VAZ won't start? Causes, elimination

Dima Kashevsky [kashevsky_dima]

04.10.2020,

I often encountered a problem when a VAZ would not start. Owners of injection and carburetor cars contacted us. Below I will list common causes that should help with your problem. Before that, it’s only worth saying that below we will talk about both old and new models. The material is voluminous, because I decided to describe everything in detail.

There are three main reasons why a domestic car does not want to start:

• Lack of fuel in the combustion chamber
• Lack of oxygen
• No ignition

As a rule, 80 percent of malfunctions lie in these three reasons. Let's take a closer look.

Ignition problems

The most common malfunction. The spark itself may exist, but its strength is not sufficient to ignite the fuel mixture. To identify the problem, the first step is to check the spark plugs.

In case anyone doesn't know, spark plugs can be found by the wide wires coming from them. We need to determine which candle has failed, because they cannot all break at once. To check, you need to start the VAZ engine and listen to the sound of its operation. Next, we unscrew the spark plugs one by one and listen to how the sound of the engine changes. When you remove a faulty spark plug, the sound of the engine will not change.

Inspect the unscrewed spark plug. By the carbon deposits on it you can determine why it failed. Most likely, the electrode will have one of the following deposits:

• Of red color. Occurs due to the addition of various additives to car fuel. If you see this type of carbon deposits, then you should refuse additives, because soon you will have to change the remaining spark plugs.
• White (similar to plaque). Indicates that the fuel mixture is unbalanced. This means that it is formed in the wrong oxygen/fuel ratio. There may be either an excess of fuel or an excess of oxygen.
• Matt black color. Occurs due to an excess of gasoline in the fuel mixture. Reason: the carburetor is incorrectly adjusted or the injector is not working correctly. Another symptom: increased fuel consumption.
• Oil black. Logically, this indicates increased oil consumption, which gets onto the electrode and interferes with the formation of a spark.

No fuel supply

When problems arise with the fuel supply on a VAZ 2107, regardless of the engine type, it simply will not be possible to start the power unit. You will need to understand the reasons and fix the problem.

On the injector

On an injection engine, the fuel pump located in the tank may break down. We check its performance and, based on the results obtained, perform certain actions: repair or carry out further diagnostics. Checking the fuel pump on the injection “seven” is quite simple: just turn on the ignition and listen to the operation of the mechanism. If there are no signs of the node functioning, it is worth understanding the lack of performance in more detail.

On the carburetor

With a fuel pump on a carburetor engine, things are somewhat more complicated: the mechanism will have to be dismantled, disassembled and the condition of its structural elements diagnosed. Malfunction of the pump leads to the fact that fuel does not flow into the carburetor float chamber or does not flow in sufficient quantities. You can try to pump up gasoline manually, and also check the fuel pump:

If the fuel volume is less than 1 liter, the fuel pump is considered faulty.

Faulty starter

The problem with the starter on VAZs is very relevant. According to statistics, before a major overhaul of the engine, there is a need to repair the starter at least once. After checking the spark plugs, I advise you to pay attention to this mechanism and most likely the fault will lie there.

To determine the problem, you need to determine what type it is:

• Electric
• Mechanical

It is very easy to determine: if the starter does not turn and the VAZ does not start, then the problem is in the electrics. If you hear it spinning, then there is a mechanical problem. Let's figure out what can break down in the starter's electrics and what can go wrong in the mechanics.

Checking the contact.

Start checking with the simplest thing: inspecting the terminals on the mechanism body. Due to our “great” weather conditions, they like to oxidize, causing contact to be lost. As a result, the control impulse does not reach the motor and when we turn the ignition key we hear nothing. To clean the terminals, a regular fine knife or natfel will do.

Advice: to avoid corrosion of the terminals, you should treat them with lithol. It is first necessary to clean off any pockets of corrosion.

During the test, you will be able to confirm that there is no open circuit: each wire should be fixed to the starter terminals. Without diagrams on all VAZ models, the connection is similar:

• One “plus” from the battery goes to the starter terminal
• The second “plus” comes from the ignition switch through the fuse box

Check the fuse box, as a blown fuse breaks the circuit and no control voltage is supplied to the starter. Just visually check the fuse and if you see that it has burned out, replace it.

Checking the serviceability of the retractor

relay. This device is responsible for extending the bendix. Diagnosing a malfunction of the solenoid relay is easy, since it operates with a characteristic clicking sound.

A clicking sound appears when you turn the ignition key. If the solenoid relay does not click, then the problem lies with it or its fuse. Unfortunately, this part cannot be repaired, but it is inexpensive. By the way, there is a simple trick that often helps to revive a broken solenoid relay: you just tap it lightly with a hammer several times. In most cases this method works.

Broken Bendix gear teeth.

This is a rather rare type of reason why a VAZ will not start, but it is very easy to diagnose: an unpleasant metallic grinding sound will be heard from under the hood after turning the ignition key.

The problem is resolved by replacing the starter.

Another common reason why the starter does not turn and the VAZ does not start: a blown starter fuse. In this case, the solenoid relay does not click.

Car with fuel injection system

The process of checking the operation of an injection engine is both simpler and more complex. The causes of malfunction are significantly fewer than with a carburetor. At the same time, eliminating them is much more difficult. There are actually only two reasons: lack of gasoline and spark. The presence of a special light bulb - Check Engine - simplifies the work somewhat.

