Compression test
1. Warm up the engine well. Then mute it.
2. Relieve fuel pressure trace, arr:
- A. Remove the rear seat assembly.
- b. Open the hatch cover
- With. Disconnect the connector from the fuel level sensor, fuel filter and fuel pump assembly and start the engine. See chapter Accelerator, fuel system and exhaust system.
- d. After the engine stalls, crank it two or three times and relieve all fuel pressure.
Caution: After relieving fuel pressure and until the compression test is completed, leave the connector disconnected.
3. Remove the ignition coils and remove the spark plugs from all cylinders. See sections «Ignition coil» And «Spark plug (with platinum tip)».
4. Connect the tachometer (not required when using the CONSULT-II tester).
5. Screw in the compression gauge (1) into the spark plug hole using an adapter.
Diameter 20 mm.
Use a compression gauge adapter with a tip diameter of less than 20 mm. Otherwise, when turning out, it may get stuck in the cylinder head.
6. Fully depress the accelerator pedal, turn the ignition key to the «START» and check the crankshaft. When the arrow of the compression gauge calms down, read the compression pressure and engine speed. Repeat measurements on all cylinders.
kPa (kg/cm2) /350 rpm
Engine | CR14DE |
Standard | 1383 (14,1) |
Minimum | 1187 (12,1) |
Limit dispersion between cylinders | 98 (1,0) |
Caution: Always use a fully charged battery to achieve the desired engine speed.
If the engine speed is abnormal, check the specific gravity of the electrolyte in the battery. Check engine speed again with normal electrolyte density.
If the compression pressure is below the minimum value, check the valve clearances and components associated with the combustion chamber (valve, valve seat, piston, piston ring, cylinder wall, cylinder head, cylinder head gasket). After checking, measure the compression again.
If compression is low in some cylinders, pour a small amount of engine oil into the spark plug hole of that cylinder and recheck the compression.
If compression increases after adding engine oil, piston rings may be worn or damaged. Check piston rings and replace if necessary.
If, despite the addition of engine oil, the compression pressure remains low, the valves may be faulty. Check for damaged valves. Replace valve or valve seat, respectively.
If two adjacent cylinders have low compression pressure and remain low even after adding engine oil, there is a gasket leak. In this case, replace the cylinder head gasket.
7. Upon completion of the check, install the removed components in the reverse order of removal.