Automotive stroboscopic devices STB-1 and "Auto-Iskra"

Why doesn't the candle work?

In addition to electrical reasons - breakage and breakdown, failure or unstable operation of the spark plug can be caused by trivial things. For example, an incorrect gap. We look at the car's operating manual, take the correct feeler gauge to determine the gap and bend or straighten the contact. Another reason is carbon deposits. Carbon deposits, especially black, greasy ones, can be caused by low-quality fuel, improper adjustment of the engine power system - old drivers talk about this phenomenon as “overfilling”. Or, in the worst case, wear of the oil scraper rings. Which is fraught with engine disassembly and repair. The spark plug is cleaned of carbon deposits using various mechanical and chemical methods. The simplest thing is to remove carbon deposits with a metal brush and rags, and additionally clean the electrodes with sandpaper. If the spark plug is clean and the gap is set correctly, we check for electrical problems.

How to identify faults?

Tester for diagnostics of the SZ
It is not so difficult to identify the performance of the SZ on your own - this can be done both by visual inspection and by analyzing the performance of the engine. One of the main symptoms of an SZ failure is non-standard engine operation. In particular, we are talking about the difficult start of the power unit, its unstable operation, in particular at idle speed.

But besides these symptoms, there are many other signs, which are given below:

1. In particular, we are talking about the rotation of the crankshaft. The crankshaft rotates at the required frequency, but the power unit does not start because ignition, i.e., ignition of the air mixture, does not occur in the system.
2. Presence of flashes in the cylinders. If flashes of the air-fuel mixture occur in the cylinders, this can lead to unstable engine operation. In particular, the internal combustion engine will work intermittently.
3. Poor engine starting. In principle, the engine can start, but if the starter stops working, the engine also stops.
4. Increased gasoline consumption. If there is no ignition of the air-fuel mixture, then engine power is either reduced or completely lost. Accordingly, compensation of engine power is carried out as a result of supplying an increased portion of fuel to the cylinders. Ultimately, this leads to excessive fuel consumption.
5. Failure of the catalyst. If the system does not ignite, the air-fuel mixture will not be able to ignite. Fuel that does not ignite will enter the catalyst and oxidize, thus contributing to its failure.
6. Problems starting a cold engine. At the moment when the driver turns the key in the ignition switch, cold SZ can collect condensation, which in itself is a good electrical conductor. If the gap between the SZ electrodes is increased, the breakdown voltage level should be increased. However, at home it is impossible to increase it, since electricity will flow through these same electrodes and ceramic cone.
7. Another, no less important sign is the presence of traces of mechanical damage on the surface of the spark plug. This indicates, if not a complete breakdown, then at least incorrect operation of the SZ, which over time can lead to its failure.
8. Presence of soot and deposits on the SZ electrodes. In addition, if the SZ smells of fuel, this indicates a malfunction of the system itself, as well as the spark plugs.
9. High-voltage cables on the NW can also contribute to the deterioration of engine performance. Especially if these wires are damaged.

Two SZ - with and without plaque

Visual method

As already noted, the simplest diagnostic method is visual. How to check the performance of spark plugs? Here special attention is paid to appearance. The following are photographic examples with different conditions:

1. Normal working condition.
2. Increased fuel consumption.
3. Weak composition of fuel and air.
4. Excessive formation of additives.
5. Oil seals are in poor condition.
6. One of the valves or the partition between the piston rings is broken.
7. The engine was running too long or poor quality fuel was used.
8. The oil burned due to wear and tear of the piston oil rings.

How to check the serviceability of spark plugs? On them we exclude: deformations, chips, various scratches, etc.

If there is soot and burning on each heat cone, then the fuel is supplied evenly and burns out stably. If there is a difference in the amount of carbon deposits, fuel supply is problematic.

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If there is oil deposits on the elements, this is a sign that the engine fuel technology must be restored.

We also exclude dark paths. This is a sign of a damaged glazed coating.

If one or more of their designated signs were detected, this is not yet evidence of complete deterioration. This can only be absolutely verified with equipment.

How to check the performance of spark plugs

The design of most cars allows you to disconnect the ignition elements without much difficulty. This makes the process of checking spark plugs easier.

There are several ways you can carry out this procedure without resorting to the help of specialists:

• "to the sound";
• "to spark";
• using a multimeter;
• using a "gun".

