electrical and electronic blocks, the bobbin has a certain resource uptime. The average service life of ignition coils is approximately seven to ten years of operation or 150,000 - 200,000 thousand miles. The device is operated in extreme conditions with a large temperature difference, humidity, the possibility of moisture, dirt, foreign liquids. In this case, through the primary winding flow high currents, a high-voltage pulse is formed in the secondary winding.
electrical breakdown
Let's figure out why the ignition coil breaks through. Firstly, over time, as a result of high temperature differences, the dielectric insulation cracks, and salty moisture, which is a conductor, can get into the microcracks. For voltages of more than 15,000 volts, formed in the secondary winding, even pure undistilled water acts as a conductor. Secondly, during operation, they change physical properties dielectric, rubber insulation of the tips of high-voltage wires, especially of dubious production. High voltage breakdown may be the reason for the installation of non-standard high-voltage wires, in which there is no distributed current-limiting resistance. A breakdown can occur as a result of severe pollution, waterlogging. Even in the event of a single breakdown in the structure, irreversible changes occur, further operation is not recommended.
Overheat
In some vehicles, the ignition coils are mounted directly on or near the top of the engine. If there is no air access to their structure for natural ventilation (this is possible when installing additional equipment), the device may overheat and fail.
The coil mount must be standard. Some motorists neglect these requirements, "hanging" it on home-made structures.
Wear of candles, high-voltage conductors
Despite the fact that the circuit has a limiting resistance, the wear of candles and high voltage conductors may cause electrical breakdown. Then the load current increases, the bobbin may overheat.
Generator Voltage Regulator Relay Malfunction
Sometimes it leads to an increase in the voltage of the car's on-board network, failure of the electronic amplifier (switch).
Malfunction of the contact group of the lock, electronic switch
If, during parking, the coil is constantly supplied with +12 Volts in case of an abnormal short circuit contact group lock, the device may overheat and malfunction. The same situation is possible in the event of a switch failure.
To prevent premature exit out of order, it is necessary to eliminate as much as possible all possible reasons malfunction of the ignition coil in the car.
Symptoms
The main signs of failure of the ignition coil are the lack of ignition. If this is a single device with a distributor, then in all cylinders, if it is double or single - in those served by it. Not necessarily the absence of a spark is a 100% sign of a faulty coil. Perhaps the limiting resistor has burned out, the candle is faulty, high voltage wire there is a fault in the ignition system. Required complex diagnostics malfunctions.
Visual signs that the ignition coil is not working:
- the presence of "breakdown tracks", scales on the coil;
- change in the color of the dielectric;
- burning contacts and connectors;
- traces of overheating on the case;
- increased pollution.
How to identify a faulty ignition coil
The procedure for checking the health of the coil depends on how many ignition coils are in the car. If your vehicle has individual ignition coils, in order to a high degree probability to determine the faulty one, it is possible to swap the presumably faulty and obviously good coil. If, as a result of this replacement, in the cylinder in which there was no spark, it appears, and disappears in the other, therefore, the bobbin is really faulty. In the same way, you can check dual and block coils, but you will have to modify the circuit, which is not always convenient.
How to determine which ignition coil is not working without making changes to the electrical circuit
To do this, stock up on thick dielectric gloves, dry rubber mat. The use of only ordinary dielectric gloves is unacceptable: they withstand a voltage of 6300 volts after breakdown, a voltage of approximately three times more is applied to the candle.
If your car has two or more ignition coils, if one of them fails, the car should start, but treble strongly. By removing in turn the tips of the high-voltage wires of the candles or the connectors from the individual coils, the stability of the engine is evaluated. If the internal combustion engine has not changed the nature of the work as a result of removing the connector, then there is no spark in this cylinder. If the engine began to triple even more, or even stalled, there is a spark, the bobbin is faulty, or pulses or power are not supplied to it.
multimeter
If the car engine does not start and does not seize at all, the health of the coil can be assessed by a parametric method. For this you need a multimeter. An ordinary coil like a Zhiguli coil can be rang out without difficulty. To do this, first set the measurement limit of the multimeter to the resistance measurement mode of 200 ohms or “diode, continuity” and measure the resistance between the coil terminals + and K. The resistance should be in the range from 0.2 to 1.0 ohms. Please note that during the measurement at this limit, a small error may appear, which will slightly increase the readings of the multimeter. Then the multimeter mode is switched to the limit of 20 kOhm and the resistance value of the second winding is measured (between the K terminal and the copper tip into which the high-voltage wire is inserted). The resistance should be in the range of 1 kilo ohm to 3 kilo ohms (2000 - 3000 ohms).
