Flooded, wet spark plugs after starting - this situation is familiar to almost all owners of cars with carburetor engines. At the same time, starting the engine with flooded spark plugs is very problematic. If at this moment the spark plugs are unscrewed, they will be wet, filled with gasoline, which in most cases is a consequence of a very strong enrichment of the fuel mixture in the start mode.

Naturally, there can be no question of any normal spark in such a situation. This situation can occur both when starting a cold engine and a hot one. Consider the reasons for flooding spark plugs using the example of a carburetor engine 21083 of cars VAZ 21083, 21093, 21099.

A list of the main causes of spark plug flooding

- Start of a hot engine on "suction".

Starting a warmed-up engine with the "suction" handle extended towards itself and a closed air damper will lead to a strong enrichment of the fuel mixture in this mode and, as a consequence, flooding of candles.

air damper open during hot start

- The carburetor starter is faulty or not adjusted.

To a greater extent, the problem concerns a cold start. It is necessary that the starting clearances "A" and "B" were set exactly, that is, there was a starting device. In addition, the PU diaphragm mechanism must have an intact, non-punctured diaphragm and have a sealed housing. Otherwise, when starting a cold engine, the carburetor air damper will not open slightly to a certain angle (this is the whole point of the PU operation), forcibly depleting the fuel mixture with a portion of additional air. The absence of such a slight opening will lead to excessive enrichment of the fuel mixture in the cold start mode and the candles will flood.

visible elements of the Solex carburetor starting system

- Defective spark plugs.

"Punched" ones, having black carbon deposits, with an incorrect gap between the electrodes of the spark plugs, will not be able to ignite the rich fuel mixture entering the cylinders in the start mode and will be immediately filled with gasoline. It is advisable to have a spare set of candles in order to quickly change them if necessary. can be filled with fuel, both during cold and hot start.

- Defective needle shut-off valve in the carburetor float chamber.

The needle valve of the float chamber can be leaking (either from wear or from a defect) and allow excess fuel to pass into the float chamber, which in turn again leads to an over-enrichment of the fuel mixture in the start mode. Moreover, due to a faulty needle valve, the candles can be filled both during a cold start and during a hot one. Very often, a leaky valve gives out a constant smell of gasoline in the engine compartment and fuel leaks on the carburetor. A needle valve is recommended and replaced with a new one if necessary.

checking the needle stop valve of the Solex carburetor

- Pumps the gasoline pump.

The gas pump can pump due to an incorrectly adjusted drive. The excess fuel pressure created by it on the needle valve will lead to fuel overflow and an increase in its level in the float chamber, which in turn will entail excessive enrichment of the fuel mixture. It needs a drive.

protrusion of the pusher required for the correct operation of the fuel pump

- GDS air jets are clogged.

GDS air jets supply air to the fuel mixture, allowing it to have the correct ratio (gasoline / air) required for a confident engine start. A decrease in the amount of incoming air or its absence at all due to clogged air nozzles leads to a strong re-enrichment of the fuel mixture and the subsequent flooding of candles. Cm. .

Solex carburetor GDS air jets

- Poor volatility of fuel vapors in frost.

In severe frost, the volatility of fuel (fuel vapors ignite at start-up) is greatly reduced. The fuel settles on the walls of the intake manifold and, getting into the combustion chambers, fills the candles. It is recommended to press the gas pedal several times before starting and wait 15-20 seconds and only then start the engine. Some drivers spill boiling water on the outside of the intake manifold and only then start the car engine.

Notes and additions

- If the spark plugs are filled with fuel, and you still need to start the engine right now, and without troubleshooting, then it is recommended to do the following. We drown the "suction", press the gas pedal all the way down and turn the engine with the starter for a few seconds. In this case, the throttle valves of both chambers of the carburetor will be fully open, the mixing chambers are subjected to strong blowing, and the candles will dry quickly. You can repeat this "purge" a couple of times at intervals of a minute (if the battery allows) and then try to start the engine again.

Imagine a situation that can often be observed in winter: a driver, having left his car in the garage, cannot start the engine in the morning, even with a charged battery. Such cases are typical for winter, since at low temperatures the processes in the motor are almost unpredictable. The fuel may not ignite completely, and then the candles are flooded with gasoline, despite the fact that a spark is formed. Let's say the mixture is too rich and the compression is insufficient. Then, in any case, the combustion process cannot go on. The reasons for such phenomena have long been known, and how to deal with them is described further.

