Datsun 1980 200SX Service Manual page 127

Trouble
Oisgnosesand
Corrections
ENGINE FUEL
Condition
Engine
will
not
re
volve lack of
power
Hesitation stumble
on
acceleration
EF 40
Probable
cause
Malfunctioning control
unit
Improper
fuel
pressure
improper
EFI circuit
Lor
t
f
ignition
system
Malfunctioning
throttle valve
Malfunctioning air
flow
meter
Improper
fuel line
Improper
fuel
pressure
Problem in the
followiIlg
circuits
Ignition coil trigger input
circuit
Control unit
power
input
circuit
Injector
circuit
Air flow
meter potentiometer
Throttle valve switch idle
contact
and
full throttle
contact
Vacuum switch
Air
temperature sensor
Water
temperature
sensor
Altitude
sensor
Air
re
ator
and fuel
pump circuit
Improper ignition
system
Malfunctioning
air flow
meter
Intake
air
leakage
at following points
P C
V
valve
V C valve
Dipstick
and oil filler cap seals
Manifold gaskets
Air flow
meter
hoses
etc
Improper
fuel pressure
Improper
idle CO ll
adjustment
Improper
EFI circuit
Check and
corrective action
Tap control unit while
driving
to
see
if this
aggravates or
aIleviates the
problem
If
so
try
another control
unit
Perfonn fuel
pressure test
Perfonn all circuit
tests
Then
perfonn Component checks
Check IC
ignition
unit
pick
up
coil and
igni
tion
coil
Make
sure
throttle plate
is
opening
fully
when accelerator is
fuI1ydepressed
Check
air flow
meter
mechanical
movement
Using
a
finger push
flap
open
checking
that
it
opens
smoothly
and
fully
Check fuel line for blockage
Tank strainer
Fuel fdter
Fuel
pipes
Perfonn fuel
pressure test
Check each circuit
Thin
perfonn
Component
checks
Check ignition
system
Check air
flow
meter
mechanical
movement
Using
a
finger
check for smooth
flap
move
ment
Check for intake
air
leaks
Perfonn fuel
pressure test
Check idle
CO ll if necessary
adjust it
Perfonn
complete
circuit test
Then
perfonn Components
checks