If the engine runs poorly or intermittently, check the ignition system and fuel system. If the reasons for poor engine performance cannot be found, perform a compression test.
Regularly performing this check will also allow you to prevent the occurrence of malfunctions in advance.
Procedure
1. Check the engine oil level. Make sure the starter is working properly and the battery is fully charged.
2. Start the engine and warm it up to a temperature of 80–95°C.
3. Turn off the engine and remove the high-voltage wire tips from the spark plugs.
4. Remove the spark plugs.
5. Turn the engine crankshaft.
6. Screw the compression tester tip into the spark plug hole.
7. Open the throttle valve fully.
8. Using the starter, turn the engine crankshaft approximately 4 revolutions and determine the compression using the instrument scale. Compression: 1500 kpa Minimum allowable compression: 1400 kpa.
9. Repeat steps 6–8 on the remaining cylinders, making sure that the pressure difference for each cylinder is within acceptable limits. Permissible pressure difference in engine cylinders: 100 kpa.
10. If compression is low in all cylinders, pour a few drops of motor oil into each cylinder through the spark plug holes and repeat steps 6–9.
- If adding oil increases compression, the piston rings may be worn out.
- If the compression remains at the same level, the valves may be burnt or the cylinder head gasket may be damaged.
- Screw in the spark plugs and connect the high-voltage wires to them. Spark plug tightening torque: 20–30 Nm