Determining the cause of a malfunction can be determined not only by an experienced professional auto mechanic, but also by a car enthusiast who independently carries out repairs and maintenance of his car. When faced with any problem, the first step is to decide where to start looking for the cause. Sometimes it's obvious, other times it's not. Proceed with the analysis, first of all, eliminating the simplest causes of problems. It happens that a car malfunction is not due to a breakdown of its components. For example, a failure to start the engine may occur due to a lack of fuel in the tank or due to the fact that the car has been sitting all night with the headlights on. An owner who has made half a dozen adjustments or replacements may get lucky and the malfunction (or its symptoms) will disappear, but he will not know what to do if such a problem occurs again and, perhaps, will spend more time and money than necessary. If an electrical fault occurs as a result of loosening one of the contacts, it is also necessary to inspect other connections of the system so as not to encounter such a breakdown again in the near future. Remember that failure of parts such as fuses or spark plugs can only be a consequence of more serious faults. Failures can occur not only as a result of a sudden breakdown, but also due to the accumulation of damage over time. Serious malfunctions are usually preceded by characteristic symptoms that appear hundreds or even thousands of kilometers before the breakdown.
Engine
1 The crankshaft does not rotate when trying to start the engine
1. Battery contacts are loose or oxidized. Inspect the battery terminals. Tighten terminals and/or remove corrosion deposits from terminals as necessary.
2. The battery is discharged or defective. If the terminals are tight and there is no corrosion deposits on the terminals, turn the ignition key to the «ON» and turn on the headlights and/or windshield wipers. If the devices do not work, the battery is low.
3. It is not possible to set the automatic transmission selector lever to the position «PARK» or «NEUTRAL».
4. Irregularities in the electrical wiring of the starter circuit. Inspect the wiring and connections at the battery, starter relay, and ignition switch.
5. The starter gear slips along the flywheel ring gear. At your earliest convenience, remove the starter and inspect the gear and drive disc (chapter 5).
6. Starter traction relay is faulty (chapter 5).
7. Starter malfunction (chapter 5).
8. Malfunction of the ignition switch (chapter 12).
2 The engine crankshaft rotates when starting, but the engine does not start
1. Lack of fuel in the tank, clogged fuel filter or fuel line.
2. Malfunction of the fuel injection system (chapter 4).
3. Battery is low (starter rotates slowly). Inspect the electrical equipment as described in the previous subsection.
4. Battery contacts are loose or oxidized (see previous subsection).
5. Fuel pump malfunction (chapter 4).
6. Broken or disconnected wiring in the starter circuit (see previous subsection).
7. Malfunction of ignition system elements (chapter 5).
3 The starter works, but the crankshaft does not rotate
1. Sticking of the starter gear. Remove and inspect the starter (chapter 5).
2. Worn or broken off starter gear teeth or drive disk ring. Remove the service cover of the drive disk and inspect it.
4 Difficulty starting a cold engine
1. The battery is completely or partially discharged. Carry out inspection and restoration as described in subsection 1.
2. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
5 Difficulty starting a warm engine
1. Air cleaner element clogged (Chapter 1).
2. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
3. Low compression in cylinders (chapter 2).
4. Malfunction of elements of the fuel vapor recovery system (EVAP) (chapter 6).
6 The starter operates jerkily or makes unusual noise when operating
1. Worn or broken teeth of the starter gear or drive disk ring. Remove the cover located at the rear of the engine (if its presence is provided for by the design) and perform an inspection.
2. Loose tightening force or loss of starter mounting bolts.
7 The engine starts but immediately stalls
1. Loosening or failure of electrical wiring connectors in the generator or ignition coil circuit (chapter 5).
2. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
3. Depressurization of the mating surface of the intake manifold or throttle block. Make sure that the fastening bolts/nuts are securely tightened, as well as that the connections are secure, correctly laid, and in good condition of the vacuum hoses connected to the manifold.
4. Limitation of the patency of inlet or outlet channels (chapter 4).
5. Inconsistency of the entered security code, as a result of which the fuel injectors were turned off immediately after starting the engine.
