Compression Check: Testing and Inspection
CHECKING COMPRESSION PRESSURE1. Warm up the engine.
2. Turn the ignition switch OFF.
3. Perform the Fuel Pressure Release Procedure.
4. Remove all of the spark plugs.
^ Clean area around plug with compressed air before removing the spark plug.
5. Disconnect the camshaft position sensor harness connector at the distributor.
6. Remove the fuel injector fuse No. 3 on FUSE BLOCK (J/B) behind the driver side instrument lower panel.
7. Attach a compression tester to the No. 1 cylinder as shown.
8. Depress the accelerator pedal fully to keep the throttle valve wide open.
9. Crank the engine and record the highest gauge indication.
10. Repeat the measurement on each cylinder.
^ Always use a fully-charged battery to obtain specified engine speed.
Compression: kPa (kg/cm2, psi)/300 rpm
Standard: 1,226 (12.5, 178)
Minimum: 1,030 (10.5, 149)
Difference limit between cylinders: 98 (1.0, 14)
11. If the compression in one or more cylinders is low:
a. Pour a small amount of engine oil into the cylinders through the spark plug hole.
b. Retest the compression.
^ If adding oil improves cylinder compression, piston rings may be worn or damaged. If so, replace piston rings after checking piston.
^ If pressure stays low, a valve may be sticking or seating improperly. Inspect and repair valve and valve seat. If valve or valve seat is damaged excessively, replace it.
^ If compression in any two cylinders adjacent cylinders is low, and if adding oil does not improve compression, there is leakage past the gasket surface. If so, replace cylinder head gasket.
12. Reinstall the spark plugs, fuel injector fuse, fuel pump fuse, and reconnect camshaft position sensor harness connector at the distributor.
13. Erase the DTC stored in the ECM.
CAUTION: Always erase the DTC after checking compression.