Basic Checks for Difficulty Starting the Engine
Petrol models
Evaluate the external condition of all electrical wiring in the engine compartment, make sure that there are no signs of insulation integrity violation, oxidation and loosening of contact connections. Check if there are blown fuses in the mounting block, if the battery is good. Next, you should make sure that the laying is correct, the condition is good and the vacuum hoses are securely fastened. Be sure to also check the intake air duct components for signs of leaks.
If no obvious violations can be detected during a visual inspection, the compression pressure in the engine cylinders should be checked (see Section 2 of Chapter 2).
Another important mechanical check is to check the patency of the engine exhaust tract. Checking is carried out using a pressure gauge or vacuum gauge. In the first case, unscrew the lambda probe, or the control valve of the air mixing system into the exhaust gases (depending on configuration). Screw in place of the removed component a pressure gauge with a measurement range of 0-0.35 kgf / cm2 and start the engine at 2500 rpm, - if the backpressure in the exhaust tract is more than 0.14 kgf / cm2, there is a violation of its patency (most likely, the patency of the catalytic converter is impaired). If using a vacuum gauge, connect it to the intake manifold vacuum fitting, start the engine, and read the gauge. Partially open and lock the throttle - a slow drop in the depth of vacuum after stabilization of the speed will also indicate a violation of the exhaust tract.
At this point in the basic diagnosis, perform the following fuel delivery checks: (see chapter 4).
Note: Most of the checks below must be depressurized before starting most of the checks listed below (see chapter 4).
- Checking the regulated fuel pressure.
- Checking the tightness of the components of the fuel path.
- Checking the fuel pump relay.
- Assessment of the condition of fuel injectors.
First of all, you should make sure that the sparking on the spark plugs is working - it is best to check with a special tester. It is necessary to check the serviceability of the power supply to the ignition coils and measure the resistance of the primary and secondary circuits of the ignition coils.
Diesel models
Among the conditions, the fulfillment of which guarantees the successful start of any diesel engine, include:
- sufficient to start the engine crankshaft speed;
- the temperature of compressed air in the combustion chamber sufficient for self-ignition of fuel, i.e. achievement of the set compression pressure and, when starting in the cold, - the proper functioning of the glow plugs;
- fine spray (injection) fuel into the combustion chambers at exactly the right time.
First of all, you should make sure that the starter is in good condition, then check the fuel supply, nozzles and the operation of the preheat system.
1. The engine does not turn over when trying to start it
1. There is corrosion of the battery terminals, or the fastening of the wire lugs on them has loosened.
2. The battery is discharged or defective: in the absence of violations of the previous paragraph, with the ignition on, turn on the headlights and / or wipers, - the failure of the correct functioning of electrical appliances confirms the fact of an excessive decrease in the battery level.
3. The wiring in the engine starting system circuit is broken or the wires are loose on the terminals.
4. The starter gear is wedged in the ring gear of the drive disk.
5. Defective starter relay.
6. Faulty starter.
7. Faulty ignition switch.
2. Engine cranks but won't start
1. Wrong startup (see chapter "Controls and methods of operation").
2. Faulty or disabled engine immobilizer.
3. Insufficient compression value.
4. Excessively thick oil has been filled into the engine.
Petrol models
5. The fuse of the electric fuel pump or electronic injection system is faulty.
6. The fuel tank is empty or filled with low-quality fuel.
7. The air filter is very dirty.
8. As a result of a leak, air is sucked into the intake tract, and vacuum losses occur in the vacuum tract.
9. There are vacuum losses in the air supply elements, malfunctions in the fuel injection and ignition control system.
10. Low battery (insufficient engine cranking speed).
11. Battery terminal connections are oxidized or loose.
12. The fuel pump is faulty, or its relay is damaged - check by ear that the pump is activated when the ignition is turned on.
13. Damaged or excessively wet components of the ignition system.
14. Worn or defective spark plugs, or incorrect spark plug gap.
15. The electrical wiring of the starting system is broken or disconnected, or the fastening of the wires to the terminals is loose.
16. The electrical wiring of the ignition coil is broken or disconnected, or the fastening of the wires at the coil terminals is loose.
17. The fuse of the engine control unit is damaged, the sensors of the engine management system are faulty.
Diesel models
Note: Make sure that during the operation of the pre-glow system (when K/L preheat is on) all onboard electrical consumers (light, heated rear window, audio system, etc.) were disabled.
18. Electric fuel pump fuse blown (in the presence of) or preheat systems.
19. The preheat does not work. Check.
20. There is no voltage on the fuel cutoff solenoid valve, or the solenoid valve is defective.
21. There is damage in the fuel supply lines, or air has entered the latter.
22. The patency of the return fuel path is broken.
23. Clogged fuel filter.
24. The adjustment of the moment of the start of the fuel supply is knocked down.
25. Faulty injectors, - when the union nut of the fuel line of the faulty injector is loosened, the engine speed will not drop.
