stop start NISSAN 300ZX 1984 Z31 Engine Fuel And Emission Control System Workshop Manual

E. C. C. S. DESCRIPTION
E.C.C.S. Components (Cont’d)
E.G.R. CONTROL SOLENOID VALVE
E G R control solenoid valve cuts intake manifold
vacuum signal for
E G.R control The solenoid
valve actuates in response to the ON/OFF signal
from
the E C.C S control unit. When the solenoid
is off, vacuum signal from intake manifold is fed
into the
E G R control valve As the control
unit outputs an ON signal, the coil pulls the
plunger downward, and cuts the vacuum signal
9 Atmosphere
ToEGR control valve
From intake
SEF6336 0 manifold
FUEL PUMP
The fuel pump, which is located in the fuel tank, IS
a wet type pump where the vane rollers are directly
coupled to
a motor which is filled with fuel
1 Outlet A
AIR REGULATOR
Air regulator gives an air by-pass when the engine is
cold for the purpose of a fast idle during warm-up
SE F635 B
A bimetal, heater and rotary shutter are built into
the air regulator When the bimetal temperature
IS
low,
the air by-pass port is open As the engine
starts and electric current flows through a heater,
the bimetal begins to rotate the shutter
to close off
the by-pass port The air passage remalns closed
until the engine
is stopped and the bimetal tem-
perature drops
SEF636B
EF & EC-19

E.C.C.S. DESCRIPTION
FUELPUMP ~
FUEL PUMP RELAY
Fuel Pump Control
108
ECCS
CONTROL UNIT
Engine speed --r
Engine temperature
control Fuel pump Start signal
Ignition
switch
position Engine
condition
Throttle valve idle position
Fuel pump Fuel pump
relay operation
Battery voltage Battery
Starting ON
ON for 30 Operates
seconds
Fuel pump voltage control
The fuel pump is controlled by the E C C S con-
trol unit adjusting the voltage supplied to the fuel
pump
Conditions
5 seconds after ignition switch is
turned to ON
Engine cranking
25 5 seconds after engine stan
[above 50°C (122°F)1
Engine temp above 90°C (194OF)
Engine temp below 10°C (50°F)
Except above
Voltage
Approximately
134 [VI
94-134 [Vl'l,
10 1 - 13 4 [VI '2
'1 VG30E engine
"2 VG30ET engine
I SEF643B
Operates for
I OFF I 5 seconds Stopped
I Running I OFF I Operates
Stops in 1
I I I second After stall OFF
EF %t EC-217

DIAGNOSTIC PROCEDURE
Driveabil
1. Inspect engine and E C C.S. for air leaks,
proper electrical connections, etc
1) Check all hoses and ducts for air leaks
2) Check air cleaner for clogging
3) Check harness connectors for proper connec-
tions
4) Check ignition wiring
5) Check gaskets for leaks at all air intake com-
ponents
6) Check E G.R valve operation
7) Check air regulator operation
2 Perform E C C S self-diagnosis
Follow the procedure in E CCS SELF-
DIAGNOSIS (Page EF & EC-35)
3 Check idle speed and ignition timing
a. Prepare the following conditions:
Headlampswitch' OFF
Heater blower: OFF
Air conditioner switch: OFF
Front wheel (Power steering model):
KEEP STRAIGHT AHEAD
b. Warm engine to operating temperature.
Check
and adjust as follows
[VG30E engine (Without turbocharger)]
1) Stop engine and disconnect idle-up solenoid
valve harness connector
Idle-up solenoid
2) Start engine and race engine two or three times
under no-load, then run engine
at idle speed
(Cont'd)
3) Check idle speed
M/T & A/T (in "D" position)
700250 rpm at sea level
650250 rpm at high altitude condition
If necessary, adjust to the specified
speed by
turning idle speed adjusting screw
I, SEF6456
4) Stop engine and connect idle-up solenoid valve
harness connector
5) Start engine and check ignition timing with
a
timing light
20ai2" B.T.D.C.
If necessary, adjust ignition
timing by turning
distributor
[VG30ET engine (With turbocharger)]
1) Race engine two or three times under no-load,
then run engine at idle speed
2) Check idle speed.
M/T: 70W50rpm
A/T: 650k50 rpm (in "D" position)
EF & EC-30

DIAGNOSTIC PROCEDURE
Driveabili
If out of specification, adjust as follows
ness connector
a Stop engine and disconnect A A C valve har-
SEF646B
b Start engine and adjust engine speed by turning
idle speed adjusting screw
M/T: 650 rpm
A/T. 600 rpm (in "D" position)
c. Stop engine and connect A.A.C. valve har-
ness connector Then
start engine
d Make sure that idle speed
is in the specified
range.
3) Check ignition timing with a timing light
ZO"r2" B.T.D.C.
If necessary, adjust ignition timing by turning
distributor
Perform mixture ratio feedback
system inspec-
tion Follow the procedure
in MIXTURE RATIO
4
(Cont'd)
FEEDBACK SYSTEM INSPECTION (Page EF
lk EC-60)
5 Perform driveability test
Evaluate effectiveness of adjustments by driv-
ing vehicle If unsatisfactory, proceed to step
6
6
Perform electronic control system inspection
Check the following using circuit tester
Injector circuits
Air regulator circuit
E G R control solenoid circuit
E xhaust gas sensor heater circuit
Follow the procedure in ELECTRONIC CON-
TROL SYSTEM INSPECTION (Page EF
& EC-
43)
7 Check idle mixture ratio
1) Warm up engine to operating temperature
2) Turn off engine and disconnect throttle valve
switch harness connector
3) Verify that the diagnosis mode selector is
turned fully counterclockwise
4) Start engine and verify that engine IS still at
operating temperature.
5) Race engine two or three times under no-load,
then run engine
at idle speed
6) Look at inspection lamps (red and green)
SEF648B
When both inspection lamps blink, it indicates
that the idle mixture ratio IS correct.
EF & EC-31

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

FUEL SYSTEM INSPECTION
Fuel Pressure Check (Cont'd)
6 Stop engine and disconnect fuel pressure re-
gulator vacuum hose from intake collector
7
Plug intake collector with a rubber cap
8 Connect variable vacuum source (J-23738 or
equivalent) to fuel pressure regulator.
9 Disconnect fuel pump connector and apply
battery voltage
as follows
SEF717B
10 Start engine and read the indication of fuel
pressure gauge as vacuum is changed
Vacuum Fuel prerrure
SEF718B
Vacuum Fuel pressure
kPa (mmHg, inHg) kPa (kg/cm2, psi1
0 (0.01 248 1 .255 0
(2 53
- 2 60.36 0.37 01
227 5.241 3
(2 32.2 46,330.35
01 16 9 (127, 5 00)
213 8.220 7
(2 18.2 25,31 0 - 32 01 33 9 (254. 10 001
200 1 - 206 9
(2 04
- 2 11.29 0- 30 01 50 8 (381,15 00)
179 5. 193 2
(1 83-197.260-280) 67 7 (508.20 00)
Fuel pressure should decrease as vacuum increases.
If results are unsatisfactory, replace fuel pressure
regulator.
EF 8t EC-64