compression ratio MITSUBISHI LANCER EVOLUTION IV 1998 Workshop Manual

ENGINE – Engine Adjustments11-6
(3) If the noise is not eliminated by racing, follow these steps
to check the lash adjuster.
a. Stop the engine.
b. Bring no. 1 cylinder to TDC on the compression stroke.
c. Push the rocker arms indicated by arrow A on the
left to see if they go down.
d. Slowly turn the crankshaft clockwise 360
.
e. Perform the same step as step c for rocker arms
indicated by arrow B.
f. Push the part of the rocker arm which contacts the
top of the lash adjuster. If the rocker arm can be
easily moved down to the bottom, the lash adjuster
is defective, requiring replacement.
When the lash adjuster is replaced, be sure first to
bleed the lash adjuster of air before installation. Then,
perform steps a through e to ensure that no abnormal
symptoms are noted.
NOTE
(1) The leak-down test is an effective means to
accurately determine if the lash adjuster is
operational or not.
(2) For the leak-down test and bleeding procedures,
refer to ENGINE WORKSHOP MANUAL.
If the rocker arm is felt binding and cannot be
pushed downward as you push it, the lash adjuster
is operational. Check for other possible causes
for the noise.
(4) Lash adjuster replacement
Caution
From the cylinder from which the lash adjuster is
to be removed, turn the crankshaft to lower the piston,
as the valve contacts the piston when pushed down.
A rocker arm cannot be removed if it is lifted by the
cam. If this is the case, turn the crankshaft so that
the arm is not lifted.
a. Using the special tool, push the valve downward to
remove the roller rocker arm.
b. Remove the lash adjuster from the cylinder head.
c. Mount a brandnew lash adjuster which has been bled
of air in the cylinder head.
d. Using the special tool, lower the valve and install
the roller rocker arm.
NOTE
To mount the roller rocker arm, first place the pivot
side of the rocker arm on the lash adjuster, then push
down the valve; next, place the slipper side of the
rocker arm on the valve system side.Timing belt side
ABABAA B B
MD998782
MD998782

ENGINE – Engine Adjustments11-8
(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
2
Limit (at engine speed of 250 r/min): 9.7 kg/cm2
(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
2
(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}
Compression gauge
Vacuum gauge
Fuel pressure
regulator valve