1999 NISSAN PRIMERA fuel pressure

Multiport Fuel Injection (MFI) System
DESCRIPTIONNCEC0014Input/Output Signal ChartNCEC0014S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed and piston position
Fuel injec-
tion & mix-
ture ratio
controlInjector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 (front) Density of oxygen in exhaust gas
Throttle position sensorThrottle position
Throttle valve idle position
PNP switch Gear position
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Ignition switch Start signal
Air conditioner switch Air conditioner operation
Knock sensor Engine knocking condition
Electrical load Electrical load signal
Battery Battery voltage
Power steering oil pressure switch Power steering operation
Heated oxygen sensor 2 (rear)* Density of oxygen in exhaust gas
* Under normal conditions, this sensor is not for engine control operation.
Basic Multiport Fuel Injection SystemNCEC0014S02The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the camshaft position sensor and the mass air
flow sensor.
Various Fuel Injection Increase/Decrease CompensationNCEC0014S03In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.

IDuring warm-up
IWhen starting the engine
IDuring acceleration
IHot-engine operation
IWhen selector lever is changed from ªNº to ªDº (CVT models only)
IHigh-load, high-speed operation

IDuring deceleration
IDuring high engine speed operation
IDuring high vehicle speed operation (M/T models)
IExtremely high engine coolant temperature
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Multiport Fuel Injection (MFI) System
EC-23

System DescriptionNCEC0015S02
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of
the engine. The ignition timing data is stored in the ECM. This data forms the map shown above.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Com-
puting this information, ignition signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
AÉBTDC
During the following conditions, the ignition timing is revised by the ECM according to the other data stored
in the ECM.
IAt starting
IDuring warm-up
IAt idle
IAt low battery voltage
IDuring acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions.
If engine knocking occurs, the knock sensor monitors the condition. The signal is transmitted to the ECM. The
ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut Control
DESCRIPTIONNCEC0016Input/Output Signal ChartNCEC0016S01
Sensor Input Signal to ECMECM func-
tionActuator
Air conditioner switch Air conditioner ªONº signal
Air condi-
tioner cut
controlAir conditioner relay PNP switch Neutral position
Throttle position sensor Throttle valve opening angle
Camshaft position sensor Engine speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Power steering oil pressure switch Power steering operation
System DescriptionNCEC0016S02This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
IWhen the accelerator pedal is fully depressed.
IWhen cranking the engine.
SEF742M
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Distributor Ignition (DI) System (Cont'd)
EC-26

IAt high engine speeds.
IWhen the engine coolant temperature becomes excessively high.
IWhen operating power steering during low engine speed or low vehicle speed.
IWhen engine speed is excessively low.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTIONNCEC0017Input/Output Signal ChartNCEC0017S01
Sensor Input Signal to ECMECM func-
tionActuator
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Fuel cut
controlInjectors PNP switch Neutral position
Throttle position sensor Throttle position
Engine coolant temperature sensor Engine coolant temperature
Camshaft position sensor Engine speed
If the engine speed is above 3,950 rpm with no load, (for example, in Neutral and engine speed over 4,000
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,150 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªMultiport Fuel Injection (MFI) Systemº,
EC-SR-23.
Evaporative Emission System
DESCRIPTIONNCEC0018
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating.
EVAP canister purge volume control solenoid valve is controlled by ECM. When the engine operates, the flow
Intake manifold
Throttle body
Purge line
EVAP canister
purge volume
control solenoid
valve
Relief of vacuum
Sealing gas cap with
pressure relief valve
and vacuum relief
valve
Fuel tankAir
Fuel vapor EVAP
canister
SEF916W
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Air Conditioning Cut Control (Cont'd)
EC-27

rate of vapor controlled by EVAP canister purge volume control solenoid valve is proportionally regulated as
the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
INSPECTIONNCEC0019EVAP CanisterNCEC0019S01Check EVAP canister as follows:
1. Block port B. Orally blow air through port A. Check that air
flows freely through port C with check valve resistance.
2. Block port A. Orally blow air through port B. Check that air
flows freely through port C.
Fuel Tank Vacuum Relief Valve (Built into fuel filler cap)NCEC0019S031. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
Pressure:
16.0 - 20.0 kPa (0.16 - 0.20 bar, 0.163 - 0.204
kg/cm
2, 2.32 - 2.90 psi)
Vacuum:
þ6.0 to þ3.5 kPa (þ0.060 to þ0.035 bar, þ0.061 to
þ0.036 kg/cm
2, þ0.87 to þ0.51 psi)
3. If out of specification, replace fuel filler cap as an assembly.
Evaporative Emission (EVAP) Canister Purge Volume
Control Solenoid Valve
NCEC0019S07Refer to EC-SR-250.
SEF917W
SEF918W
SEF943S
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Evaporative Emission System (Cont'd)
EC-28