Why is this happening

The operation of injection engines, where the mixture is formed in the volume of the fuel rail, is always controlled by a special controller. The control unit in question is also called "ECU":

The injection motor will not start without the ECU

The program installed in the unit's memory always determines for how many milliseconds each of the nozzles should open. The longer the nozzle is open, the richer the mixture is formed. And in winter, at low temperatures, the controller seeks to enrich the mixture to the maximum. And then the following happens:

• The concentration of gasoline in the mixture is at its maximum, but the temperature of the fuel and air remains lower than typical for the summer period;
• Compression in the cylinder, due to worn parts, may be insufficient;
• If there is carbon deposits on the plug contacts, sparking does not occur as the developers expected.

In sum, these three factors lead to the following result: the fuel does not burn, but gets on the spark plug contacts. As a result, sparking stops, and then, when you try to start the engine, gasoline is pumped into the cylinder. Then, at a certain point, the fuel detonates.

When the candles are filled with fuel, you can observe the same symptoms on any car. Starting during the operation of the starter does not occur, but the driver will hear the pops characteristic of such cases (detonation result).

Causes of the problem and set of solutions

If the spark plugs are really flooded with gasoline when starting the engine, then you need to check how well the spark is forming in the engine. You may have to sequentially unscrew each of the candles, having previously removed the high-voltage connectors. In this case, the ignition must be turned off. It is advisable to disconnect one of the battery terminals too.

Use a box spanner to disassemble

What to check:

• There should be no carbon deposits on the plug contacts;
• The distance between the contacts must correspond to the "passport value".

The bad news is that the reason for the unstable formation of a spark can be the poor quality of the wiring, and any malfunction in the ignition control system. Sometimes finding the cause takes longer than fixing the defect. In such cases, it is difficult to do without the help of professionals. Don't overestimate your strength.

By the way, you can try to reason logically. The controller adjusts the concentration of the mixture based on the air temperature values. And these values \u200b\u200bare determined according to the readings of the only sensor - DTOZH.

Any temperature sensor is a thermistor

This is, of course, the coolant temperature sensor.

The readings of the antifreeze temperature sensor may actually be underestimated. Then don't be surprised if the mixture is too rich in fuel. The recommendation for fixing the problem looks trivial. The sensor needs to be replaced.

Note that in modern engines, to calculate the concentration of the mixture, not one temperature sensor is used, but several. An air heating sensor installed in the intake manifold can also be used. But the presence of engine oil in the manifold is not uncommon. And imagine what will happen if liquid gets on the body of such a sensor.

The controller program is designed so that the main source of information about the air temperature is the DTOZH sensor. This is also true for modern engines that use many temperature control elements.

If the candles are already filled, how to proceed

If there is a suspicion that at least in one of the cylinders the spark plug is filled with gasoline, proceed as follows:

1. They stop the work of the starter, turn off the wiring, dismantle the spark plug;
2. Close the candle well so that dust does not get into it. The shaft is rotated with a starter by 10-15 revolutions;
3. The candle is dried and replaced.

1. The spark plugs can be dried in the engine itself before performing “step 1” above. When the starter is working, the gas pedal is recessed "to the floor" and air is sucked in through the ramp;
2. To remove carbon deposits, you can use a metal brush. A regular toothbrush will work too;
3. If the compression in the cylinder is insufficient, it will be useless to change or clean the plugs. Only major repairs will help here.

When replacing or reinstalling candles, it is advisable not to overtighten their fastening. At the same time, a plug that is not screwed in will cause damage to all engine systems.

The advantage of a good car is its trouble-free operation. However, some cars create problems for their owners when starting the engine. The cause of the problem does not always lie in a discharged battery or a lack of fuel in the tank. Candles are often the culprit in gasoline engines.

Excessive amount of fuel does not allow spark formation in a timely manner. This results in an imbalance in the cycles. At the same time, not all novice motorists understand why they flood spark plugs, although there may be several reasons.

Ignition problems often occur during the cold season. With an open storage method, a frosty morning can bring trouble to the car owner.

It will be possible to identify the problem by some indirect signs:

• there is rotation of the crankshaft by the starter, but there is no seizure;
• a distinct smell of gasoline spreads through the exhaust system, which is heard especially during the rotation of the starter;
• unscrewing the candles, you can notice the remains of fuel not only on the electrodes, but also on the threads, and the underside is covered with dark carbon deposits.

It is important to know that the injector fills the candles with gasoline in frost much less often than carburetor counterparts do.

