Engine Diagnostics

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1. Engine won't crank when trying to start it


1. The battery terminals are oxidized or not connected. Check battery wires. Get tight contact, clean them if necessary.

2. The battery is low or defective. If the wire terminals are clean and firmly connected to the battery terminals, turn on the ignition and check the operation of the headlights or wiper. If they don't work, the battery is dead.

3. The automatic transmission lever is not set to the position "Parking" or "neutral".

4. Breakage or break in the starter circuit. Check all wires and contacts of the battery, ignition circuits and starter relay.

5. The gear of the starter bendix rested on the ring gear of the flywheel. If the transmission is manual, shift into gear and roll the car so that the engine cranks. Remove the starter, inspect the gear and flywheel (chapter 5).

6. Faulty starter relay (chapter 5).

7. Faulty starter motor (chapter 5).

8. Faulty ignition switch (chapter 12).

2. Engine cranks but won't start


1. There is no gasoline in the tank.

2. Faulty fuel injection system (chapters 4 and 5).

3. Battery low (motor turns slowly).

4. Check the wiring as recommended in the previous section. Battery terminals oxidized (see previous section).

5. Faulty injection or fuel pump (chapter 4).

6. Damp or damaged ignition system (chapter 5).

7. Worn, faulty or incorrectly installed spark plugs (Chapter 1).

8. Breakage, looseness of connection of contacts or break in the starter circuit (see previous section).


9. The distributor failed by changing the ignition timing. Turn the distributor to start the engine, then immediately set the correct ignition timing (chapter 5).

10. Breakage, looseness in the connection of contacts or a break in the circuit of the ignition coil, a malfunction of the coil itself (chapter 5).

3. The engine does not start when the starter is running


1. Stuck starter gear. Take out the starter (chapter 5) and inspect.

2. Starter gear or flywheel teeth worn or broken. Open the flywheel/drive plate access cover in the oil pan and inspect.

4. Difficult to start a cold engine


1. The battery is low or low. Check as stated in section 1.

2. Malfunction in the fuel injection system (chapters 4 and 5).

3. The fuel injection system requires a bulkhead (chapter 4).

4. Distributor rotor dirty and/or broken (chapters 1 and 5).

5. Difficulty starting a hot engine


1. Clogged air filter (Chapter 1).

2. Faulty fuel injection system (chapters 4 and 5).

3. Fuel does not enter the injection system (see section 2).

6. Starter makes noise when turned on


1. Gear or flywheel teeth worn or broken. Open the cover on the back of the engine (at the right location) and inspect.

2. The bolts securing the starter are loose.

7. The engine starts and immediately stalls


1. Leakage of electrical contacts or breakdown in the distributor. ignition coil or alternator.

2. Breakdown of the fuel injection system (chapters 4 and 5).

3. Not enough fuel enters the injector. Check fuel pressure (chapter 5).


4. Vacuum drop in the intake manifold due to leaks through the seals, fuel injection unit or throttle. Make sure that all mounting bolts and nuts are tightly tightened and that the vacuum hoses leading to the fuel injection unit are correctly installed and in working order.

8. Engine idling unevenly, idling is unstable


1. Vacuum drop. Check the fasteners of the fuel injection unit and the intake manifold for tightness. Make sure all piping is connected and intact. With the engine running, you can listen to the vacuum drop with a stethoscope. You will hear a whistling sound. Check the injector and intake manifold for tight sealing.

