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Home >> Acura >> 2020 >> RLX Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> Engine Control Systems >> Engine Control System / Engine Mechanical - Service, Testing & Troubleshooting (Except Hybrid) >> Inspection >> Engine Compression >> Inspection
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Engine Compression: Inspection

NOTE: After this inspection, you must reset the PCM. Otherwise, the PCM will continue to stop the injectors from operating.
  1. Engine - Warm Up

    Start the engine. Hold the engine speed at 3000 RPM with no load (in P or N) until the radiator fan comes on, then let it idle.

  2. HDS DLC - Connect
    NOTE: For specific operations, refer to the user's manual that came with the HDS. Make sure the HDS is loaded with the latest software.

    1. Turn the vehicle to the OFF (LOCK) mode.

    2. Connect the HDS to the DLC

    3. Turn the vehicle to the ON mode.

    4. Make sure the HDS communicates with the vehicle. If it does not communicate, go to the DLC circuit troubleshooting

    .
  3. All INJECTOR STOP - Select
    1. Select ALL INJECTORS STOP in the PGM-FI INSPECTION menu with the HDS.

    2. Turn the vehicle to the OFF (LOCK) mode.
  4. Ignition Coil and Spark Plug - Remove

    Remove the six ignition coils and the six spark plugs .

  5. Engine Compression - Inspect
    GHH345715Courtesy of HONDA, U.S.A., INC.
    		 1. Attach a compression gauge to the spark plug hole.

    2. 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 930 kPa (9.48 kgf/cm 2, 134.8 psi) 
    GHH345715Courtesy of HONDA, U.S.A., INC.

    3. Measure the compression on the remaining cylinders.
    Maximum Variation: 
    Within 200 kPa (2.04 kgf/cm 2, 29.0 psi) 
    GHH345715Courtesy of HONDA, U.S.A., INC.

    4. 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 gasket
    • Damaged or worn piston rings
    • Damaged or worn piston and cylinder bore

    5. Remove the compression gauge from the spark plug hole.
  6. Ignition Coil and Spark Plug - Install

    Install the six spark plugs and the six ignition coils .

  7. All INJECTOR STOP - Cancel

    Select PCM reset  in the PGM-FI mode menu to cancel ALL INJECTORS STOP with the HDS.

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