Determining the cause of a malfunction is possible not only for an experienced professional auto mechanic, but also for a car enthusiast who independently performs repairs and maintenance of his car. Whenever a problem occurs, the first step is to decide where to start looking for the cause of the problem. Sometimes it's obvious, other times it's not. Start your analysis by eliminating the most basic causes of the problem first. It happens that a malfunction in the operation of a car does not occur due to a breakdown of its elements. For example, failure to start the engine may occur due to lack of fuel in the tank or because the car has been parked all night with the headlights on. An owner who has made half a dozen adjustments or replacements may get lucky and the fault (or its symptoms) will disappear, but he will not know what to do if such a problem occurs again and may end up spending more time and money than necessary. If an electrical fault is caused by one of the contacts becoming loose, it is also necessary to inspect other connections in the system to avoid encountering such a fault again in the near future. Remember that failure of components such as fuses or spark plugs may only be a consequence of more serious faults. Malfunctions 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 signs 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. The battery contacts are loose or oxidized. Inspect the battery terminals. Tighten the terminals and/or remove any corrosion from the terminals if necessary.
2. The battery is discharged or faulty. If the terminals are tight and there is no corrosion on the terminals, turn the ignition switch to the "ON" position and turn on the headlights and/or windshield wipers. If the devices do not work, it means the battery is discharged.
3. It is not possible to set the automatic transmission selector lever to the "PARK" or "NEUTRAL" position.
4. Faults in the starter circuit wiring. Inspect the wiring and connections at the battery, starter solenoid, and ignition switch.
5. The starter gear slips along the flywheel ring gear. At the first opportunity, remove the starter and inspect the pinion and drive disc (Chapter 5).
6. The starter traction relay is faulty (chapter 5).
7. Starter malfunction (chapter 5).
8. Ignition switch malfunction (chapter 12).
2 The engine crankshaft rotates when starting, but the engine does not start
1. No fuel in the tank, clogged fuel filter or fuel line.
2. Malfunction of the fuel injection system (chapter 4).
3. The battery is discharged (the starter turns slowly). Inspect the electrical equipment as described in the previous subsection.
4. The battery contacts are loose or oxidized (see previous subsection).
5. Fuel pump malfunction (chapter 4).
6. Break or disconnection of 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. Starter gear jamming. Remove and inspect the starter (chapter 5).
2. Wear or breakage of the starter gear teeth or the drive disk ring gear. Remove the drive disc service cover and inspect.
4 Difficulty starting a cold engine
1. The battery is completely or partially discharged. Perform inspection and restoration as described in subsection 1.
2. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
5 Difficulty starting a warm engine
1. The air cleaner element is clogged (chapter 1).
2. Malfunction of fuel system or ignition system components (chapter 4 or 5).
3. Low compression in cylinders (chapter 2).
4. Malfunction of the fuel vapor recovery system (EVAP) components (chapter 6).
6 The starter operates with jerks or makes an unusual noise when operating
1. Wear or breakage of the starter gear teeth or the drive disk ring gear. Remove the cover located at the rear of the engine (if its presence is provided for by the design) and carry out an inspection.
2. Weakening of tightening force or loss of starter mounting bolts.
7 The engine starts but immediately stalls
1. Loose or damaged electrical wiring connectors in the generator or ignition coil circuit (chapter 5).
2. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
3. Depressurization of the mating surface of the intake manifold or throttle body. Make sure that the mounting bolts/nuts are securely tightened, and that the connections, installation, and condition of the vacuum hoses connected to the manifold are secure, correct, and in good condition.
4. Restriction of the flow of inlet or outlet channels (chapter 4).
5. The entered security code did not match, resulting in the fuel injectors being switched off immediately after the engine was started.
8 The engine stalls or idles unsteadily
1. Depressurization. Make sure that the intake manifold and throttle body mounting bolts/nuts are securely tightened. Make sure the vacuum hoses are securely connected and in good condition. With the engine running, check the hoses for leaks by listening to them with a stethoscope, which can be a piece of old brake hose. When you bring a stethoscope to the leak, you will hear a hissing sound. You can also apply a soap solution to the hoses to check for leaks.
2. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
3. The crankcase ventilation hose or valve is restricted (chapter 6).
4. The air filter element is clogged (chapter 1).
5. There is not enough fuel being supplied from the pump to the injectors (chapter 4).
6. Depressurization of the cylinder head joint. Perform a compression test in the cylinders (chapter 2B).
7. Wear of camshaft cams (chapter 2).
9 Engine idle speed is reduced
1. Worn spark plugs or incorrect setting of the interelectrode gap (chapter 1).
2. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
3. Failure of spark plug wires (chapter 1).
4. Depressurization of hose connections or intake manifold. Perform a check.
5. Uneven or low compression in the cylinders. Perform the measurement as described in chapter 2B.
10 Reduced engine speed throughout the entire operating range
1. Clogged fuel filter and/or contaminated fuel system (chapter 1).
2. Incorrect setting of the interelectrode gap or failure of the spark plugs (chapter 1).
3. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
4. Failure of spark plug wires (chapter 1).
5. Malfunction of exhaust system components (chapter 6).
6. Uneven or low compression in the cylinders. Remove the spark plugs and use a compression tester to measure (Chapter 2B).
7. Depressurization of the intake manifold, throttle body or vacuum hoses (see subsection 8).
11 The engine stalls
1. Clogged fuel filter and/or clogged/moisture ingress into the fuel system (chapter 1).
2. Failure of sensors or a malfunction in the fuel system (chapter 4 and 6).
3. Malfunction of exhaust system components (Chapter 6).
4. Incorrect setting 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 the fuel system or ignition system components (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. Brakes sticking (chapter 9).
5. Incorrect transmission fluid level in the automatic transmission (chapter 1).
6. Clogging of the fuel filter and/or fuel system components (chapter 1).
7. Malfunction of the exhaust toxicity control system (chapter 6).
8. Use of fuel that does not meet technical requirements. Fill with fuel of the required standard.
9. Low or uneven compression in engine cylinders. Perform a compression test, which can determine whether there is a gas leak through the valves or if the cylinder head gasket is faulty (chapter 2).
10. Restriction of the intake or exhaust system capacity (chapter 4).
13 Reverse flares occur
1. Malfunction of the exhaust toxicity control system (chapter 6).
2. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
3. Malfunction of the secondary circuit of the ignition system (cracking of the insulator or failure of the spark plug wiring) (chapter 1 and 5).
4. Malfunction of injection system elements (chapter 4).
5. Depressurization of the throttle body, intake manifold or vacuum hoses. Perform a check.
6. Valves sticking (chapter 2).
14 Engine rattles or detonates when revving or loading increases
1. Refueling with fuel of inappropriate characteristics. Fill your vehicle with fuel of the appropriate octane rating.
2. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
3. Installation of the wrong type or damage to spark plugs/their wires. Check that the correct spark plug type is installed using the Vehicle Engine Identification Number (VECI) plate located in the engine compartment. Also inspect the spark plugs and their wires (Chapter 1).
4. Malfunction of the exhaust toxicity control system (chapter 6).
5. Depressurization of elements. Perform a check.
15 The engine continues to run after the ignition is turned off
1. Malfunction of the fuel system or ignition system components (chapter 4 or 5).
2. Increased engine operating temperature. This may have happened due to a drop in coolant level (chapter 1), failure of the thermostat, clogging of the radiator or breakdown of the cooling system pump (chapter 3).