8 Engine stalls or idles erratically
1. Depressurization. Make sure that the intake manifold and throttle body mounting bolts/nuts are securely tightened. Make sure that the connections are secure and that the vacuum hoses are in good condition. With the engine running, make sure the hoses are tight by listening to them with a stethoscope, which can be used as a piece of an old brake hose. When you bring the stethoscope to the depressurization site, you will hear a hissing sound. You can also apply a soap solution to the hoses to check for depressurization.
2. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
3. The passage of the hose or valve of the crankcase ventilation system is limited (chapter 6).
4. The air filter element is clogged (Chapter 1).
5. There is not enough fuel supplied from the pump to the injectors (chapter 4).
6. Depressurization of the cylinder head interface. Perform a cylinder compression test (Chapter 2B).
7. Wear of camshaft cams (chapter 2).
9 Reduced engine idle speed
1. Worn spark plugs or incorrect installation of the interelectrode gap (Chapter 1).
2. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
3. Failure of spark plug wires (Chapter 1).
4. Depressurization from hose connections or intake manifold. Perform the test.
5. Uneven or low compression in the cylinders. Take the measurement as described in Chapter 2B.
10 Reduced engine speed throughout the entire operating range
1. Clogged fuel filter and/or dirty fuel system (Chapter 1).
2. Incorrect installation of the interelectrode gap or failure of the spark plugs (Chapter 1).
3. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
4. Failure of spark plug wires (Chapter 1).
5. Malfunction of exhaust system elements (chapter 6).
6. Uneven or low compression in the cylinders. Remove the spark plugs and use a compression gauge to measure (Chapter 2B).
7. Depressurization of the intake manifold, throttle body or vacuum hoses (see subsection 8).
11 Engine stalls
1. Clogged fuel filter and/or clogged/moisture entering the fuel system (Chapter 1).
2. Failure of sensors or a problem in the fuel system (chapter 4 and 6).
3. Malfunction of exhaust system elements (Chapter 6).
4. Incorrect installation of the interelectrode gap or failure of the spark plugs (Chapter 1). Also inspect the spark plug wires (Chapter 1).
5. Depressurization of the intake manifold, throttle body or vacuum hoses.
12 Engine power decreases
1. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
2. Incorrect adjustment of the interelectrode gap or failure of the spark plugs (Chapter 1).
3. Failure of the ignition coil (chapter 5).
4. Brake jamming (chapter 9).
5. Incorrect level of transmission fluid in the automatic transmission (Chapter 1).
6. Clogged fuel filter and/or fuel system elements (Chapter 1).
7. Malfunction of the emission control system (chapter 6).
8. Use of fuel that does not meet technical requirements. Fill with fuel of the required standard.
9. Reduced or uneven compression in the engine cylinders. Carry out a compression test, which may indicate gas leakage through the valves or failure of the cylinder head gasket (chapter 2).
10. Limitation of intake or exhaust system capacity (chapter 4).
13 Backfires occur
1. Malfunction of the emission control system (chapter 6).
2. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
3. Malfunction of the secondary circuit of the ignition system (Insulator cracking or spark plug wiring failure) (chapter 1 and 5).
4. Malfunction of injection system elements (chapter 4).
5. Depressurization of the throttle block, intake manifold or vacuum hoses. Perform the test.
6. Valve jamming (chapter 2).
14 The engine rattles or detonates when the speed increases or the load increases
1. Refueling with fuel with inappropriate characteristics. Fill the car with fuel with the appropriate octane rating.
2. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
3. Installation of the wrong type or damaged spark plugs/wires. Check the correct type of spark plugs installed using the vehicle identification number plate (VECI), located in the engine compartment. Also inspect the spark plugs and their wires (Chapter 1).
4. Malfunction of the emission control system (chapter 6).
5. Depressurization of elements. Perform the test.
15 The engine continues to run after the ignition is turned off
1. Malfunction of elements of the fuel system or ignition system (chapter 4 or 5).
2. Increased engine operating temperature. This may have happened due to a decrease in coolant level (Chapter 1), failure of the thermostat, clogged radiator or breakdown of the cooling system pump (chapter 3).