Manifold Vacuum Check - Mitsubishi LANCER EVOLUTION-IV 1998 Workshop Manual

11-8
Compression gauge
Vacuum gauge
Fuel pressure
regulator valve
ENGINE –
Engine Adjustments
(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 250 r/min): 11.5 kg/cm
Limit (at engine speed of 250 r/min): 9.7 kg/cm
(7) Measure the compression pressure for all the cylinders,
and check that the pressure differences of the cylinders
are below the limit.
Limit: Max. 1.0 kg/cm
(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 (5) through (7).
a. 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.
b. If the compression does 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)Install the ignition coil and connect the ignition coil
connector.
(12)Erase the diagnosis codes by keeping the battery minus
(–) cable disconnected for more than 10 seconds.
NOTE
This will erase the diagnosis code resulting from the crank
angle sensor connector being disconnected.

8. MANIFOLD VACUUM CHECK

(1) Before inspection, set the vehicle to the pre-inspection
condition.
(2) Connect a tachometer connector.
(3) Attach a three-way union to the vacuum hose between
the fuel pressure regulator valve and the intake manifold,
and connect a vacuum gauge.
(4) Start the engine and check that idle speed is within
standard value.
Standard value: 850 ± 50 r/min
5. Check the manifold vacuum at idling.
Limit: Min. 55 kPa {410 mmHg}
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