The first two methods are the simplest. Even a novice driver can cope with them. They do not require special tools or skills. Devices designed to carry out such a procedure are also easy to use. If you wish, you can create your own device that performs these functions.

Spark plug

Sound check

Malfunctions in the engine cylinders affect the sounds it makes. If one of the parts does not cope with its functions, the cylinder does not work correctly, and the nature of the sound of the engine changes. This property can be used for diagnostics. You must proceed as follows:

1. Start the engine. Remember the sound it makes.
2. Disconnect the wires from each spark plug (one by one), checking at the same time for any changes. If you disconnect the working spark plug, the unit will make a noise different from the original one.
3. A non-working element can be identified if, when the spark plug is turned off, the sound of the engine does not change.

This is the easiest verification method available to everyone. No tools are needed to carry out such diagnostics. However, the method has a number of disadvantages. The first is to use fuel during the test. The second is the impossibility of establishing the nature of the breakdown and its cause. The method only allows you to identify the malfunction and replace the element.

Additionally, the sound changes are not always clear enough to detect the problem. In some cases, it is quite difficult to notice the difference. Using a spark test, it is easier to detect the problem. A more reliable way: build a stand for checking spark plugs with your own hands.

Checking for spark

The second method is no less simple, but you will have to remove the candle. Therefore, the car owner must have a special key designed to carry out this operation. If not available, it can be purchased at any auto parts store. To check, you must first remove the element. First of all, the wire cap is disconnected from the part. Next, it is removed using a special key. Before proceeding directly to the performance test, it is necessary to carry out certain preparatory work. The surface of the spark plug must be cleaned of deposits, and the gap between the electrodes must be checked using a feeler gauge (you can find out the standard value of this parameter by reading the vehicle’s maintenance manual).

If the gap complies with the regulations, you can begin checking. To do this, you need to connect a high-voltage wire to the unscrewed spark plug and lean the latter against any part of the vehicle made of metal (this creates an electrical contact). After turning on the starter, you need to monitor the spark produced by the spark plug. The absence of a spark is evidence of a faulty part. Red sparks indicate abnormal operation of the element. The working part produces powerful and bright blue sparks.

Multimeter

Using a Multimeter

Despite popular belief among the population, a multimeter is not a device for checking the performance of spark plugs. Its use does not guarantee identification of a non-working element. However, using this device you can check the spark plug for a short circuit inside, as well as the wires going to it.

In order to check for a short circuit , proceed as follows:

1. Unscrew the spark plug.
2. Connect one wire of the device to the input of the element, the second to its thread, that is, the base.
3. Set up the multimeter (resistance – twenty kOhm).

If a contact is detected during the test, the cause of the problem may be a defect in the insulator, which leads to a short circuit. If there is contact, resistance appears, which is shown by the multimeter. At the same time, you can check the resistance of the wires. If this parameter is lower than required, parts need to be replaced.

Piezo gun

Do-it-yourself checking of spark plugs under pressure is carried out using a piezo gun. This is a special stand that allows you to check spark plugs for functionality without unscrewing them from the engine. It looks like a gun with a probe, equipped with a special lamp (serves as an indicator) and a plastic cap containing a core connected to a wire.

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Before starting diagnostics, it is necessary to thoroughly clean the part to avoid incorrect results. After this, the high-voltage wire is removed from the element, in its place a plastic cap is installed. The tip of the gun should rest against the cylinder head. After several pulls on the trigger of the gun, its indicator lamp should flash. This is a sign that the part is working. If this does not happen, the element must be replaced.

A small generator is hidden under the body of the gun, which is the main element that allows you to check the performance of the spark plug. The advantage of the method is the ability to check without starting the engine and wasting fuel. The device is notable for its low cost (for example, the price of the “TEST-M” model ranges between two hundred rubles).

Piezoelectric element from a lighter

Tags: spark plug test bench

Comments 42

It’s a good thing, it will come in handy around the house. I want to make myself such a stand. 1-ignition coil only from a contactless system, or will a regular one do? 2-cooler, some kind of special one? I have one - how do I know if it’s him or not?

