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

MIXTURE RATIO FEEDBACK SYSTEM INSPECTION
Repair or replace E C C S harness
SEF71OB
SEF7118
f
Connect a resistor (2.5 kS2) between terminals of cylinder
head temperature sensor harness connector
I
Start engine and warm up engine until water temperature
indicator points to the middle
of gauge
Race engine two or three times under no-load. then run
engine
at idle speed
After checking CO%,
1) Disconnect the resistor from terminals of cylinder head
temperature sensor
2) Connect cylinder head temperature sensor harness
connector to cylinder head temperature sensor
ness, and disconnect throttle inspection lamp on control unit goes on and off more
I
Turn off engine and remove air flow meter from
vehicle ~~
Drill a hole
in seal plug which seals variable resistor of
air flow meter and remove seal plug
warm up engine until water temperature indicator
Varrable resistor scmw
SEF7128

MIXTURE RATIO FEEDBACK SYSTEM INSPECTION
SEF7138
SEF649B
Install air flow meter on vehicle
P
of air flow meter so that inspection lamps blink
Not adjustable Adjustable
Replace air flow meter
Turn off engine and remove air flow meter from vehicle
1
Insert new seal plug into variable resistor hole Tap seal
plug with a suitable bar, thereby installing seal plug on air
flow meter
1 Connect throttle valve switch harness connector I---
EF & EC-62

FUEL SYSTEM INSPECTION
Releasing Fuel Pressure
Before disconnecting fuel line, release fuel pressure
from fuel line to eliminate danger.
1 Start engine
2. Remove luggage floor mat
3 Disconnect fuel pump connector with engine
running
SEF7148
4 After engine stalls, crank engine two or three
times to make sure that pressure
IS released
5. Turn ignition switch off and connect fuel
pump connector.
--Fuel Pressure Check
a. When reconnecting fuel line, always use new
clamps and be sure to position them correctly.
b. Use a torque driver to tighten clamps.
c.
Use Pressure Gauge (5-2540034) to check fuel
pressure.
I Fuel tank I -A
SEF7158
1. Release fuel pressure to zero
2 Disconnect fuel hose between fuel filter and
Fuel tube (engine side1
3. Install pressure gauge between fuel filter and
Fuel tube
SEF7168
4
5
Start engine and check for fuel leakage.
Read the indication of fuel pressure gauge
At idling:
Approximately 206 kPa
(2.1 kg/cm2, 30 psi)
The moment accelerator pedal is fully
depressed
:
Approximately 255 kPa
(2.6 kg/cm2, 37 psi)
EF & EC-63

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

FUEL SYSTEM INSPECTION
Injector Removi
1
2
Air duct E G R tube
Accelerator wire Harness clamps
Blow-by hoses Harness connectors
Air regulator hose Intakecollector cover
3 Disconnect fuel hoses
Release fuel pressure to zero
Disconnect the following from intake collector.
4 Remove intake collector
5 Remove bolts securing fuel tube
6. Remove bolts securing injectors and remove
injecton, fuel tubes and pressure regulator
as
an assembly
and installation
7 Remove fuel hose
1) Heat soldering iron (150 watt) for 15minutes
Cut hose into braided reinforcement from
mark to socket end and
fuel tube end.
Do not feed soldermg iron until it touches injector
tail piece.
Socket
Fuel tube
Injector holder Soldering iron
InjeCtor rubber
Snap rtng
injector hosef O-ring
SEF719B
2) Then pull rubber hose out with hand.
a.
Be careful not to damage socket plastic con-
nector, etc. with soldering
iron.
b. Never place injector in a VIS when dixon-
necting rubber hose.
8
Install fuel hose as follows.
1) Clean exterior of injector
tail piece and fuel
tube end.
2) Wet inside of new rubber hose with fuel
3) Push end of rubber hose with hose sockets
onto injector tail piece and fuel tube end by
hand
as far as they will go
Clamp is not necessary at the connections.
CAUTION:
After properly connecting fuel hose
to injector and
fuel tube, check connection
for fuel leakage.
EF & EC-65