There are certain features when filling candles in a car with an injection power supply system and a carburetor one, but in both cases, the common thing is the presence of the fact that fuel has entered the chamber and the absence of its ignition. In this case, the contacts are in the liquid, sparking does not occur, and further normal operation of the motor becomes impossible.

Wet spark plugs: causes

Based on the practice of most motorists, the following circumstances are the predecessor of flooding:

• Filling with low quality fuel. In winter, an important factor is the purity of gasoline from unwanted components that have a direct impact on the quality of ignition. An excessive amount of paraffins minimizes the ease of starting in such cold conditions. Do not forget about the presence of condensate in the tank, collecting from temperature extremes.
• Breakdown of the ignition system. Difficulties are created not only by candles, but also by the work of high-voltage wiring. Old, long-used candles have distorted gaps, there are defects on the body or on the electrodes. The consequence is the absence of a spark. It is important to monitor the performance of the system as a whole.
• Low battery power. It is worth waiting for problems when the charge level is low - by 40-50%. When the ambient temperature drops, not every battery is able to work, giving the maximum power sufficient to rotate the starter and the full functioning of the ignition system. The result is the supply of fuel to the cylinders, however, ignition is not carried out, the spark plug electrodes are filled.

In reality, the electronic control unit takes into account the external temperature, the current heating of the engine, the mass of oxygen in the air sent to the engine, etc. A command is sent to open the injectors, which enriches the mixture with fuel, facilitating a cold start. At primary idle speed, the automation helps stable operation / starting of the power plant.

Such events can negatively affect engines with significant wear of the cylinder-piston group. Inside there will be a small compression, at the lower permissible limit. An additional negative will be a slightly shrunken battery, thick oil and soot deposits on the contacts of the candles. As a result, the consequences will be noticeable:

• low quality gasoline enters through the nozzles, which evaporates poorly due to the low ambient temperature;
• the crankshaft lowered into grease is hardly rotated by the starter;
• in a cooled engine, cold parts are not expanded, and due to the low temperature, gaps in the cylinder-piston group are noticeable and compression is reduced;
• a weak spark is generated due to contamination of the spark plug contacts with soot.

Even some of the problems from this set can lead to difficulty in starting the motor or starting intermittently. Accordingly, most of the listed parameters will have to be monitored.

It is important to know that if one of the candles is poured regularly, then it is necessary to check the state of compression in a particular cylinder.

Filling in the presence of a spark and rotation of the starter

Experienced motorists are faced with situations where a spark appears, the starter rotates, but the lower part of the candles is filled with gasoline. Do not be deceived by the presence of a fire, since this event can occur irregularly under pressure, and can be lost during the operation of the motor.

The cause of the event is the excessive pressure in the cylinders. It will be possible to identify the event and the factors driving it when monitoring a car on a stand simulating a combustion chamber.

We recommend that you pay attention to the valve timing, because their failure will be the cause of wet electrodes... In injection internal combustion engines, motorists must check the operation of the bypass valve located on the fuel rail. If you eliminate its problems, you will need to find out the gasoline pressure in the rail, because the manufacturer regulates this parameter. Sharp fluctuations and going beyond the specified interval (larger / smaller sides) can block the start of the internal combustion engine or stimulate the flooding of contacts for spark ignition.

Diagnostics will need to be carried out for sensors of the electronic control system and for injectors. An example of a failure is sending invalid data from the coolant temperature sensor. In such a situation, the control unit unreasonably over-enriches the fuel mixture. Much less often, the culprit of incorrect impulses is a failed electronic control unit or a failure of its software. In this case, problems will manifest themselves not only with the ignition.

Oil problems

The contacts of the spark plugs can be filled not only with fuel, but also with oil. The facts are found on both carburetor and injection engines. One or more cylinders may fail.

When the candles are thrown with oil, the first step is to determine whether the filling is from the bottom or from the top. This is noticeable by which part of the candle is more dirty. If lubricant accumulates inside the spark plug well, it is necessary to check the tightness of the cover valve gasket, as well as the seals located nearby.

If there is visible black carbon deposits on the screwed-out plug in the area of \u200b\u200bthe threads, then oil seeps out of the well. Accordingly, pouring is carried out from below. It will be necessary to measure the compression in the cylinders, because the chance of failure of the oil scraper rings is significantly increased. Events can happen to them:

• a crack has appeared;
• bedding occurred;
• the mating surfaces are worn out.

It can also cause wear on the liner or cylinder block wall. Additionally, we recommend checking the condition of the directional valves, valve stem seals, possible cracks in the block head through which grease penetrates.

