Why the VAZ 2107 engine does not start

Often, owners of domestic classics, say, VAZ 2106 or VAZ2107, are faced with the problem of starting the engine. Such a situation can occur in any period of the year and in any weather.

In some cases, changes in weather conditions are the main cause of difficulty starting the engine. For example, in the winter, after a long period of inactivity, the engine will not start as quickly as in the summer.

Consider the most common causes and possible options for their elimination. A this review tellshow to repair a VAZ 21099 for a beginner if there are no suitable tools at hand.

Possible causes of failure

If you classify all the malfunctions due to which the engine does not want to start, you will get only two categories:

• malfunctions in the fuel system;
• malfunctions of the ignition system.

In most cases, a professional can immediately identify a problem. Each malfunction is accompanied by a certain “behavior” of the motor. For most motorists, the engine simply does not start.

Here are some signs by which you can determine the malfunction, so as not to try to “repair” a working part or assembly without a reason.

No spark or weak spark

If the VAZ 2107 engine does not start, the first thing you need to pay attention to is whether there is a spark, and if so, is it powerful enough to ignite the air-fuel mixture. To determine this, you should check:

• spark plug;
• high voltage wires;
• distributor;
• ignition coil;
• voltage switch (for contactless ignition) and a Hall sensor;
• crankshaft position sensor.

Spark plug

They are checked as follows:

• you need to unscrew one candle, put a candlestick on it;
• lean the side electrode against the cylinder head;
• the assistant starts to scroll the starter;
• high-quality spark should be thick and blue. In the case of a red spark or its absence, the candle should be replaced with a new one. If replacing a separate candle did not solve the problem of the lack of spark, then you need to look for the cause in other elements of the system.

So all four candles are checked. If there is no spark on one or several cylinders and replacing the candles did not solve the problem, it is necessary to check the next element - high-voltage wires.

High voltage wires

Before you go to the store for new wires, it is important to make sure that the problem is really in them. To do this, the candle, on which there was a spark, is twisted, a wire of the idle cylinder is put on it. If a spark did not appear when cranking the starter, then a worker from an adjacent cylinder is installed in place of this wire.

The appearance of a spark indicates a malfunction of a separate explosive cable. It is solved by replacing a set of cables. If the discharge still does not appear, then the center wire is checked. The procedure is identical - the candlestick is put on the working candle, which is leaned against the "mass" with the side electrode (the distance between the contact and the head body should be approximately a millimeter). Cranking the starter should produce a spark. If it is, the problem is in the distributor, if not, in the ignition coil.

There are frequent cases when in wet weather (heavy fog) the car does not start even when the ignition system is perfectly tuned. Pay attention to the BB wire. Sometimes the problem arises from the fact that they are wet. You can ride the car around the yard all day (to start the engine), but until the wet wires are wiped dry, nothing will work.

When working with high-voltage wires, it is important to remember: the voltage in them is very high, so you need to hold them not with your bare hands, but with pliers with good insulation.

Timer

If checking the candles and high-voltage wires did not give the desired result (but there is a spark on the central wire), then the problem can be found in the contacts of the ignition distributor cover.

They remove it and check for cracks or deposits in it on the contacts. If they are slightly burnt, they must be carefully cleaned (you can use a knife).

Additionally, the contact "K" is checked. If there is no voltage on it, the problem may be in the ignition switch, power cord or fuse. Also checked the clearances on the contacts of the chopper (probe 0,4 mm.) And the health of the resistor in the slider.

Ignition coil

The easiest way to check for a possible coil malfunction is to set up a working one. If a multimeter is available, then the diagnosis should show the following results:

• For the B-117 coil, the resistance of the primary winding should be from 3 to 3,5 ohms. The resistance in the secondary winding is from 7,4 to 9,2 kOhm.
• For a coil type 27.3705 on the primary winding, the indicator should be in the range of 0,45-0,5 Ohms. The secondary should show 5 kOhm. In case of deviations from these indicators, the part must be replaced.

Voltage Switch and Hall Sensor

The switch is easiest to verify by replacing it with a working one. If this is not possible, then you can perform the following procedure.

The wire from the switch to the coil is disconnected from the coil. A 12-volt light bulb is connected to it. Another wire connects another wire to connect the “control” to the coil. When scrolling with a starter, it should blink. If there are no "signs of life", then you need to replace the switch.

Sometimes a VAZ 2107 Hall sensor fails. Ideally, it would be nice to have a spare sensor. If it is not, then you need a multimeter. At the output contacts of the sensor, the device should show a voltage of 0,4-11 V. In the event of an incorrect indicator, it must be replaced.

Crankshaft position sensor

This part plays a major role in the sparking process in the ignition system. The sensor determines the position crankshaftwhen the piston of the first cylinder is at top dead center on the compression stroke. At this moment, a pulse is generated in it, which goes to the ignition coil.

With a faulty sensor, this signal does not form, and, as a result, a spark does not occur. You can check the sensor by replacing it with a working one. It is worth noting that such a problem is less common, and in most cases, in the absence of a spark, it does not come to its replacement.

