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

E.C.C.S. DESCRIPTION
E.C.C.S. Components (Cont'd)
A
Air flow meter 0.
C
AIR FLOW METER
The air flow meter measures the mass flowrate of
intake air. Measurements are made in such
a man-
ner
that the control circuit emits an electrical out-
put signal
in relation to the amount of heat dissi-
pated from the hot wire placed
in the stream of
intake
air.
E F I relay
Battery source
Output voltage
Variable resistor
25 unit Ground
Self-cleaning ignition switch
Ground
El -
-
6- 31 27 35 1
w30 ECCS 6 comroi
F- 12 34 -
-
I SEF615B
SEFSlSB
The air flowing around the hot wire removes the
heat from
the hot wire The temperature of the hot
wire
is very sensitive to the mass flowrate of the
air.
The higher the temperature of the hot wire, the
higher
its resistance value This change in the
temperature (or. resistance)
IS determined by the
mass flowrate of the air. The control circuit
ac-
curately regulates current (I) in relation to the
varying resistance value
(RH) so that VA always
equals VB The air flow meter transmits an output
for voltage
VA to the control unit where the
output
is convened into an intake air signal.
I
Temperature compensation resistor
twire
Hot wore reststance
Temperature campenration resistance RA. RB Constant reSiiIanCe
RH RK
SEFS17B
I
EF & EC-14

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

ELECTRONIC CONTROL SYSTEM INSPECTION
OK -+
@ Fuel pump (Code No. 22)
Replace E C C S control unit
Turn ignition switch "ON" and listen to the fuel
pump operating sound The sound must be heard for
about
5 seconds
Check Normal
12V direct current
18 applied between ~
Disconnect E C C S 15-pin
connector. and check
voltage between terminal
@ and ground when
ignition switch
is turned to ON
Replace fuel pump
Battery voltage
SEF683B
OK I
Replace fuel pump relay
Check fuel pump for ContinuitY
Contmuny should exis
SEF684B
OK1 ING
Check harness for continuity
OK I ING
I Repair harness
OK
Check fuel pump relay
NO @ - @ I C0"tl""ltY
SEF685B
ING
EF & EC-49

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