If any malfunction occurs, it lights up immediately. Typically, if the engine cannot be started, the error code will be PO3ХХХ. Indicates misfires in the cylinder. But first you need to make sure there is a spark in the engine. If you have problems starting the engine on a VAZ 2106 with a carburetor, you should:

• use a diagnostic scanner - when an error is detected, it is very easy to identify the part that allows you to identify the malfunction by its number;
• replacing the ignition module - often the problem lies in this unit; it fails quite often.

A typical problem with all VAZ engines is the failure of a pair of transistors. Each of them is responsible for the normal operation of 2 cylinders. Moreover, they burn out at the same time. The main sign of such a malfunction is that there is no spark at all. But often there is a spark - but the engine still does not start. In this case, you need to check the spark plugs:

• if there is no fuel or oil on the spark plugs, you should check the presence of power to the injectors (by removing the connector of one of them, you need to check the presence of voltage with a conventional tester set to 12 V DC);
• measure the pressure in the fuel pump.

Sometimes the problem lies in the fuse that supplies power to the fuel pump. It is also advisable to replace the fuel pump with a known good one. If the car does not start only when it is hot, then the problem may lie in the engine itself. It is advisable to seek advice from a car service center or specialists.

It will not be difficult to independently check the serviceability of the engine and its other systems - you just need to use a tester. Carburetor systems are much easier to repair, but problems are often difficult to find. The injector usually requires the assistance of a specialist.

Fuel pump malfunction

With this malfunction, the Zhiguli engine starts, and then stalls or does not start at all. The first step is to check whether the fuel pump fuse is working properly, because according to statistics, 60 percent of VAZ fuel pump failures are associated with a blown fuse. In VAZ 2105 it is located in a block under the hood near the windshield, in VAZ 2107, 2109, 2115 in the cabin below the dashboard. In VAZ 2110, 2111 and 2112 it is located in the cabin in the place of the front passenger's feet. Next to the fuses there are relays, which are also responsible for the operation of the fuel pump. If the fault is not in the fuse or relay, then it lies either in the fuel pump itself or in its power supply circuit.

In carburetor VAZs, the fuel pump is located in the engine compartment next to the cylinder head.

All “classics” such as the Zhiguli were equipped with a fuel pump called DAAZ. Its catalog number is: 1106010. The part is very reliable, so the likelihood that the problem is with it is not high. And even if it breaks, you can buy repair kits.

In injection VAZs with a fuel pump, everything is not so fabulous.

It is hidden in the gas tank and likes to fail if there is little fuel inside. The pump motor is electric and is cooled by the gasoline itself, in which it is located. If there is little gasoline, the pump does not cool well, overheats and eventually breaks down.

The car may have difficulty starting due to low fuel content in the tank.

Other problems

Both on the carburetor and on the injector, the main reason that prevents the engine from starting is problems with the starter. If it does not rotate, then you will have to figure out why. Possible breakdowns:

• winding break;
• solenoid relay failure;
• poor contact in the wiring;
• discharged battery.

Also, the car may not start due to lack of gasoline.

The ignition coil and lock will have to be checked if nothing else helps. When it turns out that the problem is in the first one, it is removed and replaced with a new one. In the second case, first of all, look to see if the wire has broken somewhere.

In the ignition system, the distributor is also a vulnerable element. Remove the cover from it - if it is damaged, replace it. You need to do the same with the slider and hall sensor.

In winter, condensation sometimes freezes in the fuel rail. Warming up with a hairdryer or blowing with a compressor helps.

Crankshaft position sensor

The sensor itself is very reliable, and there is nothing to break there. However, it can become clogged with a thick layer of dirt and stop functioning. The way out of the situation is simple: just wipe it. As a rule, it cannot become dirty immediately and the problem will manifest itself gradually: at first your VAZ does not start well, and after a month the car is no longer able to start.

Since a lot of dirt accumulates on this sensor, its contact with the wire simply rots. This is already a common problem, but it can be easily solved by manually restoring contact. The crankshaft sensor is located on the oil pump.

It is important to know! It is not permissible to make contact using twists. So you will lose it in a month, so it is best to solder the contact and cover it with lithol.

VAZ starts and immediately stalls

The car may stall immediately after starting, even due to trivial little things such as consumables. Therefore, first of all, I advise you to check the fuel and air filters. If they are clogged, it is difficult for the engine to receive oxygen and fuel, which causes it to simply stall.

If before your VAZ stopped starting, the following were discovered:

• Power Loss
• The car doesn't start well
• Increased fuel consumption

It is most likely that the catalyst that is equipped with VAZ injection models is faulty. The catalyst can be removed by flashing the engine control unit. As an alternative: install lambda decoys. A clogged catalyst may also be the reason why the VAZ does not start.

Fuel system

The quality of functioning of the vehicle’s fuel system components and the proper operation of the engine starting system are interconnected.

Main elements of the system: Fuel pump (9), Fuel filter (2), The line itself (3), Fuel rail (5), Injectors (7), Fuel pressure regulator (RDT) (4), Return line (8), Spool valve for measuring pressure (6)

Serviceability characteristics, violations of which lead to a failure in the starting system:

1. amount of gasoline; if there is little of it, then drawing in gasoline by the pump will become impossible,
2. breakdowns, leaks in the fuel supply,
3. Fine filters become clogged, resulting in a decrease in pressure.