Experienced motorists can determine a specific breakdown by the way the car behaves. Different problems when starting the motor have their own characteristic signs. Here are common problems and their manifestation when starting the engine.

Starter turns - no flashes

This behavior of the motor may indicate a break in the timing belt. Often this problem entails the replacement of valves, since not all ICE modifications have pistons with recesses that prevent deformation of the open valve when it reaches top dead center.

For this reason, the timing belt replacement regulations must be observed. If it is in order, then the ignition and fuel supply system are diagnosed.

1. Fuel system. After cranking the starter, the candle is twisted. If its contact is dry, then fuel does not enter the working chamber. First of all, it is necessary to check the fuel pump. In injection engines, the malfunction of this part is determined by the absence of a characteristic sound after ignition is turned on. The carburetor model is equipped with another modification of the gasoline pump (its device and repair options can be found in separate article).
2. Ignition system If the twisted candle is wet, it means that the fuel enters, but does not ignite. In this case, it is necessary to carry out the diagnostic procedures described above to identify a malfunction of a specific part of the system.

The starter turns, seizes, but does not start

On the VAZ 2107 injection engine, this behavior is typical when the Hall sensor is malfunctioning or the DPKV is unstable. They can be checked by installing a working sensor.

If the engine is carbureted, then this happens with filled candles. Often this is not a car problem, but the result of improper motor starting. The driver pulls the choke cable, presses the accelerator pedal several times. Too much fuel does not have time to ignite, and fills the electrodes. If this happened, you need to unscrew the candles, dry them and repeat the procedure, after removing the suction.

In addition to these factors, the reason for this behavior of the motor may lie in the candles themselves or high-voltage wires.

Starts and immediately stalls

This problem may be due to malfunctions in the fuel system. Possible causes include:

• lack of gasoline;
• poor fuel quality;
• failure of explosive wires or spark plugs.

If the above factors are eliminated, then it is worth paying attention to the fuel filter of fine cleaning. Due to the poor quality of gasoline and the presence of a large number of foreign particles in the gas tank, this element can become contaminated much faster than the time comes to change it according to the maintenance schedule. A clogged fuel filter cannot filter gasoline at the speed with which the fuel pump pumps, so a small amount of fuel enters the working chamber, and the engine cannot operate stably.

When errors appear in the electronic control unit of the injection "seven", this can also affect the start of the engine. This problem is best diagnosed at the service station.

The carburetor power unit may stall due to clogging of the mesh filter element, which is installed at the entrance to the carburetor. It is enough to remove and clean it with a toothbrush and acetone (or gasoline).

Doesn't start cold

If the car is idle for a long time, gasoline from the fuel line returns to the tank, and the one in the carburetor float chamber evaporates. To start the car, it is necessary to pull out the choke (this cable regulates the position of the damper, which blocks the air supply and increases the amount of gasoline entering the carburetor).

In order not to waste battery power to pump fuel from the gas tank, you can use the manual pumping lever located on the back of the gas pump. This will help in the event that the battery is almost discharged, and you cannot turn the starter for a long time.

In addition to the features of the fuel system of the carburetor "seven", the problem of cold start may be in violation of the formation of a spark (either it is weak or does not arrive at all). Then you should check the ignition system using the methods described above.

Doesn't start hot

A malfunction of this type can occur both on carburetor and injector VAZ 2107. In the first case, the problem can be as follows. While the engine is running, the carburetor cools very much due to the fact that it constantly receives cool air. Once hot motor dies, the carburetor stops cooling.

In a matter of minutes, its temperature becomes the same as that of the power unit. Gasoline in the float chamber evaporates quickly. Since all voids are filled with gasoline vapors, restarting (5-30 minutes after the ignition is turned off) the engine after a long trip will result in a mixture of gasoline and its vapor entering the cylinders. Since there is no air, ignition does not occur. In such a situation, candles are simply filled.

The problem is solved in the following way. Turning the starter, the driver fully depresses the gas pedal so that the vapor quickly leaves the carburetor, and it is filled with a fresh portion of air. Do not press the accelerator several times - this is a guarantee that the candles will flood.

On the carburetor classic in the summer, sometimes the gasoline pump does not withstand intense heating and fails.

Injector "seven" may have difficulty starting a hot motor due to a breakdown:

• crankshaft sensor;
• coolant temperature sensor;
• air flow sensor;
• idle control;
• gas pressure regulator;
• fuel injector (or injectors);
• fuel pump;
• at malfunctions of the ignition module.

In this case, the problem is much more difficult to find, so when it occurs, computer diagnostics will be required, which will show which particular node is failing.

