Checks when starting the engine

Engine started and running properly

1. Before starting the engine, it is necessary to install the gear selector lever (AKP) into position «R», or in position «N» if the gearbox is manual.

2. It is necessary to check the performance of the vacuum booster of the brake system. To do this, press the brake pedal and start the engine, while the brake pedal should move slightly due to the application of foot force, in this case the vacuum booster is functioning normally. If during start-up, the brake pedal did not move, it is recommended to contact the service station for a more detailed diagnosis of the car.

3. Modern cars are equipped with electronic control units (ECU), so there is no need to keep the accelerator pedal depressed when starting. The electronics will independently increase the engine speed for faster warm-up, then lower it to normal idle speed.

4. When starting, some signaling devices of individual vehicle systems light up, at this moment self-diagnosis of these systems is performed, after a few seconds the signaling devices should go out. If any of the indicators does not go out, you must refer to the section in this manual «Vehicle operation» or at the service station.

5. In winter, for cars with a manual transmission, in order to simplify the engine start, it is necessary to depress the clutch pedal before starting. If a diesel engine is installed, then the car may be equipped with a preheating system, which turns on automatically before starting, and a special indicator lights up, after turning off which you can start the engine.


6. It is advisable, after a successful start of the engine, open the hood cover and look at all the main elements of the engine to make sure there are no leaks (in the main interface points: the head of the block to the block of cylinders, the oil pan to the block of cylinders, the gearbox to the engine). Also check the coolant and brake fluid levels in the expansion tanks. If necessary, top up to the required level.

7. Check the functioning of all elements of the lighting system. If any problems are found, see chapter «electrical equipment» or contact the service station. You should check:

• A) headlights (dipped/high beam headlights/fog lights).
• b) Direction indicators and indicator repeaters (front and rear).
• With) Rear brake lights, rear fog light and car reversing light.

Engine does not start, crankshaft does not turn

1. Check the battery charge level.

2. Check and make sure that the wiring terminals are connected to the battery properly (see chapter «Vehicle operation»). Also check the wiring terminals for oxidation (clean terminals if necessary).

3. Make sure that the high voltage wires of the spark plugs are connected correctly. Also check the wire/wires of the ignition coil/coils.

4. Check the fuses of the starting system (see below «Actions in an emergency»).

5. Check the correct wiring connection to the starting system starter.

6. Check the technical condition of the spark plugs (see below figure).

7. Check ignition system fuses (see below «Actions in an emergency»).


8. Using a hydrometer, measure the density of the electrolyte in each battery cell (see chapter «Engine electrical equipment»).

9. Using a voltmeter, measure the voltage at the battery terminals.

10. Check the technical condition of the starter (see chapter «Engine electrical equipment»).

Engine does not start, crankshaft turns

1. Check the fuel level in the fuel tank. At the same time, be careful and careful, since some models are equipped with electric fuel pumps, which are lubricated by the fuel itself, therefore. at full fuel consumption, the pump will work «dry», which may cause it to break. It should also be taken into account that the low fuel indicator lamp lights up if there is 5-8 liters of fuel left in the tank.

2. Check and make sure that the wiring terminals are connected to the battery properly (see chapter «Vehicle operation»). Also check the wiring terminals for oxidation (clean terminals if necessary). If the terminals are oxidized, the crankshaft may turn very slowly and stop.

3. Alternatively, it is possible that the engine «picks up» (starts, cranks a few turns, then dies), but won't start. The reason may be air leakage in any of the elements of the intake system (see chapter «Intake and exhaust system»). Air leakage is possible from the following points of junction of the elements of the intake system:

• a) Place of attachment of the throttle body to the air duct (towards the intake manifold).
• b) The location of the air duct to the intake manifold.
• c) Mating the intake manifold to the cylinder head.
• d) Also, on some vehicles, suction is possible through a loose mount of the intake air temperature sensor.

4. Check the sensors of the engine management system. Modern engine control systems use many sensors that read information about certain parameters of a mechanism or system and send signals to the electronic control unit (ECU/ECM/PCM), all this is done to optimize and improve the working processes of the engine. But, there are sensors that, if they fail, will indirectly affect the operation, while the engine will continue to work (change in fuel consumption and / or decrease in power, any interruptions in operation are possible), and the warning light on the instrument panel will light up «CHECK ENGINE». There are also several main sensors, if they fail, the engine will not start, namely:

• a) Excess oxygen sensor (Lambda probe). On modern cars, it is installed before and after the catalytic converter (see chapter «Engine management system»).
• b) crankshaft position sensor (see chapter «Mechanical part of the engine»). It is mounted either above the flywheel at the rear of the engine, or at the front of the engine.
• c) Mass air flow sensor. Installed in the air duct of the intake system, in front of the throttle valve (see chapter «Engine management system»).