TURBOCHARGER
Disconnected or cracked rubber hose
I ~~ ~
~ Condition 1 Low engine power
Probable cause Corrective action I
Correct or replace rubber hose
Air leak at the connection of compressor housing and
suction hoselinlet tube, or inlet tube and intake manifold Correct the connection
Correct the connection or replace gasket Exhaust gas leak at the connection of turbine housing
and exhaust manifold. connectina tube or exhaust outlet
I - I I I
Stuck or worn journal or bearing
Replace turbocharger assembly
Broken turbine wheel I--+
I Condition 2 Excessively high engine power 1
EF & EC-66

TURBOCHARGER
Worn journal or bearing
Inspection (Cont’d)
Replace turbocharger assembly
I Condition 3 Excessively high oil consumption or exhaust shows pale blue smoke I
Probable cause Corrective action
Oil leak at the connection of lubricating oil passage Correct the connection
1. Inspect turbine and compressor wheel as
follows
Visually check for cracks, clogging, deformity
or other damage
Revolve wheels to make sure that they turn
freely without any abnormal noise or friction
Measure play in axial direction
Play (axial direction):
0.013.0.091 mm (0.0005 - 0.0036 in)
SEF726B
2 Check operation of by-pass valve controller
Move by-pass valve to make sure that
it is not
sticking or scratched.
Measure rod end play of the bypass valve con-
troller
Do not apply more than 66.7 kPa (500 mmHg,
19.69 mHg) pressure to controller diaphragm
0.38 mm (0.0150 in)/51.3 - 56.7 kPa
(385 - 425 mmHg, 15.16 - 16.73 inHg)
By-pass valve controller strokelpressure.
,vMercury manometer
,-By-parr valve controller
SEC7278
Always replace the turbocharger as an assembly if
faultv
EF & EC-67

TURBOCHARGER
Removal and Installation
Turbocharger should not be disassembled
&- Exhaw manifold
(c1 18 -22 (1 8-22.13-161
10 -22 I1 0 -22.7.161
011 delivery tube
From cylinder block
*@
15-2OI15-20.11 14)
Turbocharger assembly
p? N m lkg-m. ft-lbl SEF724B
Remove the following
Compressor and compressor bracket
Exhaust front tube
Center cable
Heat insulator for brake master cylini
Air duct and hoses
Exhaust manifold connecting tube and heat
shield plate
Oil delivery tube and return hose
Remove exhaust manlfold and turbocharger
as
an assembly
SEF725B
3
4
Disconnect the turbocharger from the exhaust
manifold
When installing turbocharger
to exhaust mani-
fold, securely tighten nuts and bend
up new
lock washers
EF 8i EC-68

INJECTOR COOLING FAN (VG30ET)
-2
INJECTOR
COOLING
FAN MOTOR
The injector cooling fan operates to cool down the
temperature of fuel inside the injector and the fuel
gallery when engine is stopped under high engine
temperature condition
Operation 1
I
-1
lgnltl.3" ON
OFF switch
FANMOTOR TIMER UNIT
- - 3 6
Water I ON temperature witch
motor Fa" OFF 'PI OFF
Fa" motor OFF I
I About 17 monutes
SEF7296
OFF
Operation 2
ON Ignition switch OFF
ON
I iI
Water temperature witch OFF ~
Abut 17 minuter
SEF730B
Operation 3
ON I ON , Ignition twitch OFF
SEF7326
EF & EC-69

INJECTOR COOLING FAN (VG30ET)
Inspection
START
T
Disconnect water temperature switch harness connector
and connect the terminal to ground with
a jumper wire
I
Turn ignition switch
I OFF+ON+OFF L
1
I
Make sure that cooling fan motor starts to operate 1 NG I IOK I
1
Check harness for continuity ~~
[ Perform
component check
COMPONENT CHECK
A Fan motor
1 Make sure that continuity exists between
terminals of fan motor
SEF734B
2. Apply battery voltage to the terminals of fan
motor. If fan motor
does not operate, replace
SEF7358
EF & EC-70