In the photo you can see the trimming resistors on the device, but I didn’t even see it in the diagram, where you can look in more detail, the diagram and in general the dimensions of the camera, etc., if it doesn’t bother you. :)

Of course, I won’t say anything new, but there is a banal test for spark plugs that looks like a gun without pressure based on the piezo principle. Lighters, if the candle is a ram, then it’s clearly visible, and it’s advisable to change it based on mileage...

Those are toys. It's just a matter of pressure. In appearance, the working spark plug is without pressure, but under pressure it begins to “sew” in all directions, along and through the insulator; in XX mode it can work normally, but in 6000 rpm mode there can also be breakdowns.

It's clear. But I don’t remember that this happened to me during a planned replacement of spark plugs, and if something goes wrong, I buy new ones just in case, of course I understand if it’s iridium, or just V8, but in any case, it’s not that much money

Although spark plugs are consumables, they can travel 30,000 and work, or they can travel 3,000 and stop working. And if you just take your car and change it, then how can you explain to the client at the service center that his spark plugs died after 2-3 thousand miles? This stand is needed for service first and foremost. In any case, such a stand is a direct way to test candles; the rest are still indirect.

Well, for service, yes, at home I have enough of a “pistol”

What is this for?! On my V8, I check the spark plugs like this: 1) I remove the spark plug caps from the spark plugs (I don’t unscrew the spark plugs!) 2) I measure the resistance relative to the housing and the top contact of the spark plug with a 1000-volt megometer. If the resistance is very high, then the spark plug is in excellent condition. Well, if not, then replace it, sandblast it, burn it, etc. and so on. It depends on the circumstances.

Note: There are spark plugs with a continuous central electrode and with a discontinuous one.

Factory product

Factory made tester.
The factory device for testing spark plugs under pressure has the following main components:

• a pistol-shaped body equipped with a special tip that acts as a probe;
• indicator light;
• a plastic cap containing a core inside connected to a wire;
• There is a small generator located inside the device, its purpose is to diagnose the performance of the SZ.

When checking the serviceability of the SZ using the device described above, there is no need to start the engine - this allows you to save fuel mixture consumption.

The performance of the SZ is checked in this way:

• inspect the SZ, if there are external defects (carbon formation, damage to the integrity of the spark plug body, damage to the contacts), replace the products with new ones;
• disconnect the high-voltage wire, install the plastic cap of the measuring device in its place;
• rest the tip of the “gun” against the cylinder head;
• Press the button of the measuring device several times, while watching the indicator light; the presence of flashes on it indicates the serviceability of the diagnosed SZ.

Please note: the absence of sparking during diagnostics indicates a malfunction of the tested spark plug.

The main drawback of the device is the measurement error; it is impossible to judge by the presence of a spark that the spark plug is 100% serviceable: the pressure created by the “gun” differs from the pressure parameter acting inside the engine. The generated spark may not have enough power to ensure normal operating characteristics of the power unit.

How to make a device for testing spark plugs under pressure with your own hands

To assemble such a device, you need to prepare the following:

•two syringes: one 20 ml and one smaller volume, which will be used for applying glue;

•goujon: corresponding to the diameter of the candle;

•glue.

When everything you need is already at hand, we begin to manufacture the device. To do this we do the following:

•cut off the nose of the syringe;

•apply glue to the resulting cut;

•install a threaded bushing (goujon); It is better to insulate the fastening with sealant. We check the part as follows: screw it into the threaded bushing, then connect the high-voltage wire to it. The element body is connected to ground. Then we start the engine. Using a syringe, we carry out a pressure test - this means you need to press on its piston. If the spark is weak or completely absent, then we change the part.

As you can see, checking the performance of a spark plug is a simple matter even for a novice car enthusiast. This can be done either with the help of tools that are available in the market or with a homemade tester. It is necessary to take into account that the pressure level obtained from a home-made device may not coincide with the indicator that is formed when the spark plug operates during actual operation of the car.

Even if it is impossible to detect minor problems in the operation of spark plugs with the help of such devices, they will help identify a spark plug that does not work at all.

Why is this device useful?

