1998 NISSAN PICK-UP Repair Manual

Wiring Diagram
HEC583
FUEL CUT SYSTEMTD
EC-225

Description
This system prevents fuel filter from clogging with fuel wax.
Fuel heater system operates when fuel temperature switch and
oil pressure switch are on.
Fuel temperature switch turns on when fuel temperature
decreases below þ15ÉC (5ÉF). It remains on until fuel tempera-
ture increases to around 0ÉC (32ÉF).
If fuel temperature does not decrease below þ15ÉC (5ÉF), fuel
temperature switch will not turn on even though fuel temperature
is below 0ÉC (32ÉF).
DEC035
SEF541D
SEF411FA
FUEL HEATER SYSTEMTD
EC-226

Wiring Diagram
HEC584
FUEL HEATER SYSTEMTD
EC-227

System Inspection
1. Turn ignition switch ``OFF''. Disconnect fuel temperature
switch harness connector.
2. Connect a lead wire, as shown, between terminals of fuel
temperature switch.
3. Run engine at about 1,000 rpm. After several minutes, make
sure that fuel heater is hot.
Be careful not to burn yourself.
4. If fuel heater does not operate, check fuel heater system for
wire harness and electrical components.
Component Inspection
Fuel heater
1. Check continuity for fuel heater.
2. If fuel heater has malfunction, replace fuel filter heater.
Fuel temperature switch
Remove fuel temperature switch and check the operation by
changing atmospheric temperature using dry ice.
Temperature
ÉC (ÉF)Operation Continuity
Decreased to minus
11-19(52-66)OFF®ON ON: Exists.
Increased to approx.
0 (32)ON®OFF OFF: Does not exist.
If NG, replace fuel temperature switch.
DEC036
DEC037
DEC038
SEF909V
FUEL HEATER SYSTEMTD
EC-228

When installing, use a new O-ring.
WARNING:
Do not touch the cooled fuel temperature switch with your
bare hand.
Oil pressure switch
1. Run engine at about 1,000 rpm.
2. Check continuity for oil pressure switch.
3. If oil pressure switch has malfunction, replace it.
Fuel heater relay
1. Check fuel heater relay operation.
2. If fuel heater relay does not operate, replace it.
SEF414F
SEF415F
DEC039
.)
.DEC039
FUEL HEATER SYSTEMTD
Component Inspection (Cont'd)
EC-229

Wiring Diagram
HEC586
.
EC±FICD±01
FAST IDLE CONTROL CIRCUITTD
EC-230

Electrical Components Inspection
IACV-FICD solenoid valve
1. Disconnect IACV-FICD solenoid valve harness connectors
and vacuum hoses.
2. Connect solenoid valve connector to battery and adequate
vacuum hoses to the solenoid valve as shown in the figure.
3. Blow air into hoses.
If air flows: OK
If air does not flow: NG
If NG, replace IACV-FICD solenoid valve.
AIR CONDITIONER RELATED COMPONENTS
Refer to ``Electrical Components Inspection'', ``TROUBLE DIAG-
NOSES'' in HA section.
SEF908V
SEF011UB
FAST IDLE CONTROL CIRCUITTD
EC-231

General Specifications
PRESSURE REGULATOR
Fuel pressure
kPa (bar, kg/cm2, psi)
At idleApproximately
235 (2.35, 2.4, 34)
A few seconds after ignition
switch is turned OFF to ONApproximately
294 (2.94, 3.0, 43)
Inspection and Adjustment
Idle speed*1 rpm Base idle speed*3 750 25
No-load*2
(in ``N'' position)Target idle speed 800 50
Air conditioner: ON
(in ``N'' position)900 or more
Ignition timing 10É 2É BTDC
Throttle position touch
speed rpm1,000 150
*1: Feedback controlled and needs no adjustments
*2: Under the following conditions:
lAir conditioner switch: OFFlSteering wheel: Kept in straight-ahead positionlElectrical load: OFF (Lights, heater fan & rear window defog-
ger)
*3: Throttle position sensor connector is disconnected.
IGNITION COIL
Primary voltage V Battery voltage (11 - 14)
Primary resistance
[at 25ÉC (77ÉF)]WLess than 1.0
Secondary resistance
[at 25ÉC (77ÉF)] kW7-13
MASS AIR FLOW SENSOR
Supply voltage V Battery voltage (11 - 14)
Output voltage at idle V1.3 - 1.7 at idle*
1.7 - 2.1 at 2,500 rpm*
*: Engine is warmed up sufficiently and running under no-load.
ENGINE COOLANT TEMPERATURE
SENSOR
Temperature ÉC (ÉF) Resistance
20 (68) 2.1 - 2.9 kW
50 (122) 0.68 - 1.00 kW
90 (194) 0.236 - 0.260 kW
FUEL PUMP
Resistance [at 25ÉC (77ÉF)]W0.2 - 5.0
IACV-AAC VALVE
Resistance [at 25ÉC (77ÉF)]WApproximately 10.0
INJECTOR
Resistance [at 25ÉC (77ÉF)]W10-14
RESISTOR
Resistance [at 25ÉC (77ÉF)] kWApproximately 2.2
THROTTLE POSITION SENSOR
Throttle valve conditions Resistance [at 25ÉC (77ÉF)]
Completely closed Approximately 0.6 kW
Partially open 0.6 - 4.0 kW
Completely open Approximately 4.0 kW
HEATED OXYGEN SENSOR HEATER
Resistance [at 25ÉC (77ÉF)]W2.3 - 4.3
INTAKE AIR TEMPERATURE SENSOR
Temperature ÉC (ÉF) Resistance
20 (68) 2.1 - 2.9 kW
80 (176) 0.27 - 0.38 kW
SERVICE DATA AND SPECIFICATIONS (SDS)KA
EC-232