26. Faulty high pressure fuel pump (injection pump).
3. The starter operates without cranking the engine
1. Stuck starter gear.
2. Worn or damaged starter gear teeth or flywheel crown.
4. Difficulty starting a cold engine
1. The battery is discharged or its charge level is insufficient.
2. The serviceability of the functioning of the components of the power system or electrical equipment is broken.
3. There is a deposition of paraffin in the fuel fine filter (diesel models), - warm up, or replace the filter element and fill the car with winter diesel fuel, or add low-octane gasoline to the tank in a ratio of 1/3.
4. Faulty diesel engine glow plugs.
5. Difficulty starting a hot engine
1. Air filter clogged.
2. The serviceability of the functioning of the components of the power system or electrical equipment is broken.
3. Fuel is not supplied to the injectors / nozzles of the injection system.
4. The fuel advance angle of the diesel engine has gone astray.
5. Faulty injection pump of a diesel engine, or its adjustment is violated.
6. Insufficient compression pressure.
6. Starter engagement is too noisy or difficult
1. Worn or damaged starter gear teeth or flywheel crown.
2. Lost starter fasteners, or weakened the tightening force.
7. The engine starts, but immediately stalls
1. Faulty engine immobilizer.
2. The wiring is faulty, or the wires are loose at the terminals of the ignition coil or generator.
3. There is a malfunction of the functioning of the components of the power system or electrical equipment.
4. The basic settings of the engine control module are violated (ECM).
5. There is damage in the exhaust system/catalytic converter.
6. Vacuum loss occurs at the throttle body, intake manifold, or through the vacuum hoses.
7. Insufficient compression pressure.
8. Idle speed adjustment is broken.
9. The patency of the return fuel path of the diesel engine is broken.
10. Too early shutdown of diesel engine glow plugs.
11. The fuel advance angle of the diesel engine has gone astray.
12. Faulty injection pump.
13. The e / m valve for cutting off the fuel supply of the diesel engine is jammed.
8. The stability of the engine at idle is broken
Note: At unstable engine speeds (e.g. misfires) To avoid failure of the catalytic converter, try to run the engine only for a short time and avoid excessive loads.
Petrol models
1. There are vacuum losses. Make sure that the fasteners are securely tightened, check the fact and quality of fastening on your fittings on the inlet pipeline of all vacuum hoses. Listen to the running engine with a stethoscope or a piece of fuel hose. The presence of a hissing sound will reveal the source "leaks" vacuum, - no less effectively you can use a solution of soapy water to check.
2. The tightness of the landing of the inlet pipeline on the cylinder head is broken.
3. Broken cylinder head gasket - measure the compression pressure in the engine cylinders (see chapter 2).
4. Worn timing drive components.
5. Camshaft lobes worn out.
6. Engine overheated.
7. The patency of the PCV system valve is disturbed.
8. There are leaks through the EGR valve.
9. There is a malfunction of the functioning of the components of the power system or electrical equipment.
10. The patency of the air filter is broken.
11. The fuel pump is not supplying enough fuel to the injectors.
Diesel models
12. The quality of the connections of the fuel hoses on the injection pump and the fuel filter is broken.
13. Loose injection pump mounting.
14. The connections of the return pipeline and the fuel supply pipeline are reversed.
15. There is damage in the fuel lines.
16. The patency of the return fuel path is broken.
17. Adjustment of turns of a slow idling is broken.
18. Air has entered the power system.
19. The adjustment of the start of the fuel supply is knocked down.
20. Faulty injectors, - when the union nut of the fuel line of the faulty injector is loosened, the engine speed will not drop.
21. Faulty injection pump. Install a new or known-good injection pump for testing.
9. There are gaps in the operation of the cylinders at idle
Note: At unstable engine speeds (e.g. misfires) To avoid failure of the catalytic converter, try to run the engine only for a short time and avoid excessive loads.
1. Worn or dirty spark plugs or incorrect spark plug gap.
2. There is a malfunction of the components of the power system or electrical equipment.
3. Low-quality fuel is filled, or the fuel filter is blocked.
4. There is a loss of vacuum in the intake manifold or through the hose connections.
5. Insufficient or unevenly distributed compression pressure in the cylinders.
6. There are violations in the operation of the engine management system.
10. There are misfires in the operation of the engine cylinders at exceeding idle speeds / when the vehicle is moving in gear
Note: At unstable engine speeds (e.g. misfires) To avoid failure of the catalytic converter, try to run the engine only for a short time and avoid excessive loads.