A device for checking spark plugs with your own hands can be easily made even by a novice motorist. Having checked the ignition elements using this device, you can consider the whole picture of their operation, namely the following results: 1) Spark power. Its color can always tell the car owner whether the spark is capable of igniting the fuel mixture. Strong sparks are white and blue, weak sparks are pink. It may also happen that there will be no spark at all. 2) How the spark behaves at different speeds. A do-it-yourself spark plug tester diagnoses the operation of the electrodes under pressure, while it recreates the lowest and highest speeds. 3) The device can be used as a candle cleaning tool. If the spark plug is made with electrodes made of precious metals, then to clean the spark plugs you only need to get a powerful spark. Since there is no fuel to ignite, no additional carbon deposits are applied to the electrodes. In other words, the surface being cleaned receives a charge from a powerful spark - under conditions of high pressure, it burns carbon deposits on the surface.

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Checking with a piezoelectric tester

Automotive stores sell a special piezoelectric tester (piezo gun), with which you can check the spark. Using such a device is simple: you just need to insert the candle into the device and press the button. A working spark plug fixed in the gun will produce a spark. You don’t have to buy such a spark gap, but make it yourself using a lighter. The end of the wire coming from the piezoelectric block must be connected to the contact head, and the block itself with the button must be pressed against the spark plug body. The homemade arrester is ready. If a spark does not jump when you press the button, then the spark plug is faulty.

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Error

The main disadvantage of the described testing methods, carried out in the open air, is the difference in pressure (atmospheric and working), as a result of which even a faulty spark plug, when tested with a tester, can give a spark, since in an engine cylinder under excess pressure, more voltage is required to form a spark than in normal ones conditions. That is why such methods cannot guarantee 100% accuracy of the result.

A special testing stand, available in auto repair shops, simulates work under pressure in the cylinder, bringing diagnostic conditions closer to real ones. However, you can make such a device yourself.

Device option for testing, checking spark plugs under pressure

There is also another type of homemade spark plug tester. One folk craftsman assembled such a device with his own hands - as he himself said, not to make it cheaper, but to create a device with his own hands - and he did it perfectly. This tester is made in the form of a box, and also consists of an ignition coil, a switch and a Hall sensor emulator, and a compressor for inflating the wheels inside this box. At the top there is a pressure gauge, which allows you to control the pressure in the chamber, as well as the chamber itself in which the candle is placed. A cooler is installed to purify the housing in case of checking a large number of spark plugs.

On the right side there is a fitting, including a tap, to which air can flow from an external compressor.

A battery is used to power the device. Protection against polarity reversal is provided.

A turner worked on the chamber - he turned out a cylinder into which the spark plug should be screwed. The chamber has a spool for bleeding air, in the lower part there is a fitting that supplies air, in the upper part there is a window to monitor the formation of a spark. There is a small mirror installed inside the chamber, which makes it possible to see the end of the spark plug and check whether a breakdown has formed on the insulator of the central electrode. A spark appears only between the central and side electrodes, even if there is pressure. An abnormal spark can be seen here. The spark plug worked normally, but after the pressure in the chamber increased to 6 bar, the spark stopped appearing between the central and side electrodes, but appeared under the skirt of the spark plug. That is, the spark plug generates a spark, but it will not ignite the fuel mixture. In this case, the spark plug works well at idle, but if there is a load, misfires will begin. You can view all the other information in the video. The device itself is described in detail here, how to make the device, and how it works is shown.

Assembling a spark plug tester

The device is made on the basis of any kitchen electric lighter. When purchasing it, you may mistakenly take a gas lighter. You need one that does not burn, but only generates a spark for ignition and is powered by batteries. The lighter body is disassembled. You need to remove the metal rod coming out of it; it will no longer be needed. The wires connected to it are disconnected.

There are 2 holes made in the upper front half of the body. A large clamp is screwed through them onto the screws. It must be positioned in the same way that the removed rod was secured.

A wire from a lighter coil is connected to the crocodile. It will also require drilling or burning a thin hole in the housing. The second wire needs to be brought out from the side. For this, a separate hole is drilled. To make it wear out less, it should be protected from fracture with heat shrink. A small clip is attached to the end of the wire. Most likely, the length of the existing wiring will not be enough, then before installing the heat shrink and clamp, you will have to extend it with a small section of 15 cm.

The device body is assembled and 2 batteries are installed in it. For aesthetics, you can cut the insulator removed from the large clamp lengthwise. The resulting segment is glued to the bare crocodile handle, screwed to the body.