2. Malfunction in the injection system (chapter 4 and 5).

3. EGR valve leaks or PCV valve blockage (see chapters 1 and 6).

4. Clogged air filter (Chapter 1).

5. The fuel pump does not give the performance required for injection chapter 4).

6. The fuel injection system is depressurized (chapter 4).

7. Leaks through the cylinder head gasket.

8. Timing chain or sprocket worn (chapter 2).

9. Camshaft lobes worn out (chapter 2).

9. Interruptions in idling of the engine


1. Spark plugs worn or incorrectly installed (Chapter 1).

2. Malfunction in the fuel injection system (chapters 4 and 5).

3. Bad spark plug wires (Chapter 1).

10. Interruptions in the working stroke of the engine


1. Clogged fuel filter and/or contamination in the fuel system (Chapter 1).

2. Uncorrected or improperly installed spark plugs (Chapter 1).

3. Faulty fuel injection system (chapters 4 and 5).


4. Incorrect ignition timing (chapter 5).

5. Cracked distributor cap, disconnected wires, or damaged distributor (chapter 5).

6. Leaks through spark plug wires (Chapter 1).

7. Faulty exhaust system (chapter 6).

8. Compression pressure in the cylinders is low or absent. Remove the spark plugs and check the pressure with a gauge (chapter 2).

9. Weak or faulty ignition system (chapter 5).

10. Vacuum loss in the fuel injection system, intake manifold or supply lines (see section 8).

11. Engine stalls


1. Abnormal idle speed. Look at the VECI label and chapter 4.

2. Clogged fuel filter and/or water and contamination in the fuel supply system (Chapter 1).

3. Distributor elements damp or damaged (chapter 5).

4. Faulty injection system or sensors (chapter 4 and 5).

5. Faulty elements of the exhaust system (chapter 6).

6. Faulty or incorrectly installed spark plugs (Chapter 1). Check high voltage wires (Chapter 1).

7. Vacuum drop in injector assembly, intake manifold or vacuum hoses (see section 8).

12. Engine loses power


1. Ignition timing incorrectly set.

2. Faulty fuel injection system (chapters 4 and 5).

3. Distributor shaft play is too great. Also check if the rotor, distributor cap, wires, etc. are broken. (chapter 1 and 5).

4. Faulty or incorrectly installed spark plugs (Chapter 1).

5. Incorrectly adjusted or worn fuel injection system (chapter 4).

6. Faulty ignition coil (chapter 5).

7. Stuck brake (Chapter 1).

8. The fluid level in the automatic transmission is not normal (Chapter 1).


9. Clutch slipping (chapter 8).

10. Fuel filter clogged and/or dirt in the fuel system (Chapter 1).

11. The exhaust control system does not work (chapter 6).

12. Use non-standard fuel, fill the tank with the correct brand of fuel.

13. Compression pressure in the cylinders is low or absent. Check with a compression gauge, which can detect leaking valves and/or a blown head gasket (chapter 2).

13. Engine gives reverse start


1. The exhaust system is faulty (chapter 6).

2. Malfunctions in the ignition system (chapter 4 and 5).

3. Ignition timing incorrectly set (chapter 5).

4. Faulty secondary ignition circuit (broken spark plug insulator, problems with spark plug wires, distributor cap and/or runner (chapters 1 and 5)).

5. Injection unit needs adjustment or is badly worn (chapter 4).

6. Vacuum drop in injection unit, intake manifold or vacuum hoses (see section 8).

7. Valve sticking (chapter 2).

14. Detonation or knocking in the engine when accelerating or climbing


1. Wrong brand of fuel. Fill the tank with gasoline of the correct octane rating.

2. Faulty fuel injection system (chapter 4 and 5).

3. Ignition timing incorrectly set (chapter 5)

4. Need to adjust the fuel injection unit (chapter 4).

5. Candles of a different brand. Check the type of spark plugs on the tag installed in the engine compartment. Check if the integrity of the candles and wires is broken (Chapter 1).

6. Worn or damaged elements of the ignition distributor (chapter 5).

7. Malfunctions in the exhaust system (chapter 6).

8. Vacuum drop (see section 9).

15. The engine continues to run when the ignition is off


1. High idle.

2. Malfunction of the fuel injection system (chapters 4 and 5).

3. Incorrectly adjusted ignition timing (chapter 5).

4. Engine operating temperature too high. Possible Causes - Faulty thermostat, clogged radiator, inoperative water pump (chapter 3).







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