NISSAN 300ZX 1984 Z31 Engine Fuel And Emission Control System Repair Manual

ELECTRONIC CONTROL SYSTEM INSPECTION
Start engine, turn air conditioner switch "ON" and
check compressor operation
@! NeutraVPark switch (Code No. 24)
N G + Check air conditioner system
Check harness for continuity F.1 Repair harness
OK I
NG -
Check neutrallpark swltch
Repair harness
Press I)
Free INeutrall 057 press IOtherrl -57 SEC764
OK I
Replace neutrallpark switch
I"
Replace E C C S control unit
0 Air condttloner (Code No. 31)
Stop engine and disconnect 16-pin connector Turn
ignition switch
"ON" and measure voltage between
terminal
@ and ground
I Battery voltage
SEF690B
OK I
+
Replace E C C S control unit
EF & EC-51

ELECTRONIC CONTROL SYSTEM INSPECTION
@ Start signal (Code No. 32)
Repair or replace NG Check starting system 1
OK
20-pin connector and measure voltage between
terminal and ground
Emery voltage
SE F691 B I OK I
Replace E C C S control unit
@ Detonation sensor (Code No. 34)
1 ) Disconnect detonation sensor harness connector
2)
Start engine and increase engine speed while
checking ignition timing
3) Check if ignition timing retards by 5 degrees when
engine speed increases when engine speed increases
more than 2,000 rpm
I SEF692B
Repair harness
(Refer to
EL section I
Replace E C.C.S control unit
Repair harness N.G OK1
Replace detonation sensor.
EF & EC-52

ELECTRONIC CONTROL SYSTEM INSPECTION
Replace E C C S control unit
Fuel temperature sensor (Code No. 41)
Replace fuel temperature sensor and
Disconnect 20-pin connector and measure the
resistance between terminal
@ and ground
Fuel temperature I Resirlance
Above20'C 168'Fl I Below 2 9 kC
Below 2O:C 168"FI Above 2 1 kC1
-
SEF693B
Repair harness 1
Measure the resistance of the fuel temperature sensol
i c3425 2
1 '"
-
- :2
2 - ? 103
i6
-24 Y
t+2
10'
-30 0 40 80 1M (-221 (321 (1041 (1761 (248) -20 20 60 100 130 1-41 (681 (1401 12121 (2661
Temperarure 'c 1°F) -
EF %I EC-53

ELECTRONIC CONTROL SYSTEM INSPECTION
Check harness ~~
@ Auxiliary
air control (A A.C.) valve or idleup solenoid valve
Repair harness
Disconnect E C C S 20-pin connector, and check
voltage between terminal @and ground when igni-
tion switch
is turned to ON
LEU Battery voltage
I SEF695B
NG I
Replace E F I relay the fuel pump relay. check E F I relay I
OK I
Check A A C valve or idle-up solenoid valve
Replace A A C valve or idle-up
solenoid valve
I
EF & EC-54

ELECTRONIC CONTROL SYSTEM INSPECTION
NG Check harness for continuity c
@ E.G.R. control valve
Disconnect E C C S 20-pin connector, and check
voltage between terminal @and ground when igni-
tion switch
is turned to ON
Repair harness
Battery voltage
SEF697B
NG
Using the same procedure as that for
the fuel pump relay, check
E F I relay
NG Replace E F I relay
Check E G R control valve for continuity
m
SEF6988
Check E G R control valve for operation
Armorohere
0 From intake
R ".I". d ToEGR Control Valve
When applying 12 "Oltl manifold SEF79ZB
NG - Replace E G R control valve
EF & EC-55

ELECTRONIC CONTROL SYSTEM INSPECTION
@ Air regulator
Disconnect E C C S 20-pin connector, and check
voltage between terminal @and ground when igni-
tion switch
is turned to ON
I I
Battery "Dltage
SEF699E
NG I
Check harness . Repair harness
Check air regulator
a Check continuity
I
Continuiry should enst SEF700B
b Remove air regulator and visually check shutter
opening.
0 When engine is cold Open
0 After warm-up Closed
c Pry air regulator shutter to open with a screw-
driver, and check
if shutter opens and closes
smoothly
I
Replace air regulator
EF & EC-56

ELECTRONIC CONTROL SYSTEM INSPECTION
OK -
@ Exhaust gas sensor heater
Disconnect E C C S 15-pm connector, and check
voltage between terminal@ and ground when igni
tion switch
IS turned to ON
Check harness
I J
Battery dtqe
SEF701
NG
+
Measure the resistance of exhaust gas sensor heater
Renslance 2 87kO Pa
SEF702E
NG I
Replace exhaust gas sensor
EF & EC-57

ELECTRONIC CONTROL SYSTEM INSPECTION
@ Injector
Disconnect E C C S 15pln connector, and check
voltage between terminal@,@,@,@,@,
@and ground
n
Battery voltage
SEF703B
NG I
Check each injector for continuity
SEF7MB COnttnuny should exin
4
Replace injector
END OK
Check harness
EF & EC-58

ELECTRONIC CONTROL SYSTEM INSPECTION
@ Battery source and ground
Dlsconnect E C C S 16-pin connector, and check
voltage between
a, @and @,@ when lgnltlon
switch
IS turned to ON
J .
J
Battery voltage SEF705B I
NG
Repair harness
EF & EC-59

MIXTURE RATIO FEEDBACK SYSTEM INSPECTION
SEF707B
START
-
Make sure that the following are normal
engine at idle speed
SEF651B
SEF70BB
een
jumper wire.
connector and ground metal
on vehicle body
Continuity exists
. . .. .. . . 0 K.
Continuity does not exist . . .. N G
4) Check for continuity between terminal @ of 16-pin
SEF706B
t
Verify that diagnosis mode selector is turned fully
cou nterclockwise
1
Run engine at about 2,000 rpm for about 2 minutes under
no-load
I
4
Make sure that inspection lamp (Green) on control unit
aoes
on and off more than 5 times durinq 10 seconds
I i2~000 rom) .. .~,. ~ ~
OK
Disconnect throttle valve switch harness connector
1
I Race engine two or three times under no-load, then run I
I JG
1
SEF709B
EF 81 EC-60