Compression Inspection
WARNING:
- Hot engines and oil can cause severe burns. Be careful not to burn yourself during removal/installation of each component.
- Fuel vapor is hazardous. It can very easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
- Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the "Fuel Line Safety Procedure". (See BEFORE SERVICE PRECAUTION .)
- Verify that the battery is fully charged. (See BATTERY INSPECTION
.)
- Recharge it if necessary. (See BATTERY RECHARGING .)
- Connect the M-MDS to the DLC-2.
- Warm up the engine to the normal operating temperature.
- Display the following PIDs using the M-MDS data monitor function. (See PCM INSPECTION
.)
- RPM (engine speed)
- Perform "Fuel Line Safety Procedures". Leave the fuel pump relay removed. (See BEFORE SERVICE PRECAUTION .)
- Remove the plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION .)
- Remove the fuel pump relay. (See BEFORE SERVICE PRECAUTION .)
- Remove the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION .)
- Remove the spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION .)
- Measure the compression pressure using the following procedure.
- Install the compression gauge to the spark plug hole.
- Fully depress the accelerator pedal.
- Crank the engine and measure the following values simultaneously.
- Compression pressure
- Engine speed
- Compression pressure
Standard: Refer to the graph.
Minimum: Refer to the graph.
Maximum difference between cylinders: 196.1 kPa {2.0 kgf/cm2 , 28.5 psi}
- Perform Steps 1 to 3 for all cylinders.
- If the measured value is the threshold or less, or if there is a cylinder which exceeds the specified maximum difference between cylinders, add a small amount of engine oil through the spark plug hole and perform Steps 1 to 3.
- If the pressure increases by adding the engine oil, the piston ring or the cylinder surface is worn, or they are damaged. Perform overhaul servicing.
- If the pressure does not increase, valve seizure, valve attachment malfunction, or pressure leakage from the cylinder head gasket might be occurring. Perform overhaul servicing.
- Remove the compression gauge.
- Install the following parts.
- Spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION .)
- Ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION .)
- Fuel pump relay. (See BEFORE SERVICE PRECAUTION .)
- Plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION .)