2. Remove all ignition coils and remove spark plugs.
3. Disconnect the electrical connector from the crank angle sensor (pic. 2.8)
Pic. 2.8. Crankshaft Position Sensor Connector Location
Note. Disconnecting the connector from the crankshaft position sensor will disable the ignition system and the fuel injection system.
4. When turning the crankshaft with a starter, cover all spark plug holes with a towel or cloth. After cranking the crankshaft with the starter, check for impurities adhering to the towel.
Warning
(1) When checking compression, do not stand in front of the spark plug holes.
(2) If during the measurement of compression in the cylinder (as a result of cracks) If coolant, oil, fuel, etc. gets in, these substances will heat up and be ejected under pressure from the spark plug hole, which can be dangerous.
5. Connect a compression gauge to the spark plug hole of cylinder #1 (pic. 2.9).
Pic. 2.9. Connecting a compression gauge to the spark plug hole
6. Open the throttle and turn the engine crankshaft with the starter. After one or two revolutions, the compression pressure should rise to the maximum mark and then stabilize. Write down the result.
Nominal compression at a crankshaft speed of 300 min-1:1720 kPa
The minimum allowable compression at a crankshaft speed of 300 min-1: 1462 kPa
7. Check up a compression in other cylinders and write down the received indications. The pressure in all cylinders must be the same or differ no more than the permissible value.
Permissible difference in compression and engine cylinders: 100 kPa
8. If the pressure in any cylinder is too low, pour a teaspoon of clean engine oil into the cylinder through the spark plug hole and repeat steps 6 and 7.
(1) If the pressure increases after adding oil, the piston rings and/or cylinder are worn.
(2) If the pressure does not increase, then the cause is worn or burned valves or a blown cylinder head gasket. Low pressure in two adjacent cylinders almost always means that a head gasket is blown between them.
9. Connect the connector to the crankshaft position sensor.
10. Screw in the spark plugs and install the ignition coils.
11. Use the MUT-II to clear diagnostic trouble codes.
Note. The DTC will be cleared as a result of disconnecting the connector from the crankshaft position sensor.