Doesn't start, shoots at the carburetor

There are many reasons for this. It is impossible to say unequivocally what kind of malfunction leads to this. Here are some of them:

• Incorrectly connected high voltage wires. This rarely happens, because in most cases each of them has its own length. If the owner of the car accidentally mixed up the order of their connection, this leads to the formation of a spark not at the moment when the piston is at top dead center on the compression stroke. As a result, the cylinders try to work in a mode that does not correspond to the settings of the gas distribution mechanism.
• Such pops may indicate early ignition. This is the process of igniting the air-fuel mixture before the piston reaches top dead center, completing the compression stroke.
• A change in the ignition timing (sooner or later) indicates some malfunctions of the distributor. This mechanism distributes the moment the spark is supplied to the cylinder in a compression stroke. In some cases, it is necessary to check its fastening. Early ignition is eliminated by turning the dial in accordance with the marks on the scale.

• Sometimes such failures indicate a failure of the ignition system switch. In this case, it should be replaced with a new one.
• During car repair, the timing belt (or chain) has shifted, due to which camshaft incorrectly distributes the phases. Depending on its displacement, the motor will either be unstable or will not start at all. Sometimes such an oversight can result in costly replacement bent valves.

• A lean air-fuel mixture can also lead to lumbago in the carburetor. The cause of this problem may be clogged carburetor jets. It is also worth checking out the booster pump. Improper position of the float in the float chamber can cause insufficient gasoline. In this case, you can check whether the float is correctly adjusted.
• Valve burnt or bent. This problem can be identified by measuring compression. If the inlet valve does not completely cover the hole (burned out or bent), then the excess pressure in the working chamber will partially go into the intake manifold.

Doesn't start, shoots in the muffler

Pops in the exhaust manifold often appear as a result of late ignition. The air-fuel mixture in this case ignites after the piston completes the compression stroke and begins the stroke. At the time of the exhaust stroke, the mixture did not burn out yet, which is why shots are heard in the exhaust system.

In addition to setting the ignition timing, you should check:

• Thermal valve clearance. They must close tightly so that during compression of the fuel-air mixture it remains in the combustion chamber of the cylinder and does not fall into the exhaust manifold.
• Is the timing mechanism correctly set? Otherwise, the camshaft will open and close the inlet / outlet valves not in accordance with the strokes that are performed in the cylinders.

Incorrectly set ignition and not adjusted valve clearance over time will lead to overheating of the engine, as well as burnout of the manifold and valves.

The injector seven may suffer from similar problems. In addition to failures, poor contact or failure of one of the sensors, on which the stable operation of the motor depends, can result. In this case, diagnostics will be required, since there are many locations for troubleshooting.

The starter does not work or rotates sluggishly

Such a problem is a frequent companion of inattentive motorists. Left overnight light will completely drain the battery. In this case, the problem will be immediately noticeable - the equipment will also not work. When you turn the key in the ignition, the starter will make clicks or slowly try to crank. This is a sign of a dead battery.

The problem of a discharged battery is solved by recharging it. If you need to go and there is no time for this procedure, then you can start a car with a “pusher”. A couple more tips on how to get a VAZ 2107, if the battery is dead, are described in a separate article.

If the driver is careful and does not leave the equipment turned on at night, then a sharp disappearance of energy may indicate that the battery contact has oxidized or has fallen off.

No fuel

In addition to problems in the ignition system, the VAZ 2107 engine may have difficulty starting if there is a fuel system malfunction. Since they differ from the injection and carburetor ICEs, the problem is solved differently.

On the injector

If the engine equipped with the injection fuel system does not start due to the lack of gasoline supply (it is in sufficient quantity in the tank), then the problem is with the fuel pump.

When the driver turns on the ignition of the car, he should hear the sound of the pump. At this point, the pressure necessary for the operation of the fuel injectors is created in the line. If this sound is not heard, then the engine will not start or will constantly stall.

On carb

If little gas is supplied to the carburetor or it is not supplied at all, then checking the gas pump in this case is a little more difficult. The procedure is performed in the following sequence.

• The fuel hose is disconnected from the carburetor and lowered into a separate clean container.
• For 15 seconds, scroll the starter. During this time, at least 250 ml should be pumped into the tank. fuel.
• At this point, gasoline should pour out under slight pressure. If the stream is weak or none at all, you can buy a gas pump repair kit and replace the gaskets and membrane. Otherwise, the item is changed.

As you can see, there are plenty of reasons for the trouble starting the engine on the VAZ 2107. Most of them can be diagnosed independently without the waste of troubleshooting in a service station. It is important to understand the principle of operation of the ignition and fuel supply system. They work in a logical sequence and to eliminate many malfunctions, no special knowledge in electrics or mechanics is needed.

Questions and answers:

Why can't a VAZ 2107 carburetor start? The main reasons for difficult starting relate to the fuel system (the membrane in the fuel pump is worn out, depletion on the rod, etc.), ignition (carbon deposits on the distributor contacts) and the power system (old explosive wires).

What is the reason if the car does not start VAZ 2107? In case of short-term seizure, check the operation of the gasoline pump (the cylinder is refilled with gasoline). Check the condition of the ignition system elements (spark plugs and explosive wires).

Why doesn't the VAZ 2106 start? The reasons for the difficult start of the VAZ 2106 are identical to the related model 2107. They consist in a malfunction of the ignition system, the fuel system and the power supply of the car.