The spark disappears on the VAZ 2109 (carburetor): possible malfunctions and their elimination

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

The ignition system of the VAZ 2109 carburetor engine is quite simple, so there are practically no critical malfunctions. And those problems that sometimes happen, you can fix it yourself without any problems. In this article, we will talk about the reasons why the spark disappears on the VAZ 2109 (carburetor), and also consider methods for eliminating them.

Signs of malfunction

Faults in the ignition system are manifested by unstable operation of the engine or its complete stop and inability to start. In the first case, the engine power indicators are significantly reduced, fuel consumption increases, the exhaust color changes, vibration appears.

Such symptoms may indicate that fuel is not being burned in one of the combustion chambers, or that a spark formed on the electrodes of one or more candles is not able to ignite it. In the second case, when the engine does not start at all, most likely there is a malfunction of one of the main elements of the system. It is this that most often leads to the fact that the spark disappears on the VAZ 2109 (carburetor).

Systemcarburetor ignition

All "nines" from the factory are equipped with a non-contact ignition system. Structurally, it consists of the following elements:

• ignition switch;
• high voltage coils;
• switch;
• Ignition distributor with Hall sensor;
• four high voltage wires;
• spark plugs.

If any of the first four elements fails, the ignition system stops working and the engine cannot be started. You can correct the situation by diagnosing and eliminating the breakdown.

How the ignition system of a carburetor VAZ 2109 works

To understand why the spark disappears on the VAZ 2109 (carburetor), let's look at how its ignition system works. Let's start from the very beginning - with the castle. When the driver inserts and turns the key in the ignition, electrical current flows from the battery to the coil. It performs the function of a transformer, converting standard 12 V to 25000-30000 V. From the coil, high voltage current is supplied to the ignition distributor, driven by the engine camshaft, and from it through high-voltage wires to candles. The commutator is involved in this whole process, providing the formation of current pulses of the desired value in the coil, as well as stabilizing the voltage in the system.

High voltage wires

So, if you suspect that the spark is disappearing on the VAZ 2109 (carburetor), first of all, you should check the integrityand fastening of high-voltage wires. To do this, lift the hood and conduct a visual inspection of the conductors coming from the coil to the ignition distributor, as well as from it to the candles. Check that they are securely fastened, that there are no dirt and moisture on their contacts.

To determine if the armored wires are working, they can be checked using a car tester turned on in ohmmeter mode. The resistance of each of them, depending on the brand and manufacturer, should be from 3.5 to 10 kOhm. If it is higher, you can be sure that the spark on the VAZ 2109 candle has disappeared precisely for this reason. You need to change high-voltage wires as a set.

Candles

In the carburetor VAZ 2109, spark plugs fail more often than other elements of the system. This is due to the poor quality of the fuel, and to the incorrect setting of the fuel supply, and to the candles themselves. In addition to the fact that there are a lot of fakes on the auto parts market, not every owner of the "nine" bothers with the glow number or the gaps between the electrodes provided for by the manufacturer's recommendations. So it turns out that having bought seemingly new and branded candles, we have unstable idling or tripling altogether. In the future, these seemingly minor malfunctions can lead to more serious problems.

Ignition VAZ 2109 provides for four spark plugs: one per cylinder. They are checked one by one. First, one of them is unscrewed, visually inspected for integrityceramic insulator, the state of the electrodes and the size of the gap between them. If with a candle, at first glance, everything is in order, you need to determine its performance. To do this, they put on a cap of a high-voltage wire and attach it to the ground with a skirt. Next, you need to attract an assistant and ask him to start the engine. When the starter starts to rotate the crankshaft, a steady blue or blue spark should jump between the electrodes. If it has a different hue (red, greenish), this may indicate a possible breakdown of the insulator or insufficiently high voltage. If there is no spark at all, most likely the candle is out of order. But other faults cannot be ruled out here. That is why it is necessary to check all spark plugs. In the case when only one of them does not work, try replacing it with a known working one. But if there is no spark at all candles, the problem needs to be looked for deeper.

Ignition switch

The next step in the diagnosis is to check the ignition switch. To do this, we need the same car tester, but already turned on in voltmeter mode. Connect the positive probe of the device to the “+ B” terminal on the ignition coil, and short the negative probe to ground. Next, turn on the ignition and look at the tester readings. Lack of voltage is evidence that the contact group of the lock is faulty. In this case, the repair (VAZ 2109) provides for its replacement.

Coil

As we have already said, a coil is a transformer that generates a high voltage current. She hastwo windings that are not insured against a short circuit or open circuit. If 2109 (carburetor) does not start, a coil check is required. Moreover, it is quite simple to determine its performance. To do this, with the engine off, remove the central high-voltage wire coming from the coil from the cover of the ignition distributor. It has a protective cap. You need to connect a spark plug to it and attach it with a skirt to the ground. After that, ask the assistant to turn on the ignition and scroll the starter. If the coil is working, a spark will appear between the electrodes of the candle. A faulty transformer cannot boast of this.

Important: in no case do not hold the candle with your hand or pliers without insulating the handles. The voltage given out by the coil reaches several tens of thousands of volts, and even considering the relatively small current, there is a threat of damage to it. You should also not check for a spark without a candle, i.e. between live wire and ground. This will disable the switch.

Ignition distributor

After the coil has been checked and the diagnostic results show that it is in good working order, we proceed to the ignition distributor (distributor). Disconnect the high-voltage wires from its cover and unscrew the two screws securing it. Remove the cover and inspect it for integrity. Pay attention to the condition of the carbon contacts and the distributor slider. In the event of a malfunction, the cover (assembly) will need to be replaced.

Hall sensor is used to transmit control and correctivepulses to the switch depending on the number of engine revolutions. It is installed inside the ignition distributor, but in order to check it, it is not necessary to disassemble this element. All you need is a car tester or multimeter set to voltmeter mode and a couple of pins.

Find the green and black and white wires in the connecting block connected to the distributor. This is the output of the sensor. On these wires, you need to pierce the insulation with pins, and connect the probes of the measuring device to them. Have an assistant turn the engine crankshaft slowly by hand.

This can be done either with a screwdriver, pushing the flywheel through the hatch in the clutch housing, or with a wrench thrown over the crankshaft pulley nut.

If the Hall sensor is working, the device will show voltage surges from 0.4 to 12 V during rotation. If it has become unusable, the device will be “silent”. In this case, the repair (VAZ 2109) will be limited to replacing the sensor.

Switch

Finally, let's talk about the switch. Its function is to form the correct electrical impulses in the primary winding of the coil based on data received from the Hall sensor. In addition, it limits the maximum current and voltage in accordance with the parameters of the on-board network.

Checking the switch without special equipment is quite difficult. The easiest way is to connect a known-good element and check the operation of the ignition system. Some owners of VAZs, taught by bitter experience, often eventhey carry a spare switch with them, and in which case they simply put it in the place of the failed one.