Dealing with the consequences

Let's figure out what to do if the candles are flooded. If the motorist is sure that this has happened, then it is worth drying them in one of the selected ways. Most operating instructions for machines with an injection fuel system recommend immediately unscrewing them from the socket with a candle wrench.

At the next stage, dry the engine by scrolling the starter without candles for about 10 seconds. After drying, we return the spark arresters to their nests and try to start in normal mode.

It is allowed to start the engine with the cylinder purge option when the candles are filled. In many situations, this option will make it possible to start the power plant without additional removal of parts. The purging of the cylinders in the injection engines is carried out by fully pressing the accelerator pedal during start and cranking the starter for 10 seconds. Then let go of the pedal and try to start up classically.

It is important to understand that by depressing the gas pedal during purging, the driver opens the maximum throttle valve, which stimulates maximum air penetration into the cylinders and ensures drying of wet surfaces.

Even after purging, the engine may not start in some cases. Then you will have to dry the candles, first unscrewing and pre-cleaning them from carbon deposits. You will need a medium-hard brush. To remove moisture, a building hair dryer or oven is suitable, after which control the gap between the electrodes.

After such operations, it is worth purchasing a new set of candles, since the resource of the old ones is significantly reduced after annealing. The replacement is usually carried out after 15-25 thousand km of run, regardless of the external state... With frequent pouring, it is necessary to get rid of the cause that causes it, and not the consequences.

The car does not start the first time, and from the second and third attempts to start it becomes more and more problematic? In a cold winter, after a frosty night, this situation is quite common. And, as a rule, it is not the lack of fuel, the dead battery, or the starter that is to blame.

The culprits are car candles, designed to form a spark discharge, which for some reason stopped giving a spark. "Are the candles flooded?" - sarcastically ask neighbors in the parking lot, who managed to start the car the first time. So what does it mean to fill the spark plugs?

Let's consider the process of starting the engine theoretically. Starter starts the car engine. This is an electric motor that spins the engine.

It is he who starts the car engine - starter

The starter motor drives the intake valves that feed into the combustion chamber. The candle at this time sends a spark from the ignition coil through high-voltage wires, from which the fuel assembly ignites. It turns out a kind of microexplosion, from which the engine is started, the valve pistons and all other mechanisms and units of the car are set in motion in a chain. If somewhere in this area there is a malfunction, and fuel consumption will increase.

Passport data on fuel consumption of Lifan cars

Who gave the candles a "shower"

A good starter motor, powerful battery and adequate ambient temperature are required for standard system startup. But frosty weather at temperatures below -15 degrees cannot be called adequate even for a person who has just left a warm house. It is too cold for the fuel-air mixture: gasoline does not mix well with air, which contains a lot of oxygen in cold weather.

At a temperature of -30 degrees, the mixture refuses to mix at all. And the more oxygen in the air, the more gasoline is required. And the car electronics issues a command to the injectors: more fuel! Gasoline enters the combustion chamber, the battery "on its last gasp" tries to rotate the starter, create compression in the cylinders, and even give energy to generate a spark, flash the ignition coils.

Petrol!

If the compression was sufficient, the smallest spark would suffice, but usually not enough. And the injectors continue to pour gasoline. With each revolution of the engine, more and more gasoline enters the combustion chamber, everything around is filled with it. And candles, having got "under the gasoline shower", are no longer capable of sparking.

Flood provocateurs

Several factors can provoke candle flooding. These include an extremely worn-out engine: its pistons are not able to create the necessary pressure.

The pistons of this engine from Lifan Smiley could no longer start the engine in frost

Therefore, the engine will not start in the cold. Candles are also poured in cars with an old carburetor. Although their injection system is considered simple, it is outdated. If the carburetor is incorrectly adjusted, then it pours fuel into the chamber, and floods the candles in winter. Moreover, if the car does not start, the carburetor continues to supply fuel as if it had started. The carburetor has no "sense of proportion".

Carburetor and injection control system

Therefore, before the onset of cold weather, the carburetor needs to be adjusted. Cars with a fuel injection system are also not distinguished by their courtesy in dealing with spark plugs. The on-board computer in cold weather gives the injectors a command to supply more fuel to the air mixture, but with a weak battery, the spark is also not enough to ignite the fuel, as a result, the candles are filled. And although special sensors monitor the fuel supply and the engine at the injector, the car may still not start. If you cannot start the engine the first time, you need to wait and try again.

Low-quality gasoline and oil

Poor-quality gasoline and oil are also provocateurs of filling candles.