1. The fuel filter is clogged, or the fuel path is blocked.
2. Faulty or dirty spark plugs, or incorrect spark plug gap (gasoline engines).
3. Faulty components of the power system or electrical equipment.
4. Components of systems of decrease in toxicity OG are faulty.
5. Insufficient or unevenly distributed compression pressure between the cylinders.
6. Faulty ignition system.
7. Vacuum loss occurs at the throttle body, intake manifold, or through the vacuum hoses.
8. Worn valve train.
9. Timing phase adjustment is broken.
10. The patency of the inlet pipeline is broken.
11. The adjustment of the start of the diesel engine fuel supply is knocked down.
12. The car is filled with diesel fuel of poor quality.
11. Engine spontaneously stalls
1. Idle speed adjustment is broken.
2. The patency of the fuel filter is broken, or moisture or dirt has got into the power system.
3. There is a failure of the components / information sensors of the engine management system.
4. Components of systems of decrease in toxicity OG are faulty.
5. Faulty or dirty spark plugs or incorrect spark plug gap (see chapter 1).
6. There are vacuum losses at the throttle body or through the vacuum hoses.
12. The engine does not develop full power
1. There is a malfunction of the components of the power system or electrical equipment.
2. The air cleaner is clogged, or the patency of the intake air path is otherwise impaired.
3. Faulty spark plugs or incorrect spark plug gap (gasoline engines).
4. Faulty coil (-And) ignition.
5. Blocked fuel filter and/or dirt/moisture in the fuel system.
6. Wrong grade of fuel filled.
7. Damaged turbocharger control valve (with appropriate equipment).
8. Insufficient compression pressure, or its uniform distribution between the cylinders is broken.
9. Stuck valves or weak valve springs.
10. Blown cylinder head gasket.
11. Clutch slips.
12. Engine overheated.
13. There are vacuum losses.
14. Camshaft lobes worn out.
15. The installation of the gas distribution phases is violated.
16. There are leaks in the fuel pump.
17. Passability of system of release OG is broken.
Optional for diesel engine
18. Faulty EGR valve.
19. The adjustment of the maximum speed of the crankshaft is broken.
20. Clogged fuel filter, injection pump or injectors.
21. The patency of the fuel path in the area between the high-pressure fuel pump and the fuel tank is broken.
22. The patency of the return fuel line is broken.
23. The uniformity of the fuel supply to the cylinders is broken.
24. Incorrectly set the moment of the beginning of the fuel injection pump.
13. There are pops in the intake system or shots in the exhaust system
1. The functioning of the components of the power system or electrical equipment is broken.
2. There is a defect in the secondary circuit of the ignition system of a gasoline engine (destruction of spark plug insulators).
3. The fuel injection system needs to be adjusted, or its components are excessively worn.
4. There is vacuum loss at the throttle body, intake piping, or through the vacuum hoses.
5. Stuck valves.
6. Violated setting of the ignition timing.
7. Faulty EGR valve.
8. A lean air-fuel mixture enters the cylinders.
14. Detonation sounds occur when accelerating or going uphill
1. Poor quality fuel filled.
2. The functioning of the components of the power system or electrical equipment is broken.
3. Wrong type of spark plugs installed (gasoline engines).
4. The basic settings of the ECM are violated.
5. Faulty knock sensor.
6. There are vacuum losses.
15. The engine continues to run after the ignition is turned off
1. Excessively high idle speed.
2. There is a malfunction of the electrical equipment, control components or fuel cut-off valve (diesel models).
3. Serviceability of functioning of the e/m valve of a purge of an adsorber of the EVAP system is broken.
4. Excessively high engine operating temperature (low coolant level, thermostat failure, radiator blockage, or water pump failure).
16. Excessively smoky diesel engine exhaust
1. Black smoke:
- the air cleaner is dirty, - wash or replace the filter element;
- incorrect fuel is filled, - flush the tank and change the fuel;
- the moment of the start of the injection pump supply is incorrectly set, or the pump itself is faulty;
- injector valve leak. Check the operation of the injectors on the stand, if necessary, disassemble and grind the valve, or replace the injector assembly;
- Faulty EGR valve.
2. Blue smoke:
- oil enters the chamber (-s) combustion due to wear of the piston rings, its presence in the air cleaner, wear of the seals in the turbocharger covers, the formation of leaks in the gasket between the crankcase and the turbocharger - repair the engine, replace the seals, tighten the turbocharger mounting bolts or replace the gasket;
- the fuel supply to one of the nozzles is disrupted - check by heating the exhaust pipes of the manifold;
- the quality of fuel atomization by the injector is impaired due to a malfunction of the valve or a break in the atomizer - lap the valve or replace the injector.
3. White or brown smoke:
- insufficient coolant temperature, - check the thermostat;
- malfunction of the nozzles due to wear or breakage of the atomizer - replace the atomizer.