COMPRESSION PRESSURE CHECK


1.Before inspection, set the vehicle to the pre-inspection condition.

2.Remove all of the spark plugs.
3.Disconnect the crank angle sensor connector.
note Doing this will prevent the engine-ECU from carrying out ignition and fuel injection.
caution
  • Keep away from the spark plug hole when cranking.
  • If compression is measured with water, oil, fuel, etc., that has come from cracks inside the cylinder, these materials will become heated and will gush out from the spark plug hole, which is dangerous.
4.Cover the spark plug hole with a shop towel etc., and after the engine has been cranked, check that no foreign material is adhering to the shop towel.
5.Set compression gauge to one of the spark plug holes.

6.Crank the engine with the throttle valve fully open and measure the compression pressure.
Standard value (at engine speed of 200 r/min):
    1,710 kPa
Limit (at engine speed of 200 r/min):
    Minimum 950 kPa
7.Measure the compression pressure for all the cylinders, and check that the pressure differences of the cylinders are below the limit.
Limit: Maximum 98 kPa
8.If there is a cylinder with compression or a compression difference that is outside the limit, pour a small amount of engine oil through the spark plug hole, and repeat the operations in steps from 6 to 8.
(1) If the compression increases after oil is added, the cause of the malfunction is a worn or damaged piston ring and/or cylinder inner surface.
(2) If the compression dose not rise after oil is added, the cause is a burnt or defective valve seat, or pressure is leaking from the gasket.
9.Connect the crank angle sensor connector.
10.Install the spark plugs.
11.Use the M.U.T.-III to erase the diagnosis codes.
note This will erase the diagnosis code resulting from the crank angle sensor connector being disconnected.