Engine Compression Inspection
NOTE:
After this inspection, you must reset PGM-FI ECU in the PGM-FI INSPECTION menu with the HDS to cancel ALL INJECTORS STOP and STARTER TEST functions.
- Allow the engine to reach operating temperature (fan comes on at least twice).
- Turn the ignition switch to LOCK (0).
- Connect the HDS to the DLC (see step 2 GENERAL TROUBLESHOOTING INFORMATION ).
- Turn the ignition switch to ON (II).
- Make sure the HDS communicates with the vehicle and the PCM. If it do not communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
- Select ALL INJECTORS STOP in the PGM-FI INSPECTION menu with the HDS.
- Select STARTER TEST in the PGM-FI INSPECTION menu with the HDS.
- Turn the ignition switch to LOCK (0).
- Remove the four intake side ignition coils and the four spark plugs (see IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION ).
- Attach the compression gauge to the spark plug hole.
- Step on the accelerator pedal to open the throttle fully, then crank the engine with the starter motor and measure the compression.
Compression Pressure
Above 980 kPa (10.0 kgf/cm 2 , 142 psi)
- Measure the compression on the remaining cylinders.
Maximum Variation:
Within 200 kPa (2.0 kgf/cm 2 , 28 psi)
- If the compression is not within specifications, perform a cylinder leak down test to determine the problem area. Then check the following items, and remeasure the compression:
- Incorrect valve clearance
- Confirmation of cam timing
- Damaged or worn cam lobes
- Looseness of exhaust side spark plug
- Damaged or worn valves and seats
- Damaged cylinder head gasket
- Damaged or worn piston rings
- Damaged or worn piston and cylinder bore
- Remove the compression gauge from the spark plug hole.
- Install the four intake side spark plugs and the four ignition coils (see IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION ).
- Select PGM-FI ECU reset (see IF THE MIL DID NOT STAY ON ) in the PGM-FI INSPECTION menu with the HDS to cancel ALL INJECTORS STOP and STARTER TEST.