It is impossible to check a coil with a built-in pulse amplifier in this way, since the output of the primary winding is not connected to its terminals. A frequent malfunction of individual devices is a breakdown of the limiting resistor. It is located under the rubber extension of the coil structure, which is easily dismantled. The resistor should be removed and its resistance measured with a multimeter at the limit of 20 kilo-ohms. It should be in the range of 1 to 3 kilo-ohms.
Megaohmmeter
It is also possible to evaluate the insulation resistance if a megohmmeter is available. Insulation resistance (between the copper contact into which the high-voltage spark plug wire is inserted and the body) must be more than 300 megaohms. This measurement is an estimate. If the resistance is less, the coil is probably faulty, more - probably good, it is impossible to judge more precisely.
A simple three-terminal coil can be checked "on weight", that is, by collecting the simplest circuit. The voltage from the + 12V battery is connected to the + terminal, a high-voltage wire is inserted into the connector, and a candle is connected to the second terminal. The body of the candle is connected to metal part engine. Next, a stranded insulated conductor with a cross section of 2 sq. Mm is connected to contact K. Holding on to the insulation, the other stripped end of the wire briefly touches the metal part of the engine. A spark should jump in the meta of the touch of the engine and through the candle. IN electronic coils the spark of the candle is less intense. It is impossible to experiment with this method for a long time.
Some specialized service stations have self-made test stands. Their use requires special methods.
In order for the coil to work longer, follow the rules:
- install the device on standard mounts;
- do not clutter up the place of the device, providing good ventilation;
- keep clean on the body;
- in a timely manner (before the start of each season of operation) check the spark plugs and high-voltage wires.
The ignition coil is designed to create high voltage, which is later used by a candle to form a spark. Therefore, her good work necessary for the proper functioning of the ignition system. In fact, the coil is a small transformer, the primary winding of which receives standard 12 V from the battery, and a voltage of several kV comes out. It is used in all ignition systems - contactless and electronic. The reasons for the failure of the coil are typical. As a rule, this is a wire break, insulation damage, mechanical deformations. Next, we will consider the symptoms of a malfunction and methods for diagnosing an ignition coil.
If individual coils are installed in the engine, then you can check them by rearranging them to other candles. In this case, it is better not to touch the wiring so as not to damage its integrity.
Ignition coil module
The "spark in a syringe" method
The process of checking the coil using such homemade device simple enough. To do this, you need to connect the coils in turn to the candle of the resulting “device”. Fasteners-crocodile attach to the "mass" of the machine body. At the time of changing the tested coils, the engine must be turned off and then restarted.
Initially, using the piston, you need to set the minimum gap between the wire on the piston and the electrode (1 ... 2 mm). And by adjusting the distance from the wire on the piston to the electrode on the candle, visually look at the process of the appearance of a spark between them. Max distance in this case at different machines will be different, and it depends on the quality and condition of the spark plug, the condition of the electrical system of the machine, the quality of the "mass" and other factors. Typically, a spark during such tests should appear at a distance between the electrodes from 1 ... 2 mm to 5 ... 7 mm.
Before each test of the operation of the resulting apparatus, it is imperative to disconnect the connector from each nozzle so that fuel does not flood the cylinder during the test.
The main thing that can be accurately judged during such tests is a comparison of the state of different coils by cylinders. If there is a malfunction or - this will be seen from the length of the spark compared to more or less serviceable coils.
Insulation resistance test
Another popular verification method is to measuring the insulation resistance value of wires in the coil windings. To do this, you will need a multimeter that can measure resistance. It is better to dismantle the ignition coil from the car to make it more convenient to work. The measurement procedure is simple. The main thing is to know where the terminals of the primary and secondary coils are located, since it is necessary to measure the resistance on both of them.
Before starting work, make sure that the multimeter is working. To do this, turn on the resistance measurement mode and short the probes together. The screen should show 0.
Two multimeter probes are connected in pairs (touch) to the terminals of the primary winding. The resistance value should be in the range of 0.5 ... 3.5 ohms (some coils may have more, you can find the exact information in the reference literature). A similar procedure must be carried out with the secondary coil. However, here the range of values will be different - from 6 to 15 kOhm (similarly, check the information in the reference literature).