And if the situation with filling spark plugs is repeated almost every morning, and even in not very cold weather, then you should pay attention to the quality of the candles themselves and the spark plug wires. Experienced motorists, assuming what may happen in the winter period of time, prepare for it in advance. As a rule, a powerful battery is installed and over time it is necessary to monitor its charge level.

Weak battery

In winter, a bad (dead) battery will definitely show itself

In cold weather, a weak battery is not able to create the necessary voltage on the engine plugs, a weak spark does not ignite the fuel. And if in the summer you can start and drive with a weakly charged battery, then in winter such a "number" will not work.

Bad fuel

Also, candles are filled in due to low-quality fuel, so it is recommended to refuel at proven gas stations, especially in winter. The candles themselves must be controlled, and, if necessary, new ones must be purchased.

To prevent candles from flooding in frost, it is recommended to adhere to the following sequence: first turn on the low beam headlights for a few seconds. This will give the battery a light load. Then you need to turn off the headlights and after waiting 1 - 2 minutes, try to turn the starter, and then start the engine. If the attempt is unsuccessful, you can repeat it after 5 - 7 minutes. If, nevertheless, the power of the battery is not enough, then it should be removed and taken to a warm place overnight.

There is always a way out!

Flooded candles, as follows from the above, are one of the most common problems for car owners, especially for beginners who did not have to operate a car in winter.

But even inexperienced drivers will find a way out of any situation: the battery can be recharged, and the candles can be “blown out”, cleaned and dried, or bought new ones. Moreover, the cost of candles is small.

Occasionally, a removed spark plug may be wet. This can be caused by gasoline, oil or coolant (antifreeze). Each of these liquids has its own determination methods.

Gasoline can be easily identified by its high volatility. By unscrewing the candle, gasoline dries quickly. Most often, filling with gasoline occurs when starting a cold engine. It can also happen due to incorrect ignition adjustment.

Oil on the spark plug electrodes can appear due to significant wear on the valve stem seals. Less often, the cause may be wear of the cylinder-piston group of the engine or breakage of oil scraper rings on the piston. Any of these faults require immediate repair.

The amount of oil on the spark plugs can indicate how serious the problem is. When diagnosing, it is best to use a set of new spark plugs recommended by the car manufacturer, as oil droplets are clearly visible on a clean insulator. The first stage is the appearance of small dark specks from the burnt oil. This will not affect the performance of the spark plug in any way, but it will indicate that there are still problems with the engine. The manifestation of the next stage of oil entering the combustion chamber will be wetting the lower thread of the spark plug. This condition of the plug will cause pops in the muffler at idle speed. They disappear with increasing engine speed.

The last stage is the complete wetting of the candle from below. In this situation, the spark does not form at all. Consequently, a cylinder with such a plug does not work. You can find out about this by regularly banging the muffler, which does not stop with increasing speed. The engine starts to triple.

If oil enters the combustion chamber with 100% serviceable fuel supply and ignition systems, then its combustion occurs at the spark plug electrodes. As a result, the oil does not have time to wet the candle. This is not to say that this is good, but it is not too bad either. In this case, droplets of combustible oil turn into ash. It accumulates on the electrodes, increasing their thickness. When the engine is running, the ash heats up well. This contributes to the further combustion of the incoming oil. It is easy to clean, but it is best to do this at the same time as replacing the valve seals. If you remove the ash from the candle, the oil may stop burning. Because of this, the spark may stop skipping, the candle will flood, and the cylinder will stop working.

Sometimes "craftsmen" use the following methods of dealing with candle flooding: install candles with a shorter skirt or with a higher glow number, increase the spark voltage by putting on high-voltage tips, leaving a small gap. All these methods are short-lived, ineffective, and are dangerous for the condition of the car.

The reasons for the ingress of coolant may be the following: poorly pressed cylinder head, a crack in it or in the liner body, a leaky carburetor heating system. As for the latter reason, it is typical only for Japanese cars.

In practice, it is difficult to determine whether antifreeze enters the combustion chamber, since when the engine warms up, some holes may close as a result of metal expansion. Diagnostics must be carried out on a cold engine. This requires starting the car for about 10 seconds. During this time, the candles will not have time to heat up and the cracks will not disappear. On a twisted plug, the coolant looks like dew droplets.

When buying new spark plugs, you should be wary of fakes, as they can damage the entire engine. They can be identified by a curved or uneven inscription, poor-quality processing of the candle hexagon, poorly executed packaging.