1990 MITSUBISHI ECLIPSE oil

ENGINE- Base Engine9-11 7Oil jet
Front mark
6ENOO6lCONNECTING ROD
(1) The same connecting rod is used as that used in the 4663SOHC engine.
(2) The oil jet provided in the shoulder of the connecting rod is
used to lubricate the cylinder wall.
(3) The big-end bearing is the kelmet metal with metal backing.
CRANKSHAFT(1) The crankshaft is supported by the five main bearings.
(2) The oil passages drilled to the crankpins permit the flow of
lubricating oil from the main bearing to the connecting rod
bearing.(3) The crankshaft has been subjected to special surface
treatment. Therefore, do not grind it for reuse.
(4) The main bearing is an aluminum alloy with a backing of
another metal. The center bearing is provided with flanges
to receive the thrust load of the crankshaft.
Oil passage
6EN0089
16ENOOQO
Oil passage
INo. 51MAIN BEARING CAPSThe No. 1 and No. 2 main bearing caps are joined, as are the
No. 4 and No. 5 main bearing caps, by means of a beam to
minimize vibration of the bearing saddles and to enhance
rigidity of the crankshaft support.
--
.--. _A

ENGINE - Base Engine
ROCKER ARM
(1) The cam follower of the rocker arm is a roller with nea,.,-
bearings.
v
,I$- I- ‘Roller
Needle bearing6ENOlOI
6EN025-4
2-valve SOHC slipper type
9O-valve DOHC roller type1
02.5005.000Engine speed
rpm6ENOl o(Camshaft
I-Oil passage ,
EIr(2) A jet of oil spurts onto the contact area between the cam
and roller from an oil jet located on the fulcrum side of the
rocker arm.
(3) Since the roller rotates as the cam rotates, friction loss is
drastically reduced as compared with the conventional
slipper type.
(4) Due to the construction of the roller rocker arm, the valve
train driving torque is reduced to about half that of the
conventional slipper type, which is equivalent to, or
compares favorably with, the
2-valve SOHC slipper type. All
these factors contribute to enhanced engine performa
and fuel economy.
LASH ADJUSTER
,The hydraulic lash adjuster is of the end pivot type. It eliminates
the need for adjustment of the valve clearance. There are four
lash adjusters provided for each cylinder, 16 in all.
Rocker anIF=Lash adjuster
-
Cylinder head
--Valve
‘-Reservoir chamber
6E NO255
-6EN0256

5-jENGINE- Base Engine9-15Operation of the Lash Adjuster
When the valve starts opening
/f-b
During the valve opening stroke
n
6EN0254
When the valve coiqpletesthe opening stroke
6EN0257
6EN0256
(1) Before the valve starts opening:
--
No external load is applied to the
plunger, thus
causing the plunger to be pushed UP
by theplunger spring, maintaining zero clearance.
.(2) When the valve starts opening:
When the cam pushes the rocker arm, the ball inthe high-pressure chamber immediately is held
pressed against the seat by the hydraulic press-
ure. fully closing the high-pressure chamber. AS
the check ball closes, the pressure in the
high-pressure chamber surges causing the plun-ger to support the load from rocker arm, which
.allows the valve to start ooenino.
- -__
(3) During the valve opening stroke:
A very small amount of oil leaks through the
clearance between the lash adjuster body and
plunger.
(4) When the valve completes its opening stroke:
There is no external load being applied to the
plunger as the valve closes, causing the plunger
to be pushed up by the plunger spring. This
causes the pressure in the high-pressure cham-
ber to be lowered, which pushes the check ball
open. The oil which has leaked is replaced in thehigh-pressure chamber from the reservoir cham-
ber.
-

9-16ENGINE- Base Engine
Hydraulic Flow to Lash Adjusters
To lash adjuster onthe exhaust side
P
)
5-Valve body
.Lash adjuster
6EN0107
:.-.
2:.
4
‘.’Relief plunger
I?.,:.:.;
/Lash adjuster
-Cylinder head bolt hole
PlugTo
tash adjuster onthe intake side
Relief spring
-Valve body
6EN0108The oil moves through the cylinder head bolt hoie to
the oil passages drilled in the cylinder head. Andthen has its pressure regulated by the valve body k
pressure regulator) and is supplied to each
la:
adjuster.
-:

9-18ENGINE- Base Engine
(1) The intake camshaft, exhaust camshaft, and the
oil pump are driven by a single timing belt.
(2) Timing belt tension varies at different engine
temperatures and ages of the belt. The autotensioner absorbs these changes in belt
ten+n,not only to prevent the noise problem
getting worse, but to improve durability as weli’l
AUTO TENSIONER
Piston -1
Check ball-4,
SpringTensioner
cwllev
6EN0116
LOoil seal
6ENOWThe auto tensioner applies tension to the timing belt
by causing the tensioner arm to move back and
forth in the directions shown by arrow
@I.The bottom figure shows the construction of the
aUt0 tensioner. The chambers on the right and leftof the piston
are filled with silicone oil.
Both the tensioner pulley and idler pulley are of the
ball bearing type into which grease has been
packed.

,_-.._-~_._. I _ ‘... ----
ENGINE- Base Engine9-19
Reservoir
chamber/
Reservoir
chamber
PressurechamberOperation of the Auto Tensioner
WHEN THE BELT TENSION HAS INCREASED
(1) The tensioner arm pushes the piston in the direction shown
by
arrow @, causing the hydraulic pressure in the pressurechamber to build up.
(2) The check ball closes.
(3) The oil inthepressure chamber is compressed by the
piston, which causes a small amount of oil to gradually leak
through the clearance between the piston and cylinder into
the reservoir chamber. This causes the piston to move
slowly in the direction shown by arrow
@.
(4) The piston stops moving when the load in the direction @balances the spring tension, which determines the load,
i.e., tension, applied to the belt.
WHEN THE BELT TENSION HAS DECREASED
(1) The piston moves in the direction shown by arrow @I by the
spring tension.
(2) As the piston moves, the hydraulic pressure in the pressure
chamber becomes lower than that in the reservoir cham-
ber.
(3) The check ball opens.
(41 Oil enters the pressure chamber.
(5) The piston stops moving when the belt tension balances
the spring tension, which determines the tension applied to
the belt.
_ . _ ---___- -

9-20ENGINE- Lubricathn System
LUBRICATION SYSTEM
nasllOil cooler*
r-4--I-
(oil pressure regulator)
I
n I-1Oil filter
pressureswttch
NOTE
l
: Turbo6LUOO43The lubrication system is the pressure-feed, full-
flow filter system. The engine oil sent under
pressure by the gear-type oil pump is filteredthrough the cartridge-type oil filter before being
delivered to the various engine parts.
SPECIFICATIONS
ItemsOil pump
Type
Delivery rate
Relief valve opening pressure
Oil pressure switch
Type
ON pressureOil filter
Specifications
Gear type
10 cm” (.Sl cu.in.)/engine revolution
550 kPa (78 psi) or more
Contact-point type
30 kPa (4.3 psi) or less
Cartridge type

FUEL SYSTEM - General14-3The fuel is supplied under pressure by the in-tanksent to the engine control unit.
type fuel pump, and is injected from injectors into allThe crank angle sensor converts the crank
angle,
cders. The injectors are activated by signals fromthat is, engine turning state into an electric signal
tk, engine control unit, and the amount of fueland sends it to the engine control unit.
injected is determined according to the drivingThe engine control unit, based on these signals,
conditions.determines the basic activation timing of the
injec-The intake air passes through the air flow sensor,
tars. The amount of intake air is determined by the
throttle body, air intake plenum and intake manifold,degree of opening of the throttle
valye,, and during
and finally enters the combustion chamber. The airengine idling, the amount of intake
arr IS regulated
flow sensor detects the amount of air flow and
by the idle speed control servo.converts this data to electric pulse signals that are
EGR temperature sensor (California) 7
Waste gate solenoid valve
Purge control solenoid valve
EGR control solenoid valve Fuel pump relay
Control relay
Air conditioner relay
Diagnosis output
Ignition coil
Control relay (Fuel pump drive
signal)Vehicle speed
SensorIgnition switch “ST” terminal
Ignition switch
‘IG” terminal
Air conditioner switch
Power steering
switch
Inhibitor switch
Idle speed
ontrol servoFast idle
air valve
-Throttle
&r -kilo m-i&inn’Power transistorleturn to-
uel tank- Fuel from
Coolant temperature sensor
Coolant temperature switchFuel-pressure
control valve
Detonation sensor
4