Mazda 121 - Compression

COMPRESSION
COMPRESSION
ll
rhe enoine
exnibits
low
power. poor luel economy
or
poor
ldle check
the
lollowing:
1.
lgnrtro;
system
(Beler to Sectron
G.)
2. Compressron
3. Fuel
svstem
(Fefer
to Section
F.)
INSPECTION
1 . Verifv
that the battery
is tully charged
Recharge
it if
neces-
sarv.
(Refer
to
Section
G.)
2. Warm
up the engine
to normal
operating
lemperature'
3. Turn the
engine
OFF.
4. Bemove all
spark
plugs.
5.
Disconnect
the
ignition coil
connector'
6. Connect
acompression
gaugetothe No
l spark
plug hole
7.
Fr.rlly depress
lhe acceleiator
pedal
and
crank the
engine'
8.
Record the
maxrmum
gauge
reaolng
9. Check
each
cylinder.
Compression
kPa
(kg/cm', psilrpm
B3
Siandard
1412
1t4.4,
2O4!3OO
1030
00.5,
149)-300
't96
(2.O,
26)
10.
lf the compression
in one or
more cyllnders
s rcw'
pour
a
small
amount
of engine
oil
into the
cylinder
and
recheck
the
compressrcn.
(1)
lt the compression
increases,
the
piston,
piston
rings'
or cvlinder
wall
mav be
worn
(2)
lf the compression
stays
low, the
valve
may be
stuck
or
seating
imProperly.
{3)
lt
the
comoression
in adjacent
cylinders
stays
low,
the
'
'
cvlinder
head
gaskel
may be
delective
or
the cylinder
head distorted.
11 . Connect
the
ignition
coil connector.
12. Apply antiseize
compound
or molybdenum-based
lubricant
to
the spark
Plug
threads.
13. Insiallthe
spark
Plugs.
Tidhlenino toroue:
is-zsi{.m
(i.5-2.3
m'ks'
11-17
finb)
B-10