Datsun 1980 200SX Service Manual page 29

Minor Trouble
Diagnoseund
Corrections
MAINTENANCE
Condition
Connecting
rod
bearing knocking
Piston and
cylinder
noise
Piston
pin
noise
Water pump noise
Others
Others
ABNORMAL
COMBUSTION
backfire
after fire
run on
etc
Ignition
system
in trouble
Fuel system
malfunction
MA 20
Probable
cause
This
is
a
little higher pitched
noise than the
crankshaft
knocking
and also increases
when
engine is
accelerated
Cause
a
misfue
on
each
cylinder and if the
noise
diminishes
almost
completely
this crankshaft
bearing
generates
the
noise
When
you
hear
an
overlapping
metallic
noise
which increases its
magnitude
with the
revolution of engine and which decreases
engine
is wanned
up
this
noise is
caused by
piston lUId
cylinger
To locate the
place
cause a
misfue
on
each
cylinder
This
noise is
heard
at
each
highest
and
lowest dead end of
piston
To locate the
place
cause a
misfire
on
each cylinder
This
noise
may
be caused by
worn or
damaged
bearings
or
by
the
uneven
surface
of
sliding parts
An
improper
adjustment
of valve clearance
Noiseoftinringchmn
An excessive end
play
on
crankshaft
Wear
on
clutch
pilot bushing
This
noise will be heard when clutch
is
disengaged
Improper ignition tinring
Improper
heat range of
spark plugs
Intake air
leakage at following points
Dipstick
Oil f1l1er
cap
Bl o w by hoses
Intake air duct air flow
meter to
throttle
chamber
etc
Damaged electronic fuel injection harness
Damaged
control
unit
Malfunctioning air flow
meter
Damaged
water temp
sensor
Corrective
action
Same
as
the
case
of crankshaft
bearings
This
may cause an
abnonnal
wearing
of
cylinder
and lower compression which in
turn
will
cause a
lower
out
put
power
and
excessive
consumption
ofoil
Overhaul
engine
This
may cause a wear on piston pin
or
piston pin hole
Renew
piston
and
piston pin
assembly
Replace water
pump with
a new one
Adjust
Adjust
the
tension
of chmn
Disassemble
engine and
renew
main
bearing
Renew
bushing
and
adjust
drive shaft
Adjust ignition timing
Use
specified spark plugs
Repair
or
replace
Replace
Replace
Replace
Replace
J
For inspection
procedures
for
electronic
fuel
injection
sys
tern
components
refer
to
Engine
Fuel Section