Procedure for measuring the insulation resistance of the ignition coil
If the value is small, then the insulation has been damaged in the winding, and you are dealing with a short, most likely interturn, circuit. If the resistance is too high, then this means that the winding wire has broken and there is no normal contact. In any case, it is necessary to carry out repairs, that is, rewind the winding. However, in most cases it is better to simply replace ignition coil, as this method will save you from unnecessary hassle and costs. This applies to almost any car, because the cost of repairs will exceed the price of the coil itself.
If you are dealing with individual or two-terminal coils, then the situation is somewhat different. The value on the primary winding should be similar. As for the "secondary", the resistance value will be identical on both terminals. If the machine has a coil with four terminals, then the test must be done on all terminals.
Also note that it is important to consider polarity when measuring secondary resistance. In particular, with the black probe of the multimeter, touch the central terminal (“ground”), and with the red probe, touch the tip rod.
The oscilloscope will show all
The most professional way to test a coil is to use an oscilloscope. Only he can give full information about the condition of the ignition system, and in particular, the ignition coils. Therefore, in difficult cases, it makes sense to use an electronic oscilloscope and an additional software. This is especially true when there is a so-called interturn short circuit on the coils of the secondary voltage (with high voltage).
If using an oscilloscope to remove a graph of the values of the operating voltages in dynamics (seen in the figure), then it can be understood from it that the ignition coil will be the cause of the possible malfunctions described above. The fact is that when an interturn short circuit occurs in the secondary coil, the energy that could potentially be stored in this very coil decreases, and this, in turn, leads to a decrease in the spark burning time, that is, misfiring. This is especially noticeable when you sharply press the accelerator pedal.
Coil whole
Coil punched
Results
Checking the ignition coil is not difficult at all. This can be done by anyone, even a beginner, a motorist. The simplest and effective method- measurement of insulation resistance on the primary and secondary windings. To do this, it is better to remove the coil for the convenience of work.
Remember that when a malfunction is detected, it rarely makes sense to carry out repairs, in particular, rewind one or the second winding. Much easier to buy and replace new coil whole ignition.
In most cases, if the car’s engine is unstable, the speed fluctuates and the car often stalls at an intersection, this is associated with a reel. It turns out that the ignition coil breaks through. How to fix it is the topic of this article.
Reel or ignition coil
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The reason for the problems of the bobbin is the regular use of the part, the heavy loads that affect this mechanism of the car. Of course, this increases the likelihood of breakage.
Broken bobbin symptoms
A clear symptom of a broken reel is failures in movement. This is especially noticeable when accelerating or maneuvering the car.
Many motorists, having found such signs on their car, begin to look for reasons in the circuit. After replacing a couple of questionable wires, dips reappear.
Also alarming in this case is the black exhaust that appears "on a cold" when the engine is started. That's exactly how it works diesel engine which breaks. Wild rattling and failure of revolutions, which is exacerbated by errors in the on-board computer.
A punched bobbin is always a crack through which a spark breaks through. It punches on the screen (the steel shell of modern coils), and that, in turn, on the block.
The insulators of the modern bobbin are rubber. This is certainly good, because such material is not affected by electricity. However, over time, the rubber "gets tired" - in other words, crumbles.
The reasons that lead to problems with reels can also be called nutritional problems. For example, the voltage level should not be less than 11.5 volts. This can happen if the car's battery is used for a long time. In this case, the performance of the battery drops, which reduces the voltage level.
Faulty wiring is also the cause of bobbin breakage. Coils get very hot from this. To solve this problem, it is enough to replace the wiring with a new one.
It is noteworthy that if the temperature of the bobbin during its operation is less than 150 degrees, repair is still possible. However, if this temperature is exceeded, complete combustion reels.
Bobbin check
There are three test methods:
- Connectors are disconnected from the reel in turn at the moment when power unit starts to tremble. If, when the connector is disconnected, the dips in speed do not increase, then the element is faulty.
- The bobbin is removed. The degree of counteraction of the current on the windings is measured. The voltage is measured directly between the mutual contacts, as well as between the connector and the contacts. The current level must be equal to 6-8 kOhm on the first and 0.4-2 Ohm on the secondary windings.
- You can verify the malfunction of the reel by the error code generated by the on-board computer.
mending
Finding a new ignition coil today is not particularly difficult. In order to repair a broken reel, it is not at all necessary to buy a whole reel. Auto parts stores sell quite a lot of repair kits, among which you can easily choose the option for your car.