5. In winter (at the first start in the morning after a night in the garage or in the parking lot) very slow cranking is possible, insufficient to start the engine. The reason may be (provided that all other systems and elements are in good working order) battery freezing. To warm up the battery, it is necessary to turn on the high beam headlights for 1-2 minutes. Then try again to start the engine, if the engine does not start, see possible causes above. If the car is equipped with a diesel engine, the formation of paraffin plugs in the fuel lines and fuel channels may be a possible cause (this violation is typical for cars that are idle for a long time in an unheated parking lot).

6. If the car has stood overnight in an open parking lot in winter, then a difficult start is possible due to thickening of the engine and transmission oil.

Engine starts but runs rough

1. Malfunctions in the fuel system (see chapter «Supply system»). The cause of malfunctions may be a malfunction of the fuel pump (injection pump, for diesel engines), airiness of the fuel lines, contamination of the nozzles of the fuel injectors, heavy carbon deposits on the nozzles of the injectors (diesel engines). All work related to the elements of the fuel system is recommended to be carried out at specialized service stations.


2. The reason may be air leakage in any of the elements of the intake system (see chapter «Intake and exhaust system»).

• a) Air leakage is possible from the following points of interface of the elements of the intake system.
• b) Place of attachment of the throttle body to the air duct (towards the intake manifold).
• c) The location of the air duct to the intake manifold. Mating the intake manifold to the cylinder head.

Malfunctions in the ignition system (only petrol). When working with elements of the ignition system, it is recommended to carry out work at specialized service stations. You can check the following yourself:

• A) Correct connection of high voltage wires. The wires should fit snugly on the tips of the candles and on the ignition coils.
• b) The technical condition of the spark plugs and the compliance of the installed spark plugs with the technical requirements of the automaker. Also, by soot or deposits on the electrodes of the spark plug, you can determine what malfunctions have occurred in the engine (see picture).

Note. There are two main types of candles: hot and cold.

• With) Check the quality of the fuel being poured.

3a. Violation in the operation of the injection pump (high pressure fuel pump), associated with the displacement of the start of injection and the time of fuel injection. The reason may be the displacement of the injection pump drive sprockets (provided that the pump was removed and installed) with respect to the drive chain or belt.

4. Violation of the installation of the gas distribution phases. In this case, the operation of the engine can continue, but with increased fuel consumption and a large loss of power. There are many reasons that can lead to such a violation, but the main two are:

• A) Check the quality of the fuel being poured.
• b) When replacing the drive chain / timing belt (gas distribution mechanism) phase shift has occurred. Violations about the operation of the electronic engine control unit (ECU).

5. Violation of the installation of the ignition timing. If the ignition timing has shifted to a later value, then interruptions in the operation of the engine may be accompanied by pops in the vehicle's exhaust system, as well as the presence of black smoke from the exhaust pipe. In this case, it is necessary to stop the engine as soon as possible, since unburned fuel in the cylinders will burn out in the catalytic converter, which can lead to its failure. If, during interruptions in the operation of the engine at idle, pops are heard in the intake manifold, this indicates a shift in the angle to the zone of earlier ignition. Violations of the ignition timing lead to serious consequences that may result from overloading of individual elements, components and engine systems.

6. Violations in the recharging system. At the same time, in the cabin on the instrument panel, after starting the engine, the warning light will light up indicating that the battery is not being charged. In this case, it is necessary to check the connection points of the electrical wiring to the generator. If the wiring is connected properly, you need to contact the service station.

7. If blue smoke comes out of the exhaust pipe when the engine is running, then the cause may be the ingress of engine oil into the cylinders (through valve sleeves or through piston rings, see chapter «Mechanical part of the engine»), due to which carbon deposits form on pistons, candles and nozzles, as a result of which the engine starts to work intermittently. In this case, it is necessary to contact the service station for repair work.

For diesel engines:

If black smoke is coming out of the exhaust pipe and the engine is running rough, the cause may be that the injector nozzle is not tightly closed by the valve, which leads to fuel leaks into the cylinder.

8. Also, a malfunction of the engine may be due to a decrease in compression in one or more engine cylinders (see chapter «Mechanical part of the engine»).