Compression Check: Testing and Inspection

TO TEST COMPRESSION PRESSURE:

Disconnect Coil Primary Lead:

1. Disconnect electric cable from connection 1 on ignition coil.

CAUTION: On vehicles with electronic and transistorized ignition systems, connection 1 must be disconnected at the ignition coil. If ignition system is not disconnected, ignition voltage sparkover may result. This can cause damage to ignition system control unit, ignition system or other electrical components.

2. Remove spark plugs.

Compression Tester:

3. Measure compression, with engine hot and throttle fully opened.

Min value: 0.9 MPa (128 psi).
Max difference: 0.2 MPa (28 psi).

Note: Applies to hot engine, fully open throttle and cranking with starter motor, 4.2-5.0 r/s (250-300 rpm).

4. Install spark plugs, torque to: 25±5 Nm (18±4 ft lbs).

NOTE: Results may be influenced by:
- low battery voltage (affects starter motor speed).
- tolerances in different measuring equipment.
- carbon deposits in combustion chambers.