Note. When choosing a reel repair kit, you should pay attention to the number of motor valves.
On the other hand, in remote areas of the Russian Federation, sellers are in no hurry to sell spare parts in the form of repair kits, preferring to sell complete reels, which is beneficial for them in all respects.
One repair kit costs no more than 150 rubles. This also includes an insulator and sealant. candle well. If the car engine is 4-cylinder, then you need to take 4 repair kits at once.
Bobbin replacement
In some cases, repairing the bobbin is not possible. Then settling the snag comes down to replacing the part. You should be aware that during the replacement process it is important to test the conformity of the replaced elements. Be sure to fully match the models.
It is also important to clean all contact areas from grease stains and dirt. It is extremely important to check the places for the fact of rusty traces. Corrosion, as you know, increases the level of resistance several times, often causing weak contacts. Obviously, it should be disposed of as soon as possible.
The algorithm for replacing the bobbin may differ, depending on the model of the coil. So, the old-style bobbins are replaced as follows:
- The battery is de-energized;
- The wire going to the distributor is disconnected from the coil;
- The nuts securing the wires on top of the bobbin are unscrewed.
Note. If traces of rust are found on the contacts, then you should apply VD-40 liquid here, wait a bit, and then unscrew the nuts. Do not forget to mark the exposure of the wiring.
- Loosen the nuts securing the bobbin to the car body;
- Move the coil to the side and dismantle.
The reel of the new design is often referred to as the ignition module. The device, like the old-style coil, generates a high voltage current.
The module dismantling process algorithm looks like this:
- The negative terminal of the battery is thrown off;
- The engine protection is removed, which is a plastic lining (applies only to some car models);
- The block of wires is removed from the reel;
- They are removed towards the armored wire (on a 4-cylinder engine - there are 4 of them, respectively);
- Two latches are unscrewed with a key of 13;
- A large fastener is unscrewed with a key of 17;
- The module is taken out;
- A special key unscrews the bolt that fixes the module to the holder.
So, having learned how the ignition coil breaks through, the owner can only try to fix it by replacing the repair kit. If this fails, the whole reel must be replaced.
The car's ignition coil is responsible for sparking and igniting the combustible mixture in the engine. internal combustion. Malfunctions of the ignition coil lead to the complete inoperability of the motor or to its unstable operation.
An ignition coil, sometimes called a bobbin, is a high voltage transformer with two or more windings. The main function of the module is to convert low voltage pulsed voltage into high voltage to generate a spark in spark plugs.
Coils are of two types:
- single-spark;
- double-spark.
The latter are used in two-cylinder engines of older motorcycles, small cars and sports models.
The classic switching circuit is contact, when the high-voltage wire in turn through a mechanical or electronic system distribution is connected to the spark plugs.
Ignition coil device 1. additional resistor; 2. cover; 3. core 4. high voltage winding; 5. low voltage winding; 6. magnetic core; 7. insulator.
Symptoms of a failed ignition coil
Coil malfunctions manifest themselves in different ways, but most often the car will not start. The starter turns when the ignition key is turned, but the engine does not respond.
Also observed:
- unstable sparking;
- engine troit;
- power reduction;
- starts badly;
- at certain speeds, failures in the operation of the motor are felt;
- car suddenly stalls.
The reason for this behavior of the car may be mechanical damage body of the device. A crack or chip forms a high-voltage voltage leak to ground. This leads to a decrease in high voltage and, as a result, to unstable sparking or sparking outside the combustion chamber.
The winding may heat up, indicating an interturn short circuit. As it heats up, the insulation of the wires is destroyed and over time, the electronic system is completely closed.
The symptoms do not specifically indicate that the bobbin is out of order, and appear with other malfunctions.
Checking the ignition coil
Not all drivers know how to check the ignition coil. And along the way, such knowledge can come in handy. If the car shows the symptoms described above, then first check for a spark. To do this, it is enough to disconnect the high-voltage wire and, with the starter running, bring it to any metal part of the body by one or two millimeters. If you see stable powerful spark, then everything is in order with the reel.
If there is no spark, then you need to know how to check the health of the transformer winding. Check for low voltage at the primary terminals. Lack of voltage indicates a faulty wiring, alternator, battery, etc. Pay attention to the terminals when high current their connections often burn and spark. This causes oxidation of the conductive surfaces.
