Service Repair Manual

MPI SYSTEM
Check points
Check conditions
Test
specification
Probable cause of malfunction
EGR temperature o Engine: warm
Engine
Temperature o Check the EGR temperature
sensor
condition
°C (°F) sensor.
[California vehicle
o Check the EGR control system.
only)
700 rpm
70 (158)
(Idle)
or less
o Check the EGR valve.
o Service data
o Check the EGR control solenoid
o Item No.43
3,500 rpm
70 (158)
valve.
o Disconnect
or more o Check the EGR control vacuum.
the vacuum
hose (yellow)
stripe from the
A port nipple
of the throttle
body, and
pinch the hose
end with your
fingers.
Injectors
o Actuator test
o Item No.1-4
Injector
o Service data
o Item No.41
o Engine: idle
Injector No.
Engine
o If the idling
condition doesn’t
after warm-up
1
(Cut off the
Unstable idle
change, check the cylinder.
1) Check the injector operation
injectors in
2
sound.
sequence dur-
2) Check the spark plug and
ing idle after
3
high-tension cable.
engine warm-
4
3) Check the power transistor unit
up; check the
and control circuit.
idle condition.)
4) Check injecting condition
o Engine: warmed Engine
Activation o If the injector activation time is
up
condition
time (msec.) unusually long or short, there is a
700 rpm
2.2-2.9
malfunction of the air-flow sensor,
(Idle)
engine coolant temperature sensor,
intake-air temperature sensor, or
2,000 rpm
1.8-2.6 barometric pressure sensor.
Rapid racing
Increases
o If the injector activation time is
long, increased engine resistance or
leakage of compression pressure is
probable.
Ignition advance
o Engine: warmed Engine speed
(power transistor) up
(rpm)
o Service data
o Timing light: set
o Item No.44
700 (Idle)
2,000
Ignition
advance
(°BTDC)
8-12
26-34
o If the ignition advance and actual
ignition timing are different, adjust
the ignition timing.
[The ignition timing may fluctuate
during idling, but this is not a
problem. The advance is greater
(approx. 5°) at high altitude.]
31-42