To test a candle, it is clamped in a large crocodile on the threaded part. A small clip is placed on the contact tip. After pressing the button, the high-voltage converter delivers a discharge to the spark plug. If it is working, then a striking spark should appear in its gap between the side and central electrodes. A spark plug that is not working will not have a spark.

Checking the ignition coil

To check the ignition coil, there is one popular method that should not be used. It is often used by illiterate car owners and non-professional “garage” workshop workers. The test involves unscrewing the spark plug from the engine body, inserting it into a high-voltage wire and pressing it against the engine body. Then the engine is started - a bluish light flashes between the housing and the spark plug, which is a spark. A significant disadvantage of this method is the possibility of receiving a high-voltage electric shock, as well as burning a completely serviceable coil or its control keys in the electronic engine control unit.

To properly and fully check the ignition coil, you need to contact a car service center. If you want to do everything yourself, then you need to make special devices - spark gaps, since testing with a regular spark plug is not very effective due to the fact that to break through its spark gap in air, you need much less voltage than to break through the same gap in the engine cylinder, where the operating pressure is 6 - 10 Atm. To create similar conditions, we need to increase the size of the spark gap several times.

To test the coils of contact ignition systems, a spark gap can be made from any motorcycle spark plug with a low central insulator and short thread, simply by removing the side electrode. In this case, we obtain a spark gap of about 3 mm, quite sufficient to check the operation of the coil. For convenience, you can use a regular screw clamp to attach an electric alligator clip, sold in any auto store, to the spark plug thread and use this clip to attach the spark plug to the engine ground when checking the coil, in any accessible place.

You should pay attention to the tightness of ignition coils that use transformer oil. Oil leaks on such coils, as a rule, indicate that it has boiled as a result of a breakdown or short circuit of the turns of a high-voltage transformer.

To test modern dual ignition coils, you need a spark gap of 8-10 mm. To obtain a spark gap with such a gap, you will have to cut the thread of a regular car spark plug with a high insulator of the central electrode. The thread is cut around the insulator with a hacksaw or grinder, leaving approximately 5 mm. the hexagon has spark plugs. It is enough to screw a screw onto this remaining thread to restore the spark plug holes in the “head” of the engine. You can also buy a screwdriver at a car dealership. A spark gap of this design will have a required gap of about 9 mm. from the screw thread to the central electrode of the spark plug. Before checking, the coil should be removed from the machine and inspected for breakdowns in the housing insulation.

To do without an assistant turning the engine with the starter when checking the coil from the driver’s seat, you can make a simple switch. To make it, you need to buy about three meters of wire, with a cross-section of 2.5 - 3 mm, three internal terminals (“female”), any switch (for example, a VAZ 2110 light switch) and the above-mentioned alligator clip. We cut the wire in half. We put and crimp the internal terminals on the two ends of one piece of wire, on one of the ends of the remaining piece of wire too, and on the remaining end we put on and crimp the alligator clip. We find a pair of contacts on the switch that close together when it is turned on and put the ends of both parts of the wire with internal terminals on them. Now we put the end of the wire with the alligator clip on the positive terminal of the battery, and the remaining end of the wire with the internal terminal on the contact of the starter solenoid relay, having previously removed the standard wire coming from the ignition switch. After this, by pressing the button, you can turn on the starter from under the hood, without an assistant, and check the coil, having first turned on the ignition.

When checking reels, do not forget about safety precautions. You can turn the engine with the starter only by first turning on neutral at the gearbox and without touching the high-voltage wires and coils with your hands. On injection engines, when checking the ignition system, it is advisable to disconnect the injector harness connector to prevent the engine from starting, or from washing off the oil film from the cylinder walls with fuel flowing through the operating injectors in the absence of a spark. On carburetor engines, when checking the coil, you need to fully open both throttle valves to purge the cylinders and prevent the spark plugs from filling with gasoline. This can be done from under the hood by pressing the throttle drive cable (rod). The air damper must be completely open.

The spark on the spark gaps should be bright and blue. If the spark is weak and red, the coil needs to be replaced.

Using this method, you can independently check the serviceability of the ignition coil and high-voltage wires not at 100%. Only the presence of a normal spark and the absence of obvious breakdowns are checked. A more complete check of the ignition system can only be done if you have a motor tester (oscilloscope) and the ability to use it.

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