When checking the high voltage module, it may turn out that there is a spark, but it is not powerful enough and ignites unreliably combustible mixture. This happens for several reasons:
- mechanical destruction of the housing or cable of the high-voltage module;
- interturn short circuit of the secondary winding;
- reduction of winding insulation resistance;
Over time, microcracks appear in the device case. How to check the health of the ignition coil in this case. The winding comes into contact with a humid atmosphere and loses part of the energy of the high-voltage pulse through it. It's easy to check. Open the hood in a dark garage. If the coil glows as electrified, luminous electrical energy flows from it in all directions or sparks in any place, then its body has lost its insulating properties.
The winding does not burn out during this use, but the engine power drops. However, the load on the windings increases and they burn.
A slight bluish halo around the module does not count - this is the norm and is not included in the signs of a malfunction of the ignition coil. Just check how hot the ignition coil is. Its temperature should not exceed 90 degrees.
But when the ignition coil is heated, the transformer will burn out.
The turn-to-turn short circuit, as well as the loss of resistance between the windings, reduces the transformation ratio, the current consumption increases, and the windings begin to heat up and then burn.
For some time, weak sparking may occur, but the verdict is unambiguous - the winding will burn out. Also, the windings burn due to the small gap of the candles.
Malfunctions of ignition coils with oil transformers
The windings are placed in a container with cooling transformer oil. The main signs of a malfunction of such a device are:
- overheat;
- oil flows.
If you do not look closely at the fact that the oil is flowing, the coil burns out. In some cases, it can be opened, the seals replaced, or a layer of sealant applied. Usually the windings burn due to an interturn short circuit.
But if the oil burns and evaporates from the body, then only a replacement will help. Do not believe those craftsmen who offer, if the ignition coil is heated, change the oil and seal the device. A closed winding always burns out. Also, the lack of oil leads to the failure of the transformer.
Checking the health of the bobbin using a tester
Many users are wondering how to check the ignition coil with a multimeter. It's simple. Better use an electronic tester.
Ring the primary winding. Its resistance is usually around 0.5 ohm.
Now measure the secondary winding. If it has not failed, then its resistance varies from 200 to 500 kOhm. But the indication of the resistance of the coils within these limits does not mean that the device is working properly. Turn-to-turn short circuit is almost impossible to check in this way. To do this, you need a generator and an oscilloscope.
Features of checking the ignition module Alfa Romeo
In some Alfa Romeo models, two candles are installed on each cylinder. Therefore, in the Alpha high-voltage module, there are two secondary windings that supply a spark impulse to the candles.
You can check the performance of both Alpha high-voltage windings by all the methods described.
To determine the malfunction of the Alpha 146 bobbin, check the resistance of the windings. They should be:
- primary - 0.3 Ohm (+/- 12%);
- secondary - 7 kOhm (+/-12%).
Feel free to take other readings of the module resistances as the cause of problems in Alpha 146.
Recognizing the failure of the coils is not difficult, but determining why they burn and fail, losing their efficiency, is much more difficult.
It's no secret that in order to start an internal combustion engine and make it work (unless you have a diesel one), you need two things. It's gasoline and spark. In the absence of at least one of them, alas ... You will not go anywhere. If it is enough to pour gasoline into the tank, then everything is much more interesting with a spark ... We need a whole bunch of devices: a battery, a generator, an ignition coil (reel), an ignition distributor (distributor), and finally, candles. Let's take a look at the reel.
So what exactly are ignition coils? Speaking dry technical language, then this is a pulse step-up transformer. Its main task is to increase the voltage of the on-board network (usually 12 volts) to a voltage sufficient to breakdown the air gap between the electrodes of the spark plugs. And impulse voltage. The breakdown voltage value ranges from 25 to 35 thousand volts.
Let's take a quick look at the ignition coil design. It is, in principle, typical for all models, there are only minor differences in execution.
As in any transformer, the heart of the coil is a ferromagnetic steel core (17), around which the primary (4) and secondary (5) windings are wound. All this is placed in a housing made of insulating material (2), for safety. The windings are separated by insulating paper (3). The coil body is filled with transformer oil, which is necessary for cooling and insulation. The primary winding is formed by a relatively small number of turns of thick wire. The secondary winding is made of thin wire and can have from 15 to 30 thousand turns.
Now let's look at how the ignition coil works. Perhaps, you remember, back in school, in a physics lesson, they taught the Law of electromagnetic induction. "For anyone closed circuit... ". Let's remember the point. generated electromotive force(EMF) is proportional to the rate of change of the magnetic flux. The operation of the ignition coil is based precisely on this law. 
