lemon-mirror:
Home >> Acura >> 2012 >> ZDX >> Repair and Diagnosis >> Engine Mechanical >> Mechanical >> Cylinder Head >> Engine Compression Inspection

Engine Compression Inspection

NOTE: After the inspection, you must reset the PCM. Otherwise, the PCM will continue to stop the fuel injectors from operating.
  1. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  2. Connect the HDS to the DLC (see HOW TO USE THE HDS (HONDA DIAGNOSTIC SYSTEM) ).
  3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  4. Make sure the HDS communicates with the vehicle and the PCM. If it does not communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
  5. Select ALL INJECTORS STOP in the PGM-FI INSPECTION menu with the HDS.
  6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  7. Remove the six ignition coils and the six spark plugs (see IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION ).
  8. Attach the compression gauge to a spark plug hole.
    Fig 1: Attaching Compression Gauge To Spark Plug Hole
    G08075084Courtesy of AMERICAN HONDA MOTOR CO., INC.
  9. Step on the accelerator pedal to open the throttle fully, then crank the engine with the starter motor, and measure the compression.
    NOTE: The auto-start function cranks the engine until it starts, or for 15 seconds if the engine does not start.

    Compression Pressure: 

    Above 930 kPa (9.48 kgf/cm 2  , 134.8 psi) 

  10. Measure the compression on the remaining cylinders.

    Maximum Variation: 

    Within 200 kPa (2.04 kgf/cm 2  , 29.0 psi) 

  11. 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 camshaft timing
    • Damaged or worn cam lobes
    • Damaged or worn valves and seats
    • Damaged cylinder head gaskets
    • Damaged or worn piston rings
    • Damaged or worn piston and cylinder bore
  12. Remove the compression gauge from the spark plug hole.
  13. Install the six spark plugs and the six ignition coils (see IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION ).
  14. Select PCM reset (see IF THE MIL DID NOT STAY ON ) in the PGM-FI INSPECTION menu to cancel ALL INJECTORS STOP with the HDS.
· About lemon-mirror