Compression Check (B And 3B) - Toyota 3b Repair Manual

ENGINE MECHANICAL
-
Compression
Check
[B and
38] EM-27
I
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maxi-
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the
ust
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COMPRESSION CHECK [B and
38]
HINT:
lf
there
is lack of power, excessive oil consumption
or poor fuel economy, measure the
cylinder compression
pressure.
WARM
UP
AND
STOP ENGINE
REMOVE GLOW PLUGS (See pase EM-31)
NOTICE:
Make sure the load wire is not grounded.
CHECK CYLINDER COMPRESSION PRESSURE
(a)
lnstall
SST
(gauge adapter) to the glow plug
hole.
ssr
09992
-mo24
(b)
Connect SST (compression gauge)
to
SST (gauge
adapter).
ssr
09992-@024
(c)
Fully open the throttle
valve.
(d)
While cranking the engine with the starter,
measure
the compression pressure.
HINT:
Always use
a
fully
charged battery to obtain engine
revolutions of more than
25O
rpm.
(e)
Repeat
steps (a)through
(d)for
each cylinder.
Compression pressure:
3O.O
kg,/cm2
(427
pst' 2'942
kPa)
or more
Minimum pressure:
2O.Okg/cm2 (284 psi, 1,961
kPa)
Difference between each cylinder:
2.Okg/cm2 (28 psi, 196 kPa)or
less
(f)
lf the cylinder compression in one or more cylinders
is
low, pour
a
small amount
of
engine
oil
into
the
cylinder through the glow plug hole and repeat
steps
(a)through (d)for the cylinder with
low compression.
o lf
adding
oil
helps the
compression, chances
are
that the piston rings andlor cylinder bore are worn
or damaged.
o
lf
pressure stays
low, a valve may be sticking
or
seating improperly, or there may be
leakage
past
the gasket.
4.
INSTALL GLOW PLUGS (See page EM-50)
1.
2.
3.
)y
the
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