When a current with a voltage of 12 volts flows through the primary winding, a magnetic field is generated in the coil. In this case, an induced voltage appears in the secondary winding. When the piston passes through the top dead center the primary winding circuit is opened by a breaker. The magnetic field instantly decreasing as a result of this, according to Faraday's law, creates a high voltage pulse in the primary winding. And since the bobbin is a step-up transformer, the voltage in the secondary winding increases even more in proportion to the ratio of the number of turns in the windings. Further, this impulse classical systems By high voltage wires through the distributor is transmitted to the spark plugs. The spark gap is blocked by the discharge and the air-fuel mixture is ignited.
In addition to the classic ignition schemes, there are others. For example, with a two-spark (two-pin) coil. As the name suggests, this coil has two high voltage leads. Two-lead reels are mainly used in two-cylinder engines. They can also be used in multi-cylinder internal combustion engines with an even number of cylinders, it is enough to increase the number of coils. The dual-spark coil delivers a high-voltage pulse to both cylinders simultaneously, with only one of them at the end of the compression stroke. The second spark is blank. The described scheme allows you to simplify the system and abandon the ignition distributor.
Today, individual (plug-in) ignition coils are widely used. They are mounted directly on the spark plug. That is, each engine plug has its own coil. Such a scheme can significantly reduce the size of the system and increase reliability by reducing the number of elements (distributor, high-voltage wires).
How can I check the ignition coil
Despite the fact that the design of the reel, at first glance, is simple, a malfunction of the ignition coil is still possible. The symptoms of defects are similar. The engine starts to work unstably, "troit", there are failures in work. The engine may simply not start. On new vehicles, the CHECK ENGINE light will indicate a malfunction.
Previously, the coil was often checked in the old "grandfather" way. Cranking the engine, they checked for a spark between the candles and the "mass" of the car. IN modern engines such experiences can lead to sad consequences. You can damage not only the ignition coil, but also other sophisticated vehicle electronics.
Consider the most frequent malfunctions ignition coils, symptoms and methods for their diagnosis. For example, the ignition coil gets hot. In principle, the coil should be heated, but not prohibitively. At long-term operation, whether we like it or not, the "aging" of the insulation occurs. And this process is typical not only for bobbins. As a result of the deterioration of the insulating properties of the dielectrics in the coil, the risk of internal short circuit and consequently overheating. If the temperature rises above 150 degrees, then most likely the coil needs to be replaced.
How to check the ignition coil with a multimeter
The question arises: "How to check the ignition coil?". Multimeter ... This is probably the most affordable way.
Let's look at how to ring the ignition coil with a multimeter. It is necessary to alternately check the resistance of the primary and secondary windings. It does not hurt to check the resistance between the terminals of the windings and the case. The resistance of the primary winding should fall in the range from 0.3 to 2 ohms, the secondary - from 6 to 15 kOhm. The resistance between the terminals of the windings and the case should tend to infinity. If the values of the measured winding resistances deviate from the described ranges, an interturn short circuit is possible, but if the winding resistance tends to infinity, this is a sure sign of a wire break in the turn.
What to do if there is no spark from the ignition coil?
You got into the car, turned the ignition key in the lock with the usual movement, the starter diligently turns the engine flywheel and ... And the engine does not start. What to do? Initially, we assume that everything is fine with the fuel supply. Then the reason is banal - there is no spark. Before running after the multimeter, let's decide if it's the coil.
First you need to check all the detachable contacts associated with the formation and transmission of a voltage pulse, if necessary, clean them. Check spark plugs. They must be clean and dry.
If everything is in order, you can try replacing the coil with a known good one. Witchcraft with an oscilloscope, I think, can be left to a car service.
You ask: "How to repair the ignition coil with your own hands?". I will answer - no way. It needs to be replaced. The coil cannot be repaired.
How much does an ignition coil cost? In different ways ... Depending on the brand of car. For example, for the VAZ-1118 you can buy for 900 rubles. Coil price for CHEVROLET Aveo starts from 6 thousand rubles. Rare models, such as the wf72 ignition coil for Porsche, can cost up to $300 and are only available on order.
Conclusion
In conclusion, I want to say, love your four-wheeled horse, keep the ignition system clean, and regular maintenance trust only qualified socialists. And it will serve you faithfully for a long time.
This video shows how to check the ignition coil without equipment:
