Mitsubishi 3000GT 1991, Service Manual

Page: 66 / 1146

ENGINE
Service Adjustment Procedures
MANIFOLD VACUUM INSPECTION
The vehicle should be repaired as follows before the
inspection.
l
Engine coolant temperature: 80 95°C (176 205°F)
l
Lights, electric cooling fan, and accessories: OFF
l
Transaxle: Neutral for
l
Steering wheel: neutral position
Connect a tachometer. (Refer to P.l l-l 3.)
(3) Disconnect the vacuum hose from the nipple for taking off
fuel pressure regulator vacuum from the air intake plenum.
Conncet a three-way joint between the removed vacuum
hose and the nipple and connect a vacuum gauge to the
joint.
(5) Start the engine and check that idle speed is within the
standard value range.
Check the manifold vacuum.
Standard value:
<Non-Turbo>
<Turbo> Approx. 520 (20
Approx. 495 (19
LASH ADJUSTERS CHECK
Ml 1 FEAF
If an abnormal noise is heard from the lash adjusters, check as
follows.
(1) After warming up the engine, stop it.
(2) While installed to the cylinder head, press the part where
the rocker arm contacts the lash adjuster at the very top. If
the adjuster is normal, the part pressed will feel very hard.
If it easily moves all the way downward when pressed,
there is a malfunction of the lash adjuster and it should be
replaced with a new one.
If it feels spongy or elastic, probably oil with air mixed in it
has entered the lash adjuster. Check whether the amount
of oil is too much or is not enough and the cause of air
becoming mixed into the oil is a damaged oil screen or oil
screen gasket.
After repairing the cause of the air leak, warm up the engine
and then drive the vehicle at low speed for a while. Stop the
engine and leave it off for a few minutes; then restart the
engine and drive at low speed. Repeat this procedure
several times during the course of about one hour so as to
remove the air from the oil.
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