EVAPORATIVE EMISSION LINE DRAWINGNCEC0020NOTE:
Do not use soapy water or any type of solvent while installing
vacuum hoses or purge hoses.
SEF193X Intake manifold collector
Throttle body
Rear view (Left side)Rear view (Right side)
Intake manifold collector
Fuel pressure
regulator
To brake
booster
Air hose to
power steering
air valve
EVAP purge line to engine
Fuel filter
To EVAP
canister
(RHD models)
EVAP purge volume
control solenoid valve
To EVAP
canister
(LHD models)
Front view
EVAP purge
line to
engine
EVAP canister
(LHD models)
Power steering air valve
To intake manifold
collector
Air tube for power
steering air valve
To EVAP
canister
(RHD models)
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Evaporative Emission System (Cont'd)
EC-29

Fuel Pressure ReleaseNCEC0024Before disconnecting fuel line, release fuel pressure from fuel
line to eliminate danger.
WITH CONSULT-IINCEC0024S011. Start engine.
2. Perform ªFUEL PRES RELEASEº in ªWORK SUPPORTº
mode with CONSULT-II.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF.
WITHOUT CONSULT-IINCEC0024S021. Remove fuse for fuel pump. Refer to fuse block cover for fuse
location.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF and reconnect fuel pump fuse.
Fuel Pressure CheckNCEC0025IWhen reconnecting fuel line, always use new clamps.
IMake sure that clamp screw does not contact adjacent
parts.
IUse a torque driver to tighten clamps.
IUse Pressure Gauge to check fuel pressure.
IDo not perform fuel pressure check with system operat-
ing. Fuel pressure gauge may indicate false readings.
1. Release fuel pressure to zero.
2. Disconnect fuel hose between fuel filter and fuel tube (engine
side).
3. Install pressure gauge between fuel filter and fuel tube.
4. Start engine and check for fuel leakage.
5. Read the indication of fuel pressure gauge.
At idle speed:
With vacuum hose connected
Approximately 235 kPa (2.35 bar, 2.4 kg/cm
2,34
psi)
With vacuum hose disconnected
Approximately 294 kPa (2.94 bar, 3.0 kg/cm
2,43
psi)
PEF823K
Fuel pump fuse
Fuel pump
relay
Data link connector
SEF192X
Fuel filter
SEF194X
BASIC SERVICE PROCEDURESR20DE
Fuel Pressure Release
EC-31

If results are unsatisfactory, perform Fuel Pressure Regulator
Check, EC-SR-32.
Fuel Pressure Regulator CheckNCEC00261. Stop engine and disconnect fuel pressure regulator vacuum
hose from intake manifold.
2. Plug intake manifold with a rubber cap.
3. Connect variable vacuum source to fuel pressure regulator.
4. Start engine and read indication of fuel pressure gauge as
vacuum is changed.
Fuel pressure should decrease as vacuum increases. If results
are unsatisfactory, replace fuel pressure regulator.
IDo not reuse O-ring.
Injector
REMOVAL AND INSTALLATIONNCEC00271. Release fuel pressure to zero.
2. Disconnect fuel hoses and injector harness connectors.
3. Remove fuel tube assemblies with fuel injectors.
4. Expand and remove clips securing fuel injectors.
5. Extract fuel injectors straight from fuel tubes.
IBe careful not to damage injector nozzles during removal.
IDo not bump or drop fuel injectors.
IDo not disassemble or adjust fuel injectors.
6. Install fuel injectors with extra care for O-rings.
IDo not reuse O-rings.
IUse bare hands to install O-rings. Do not wear gloves.
IApply a coat of new engine oil (with a low viscosity of
5W-30, etc.) to O-rings before installation.
IDo not use solvent to clean O-rings and other parts.
IMake sure that O-rings and other parts are clean and free
from foreign particles.
IBe careful not to damage O-rings with service tools, clip
or finger nails. Do not expand or twist O-rings. If
stretched, do not insert them into fuel tubes immediately
after stretching.
IAlways insert O-rings straight into fuel tubes. Do not tilt
or rotate them during installation.
7. Position clips in grooves on fuel injectors.
IMake sure that protrusions of fuel injectors are aligned
with cutouts of clips after installation.
8. Align protrusions of fuel tubes with those of fuel injectors.
Insert fuel injectors straight into fuel tubes.
9. After properly inserting fuel injectors, check to make sure that
fuel tube protrusions are engaged with those of fuel injectors,
and that flanges of fuel tubes are engaged with clips.
SEF718B
SEF927W
BASIC SERVICE PROCEDURESR20DE
Fuel Pressure Regulator Check
EC-32

Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment
NCEC0028PREPARATIONNCEC0028S01IMake sure that the following parts are in good order.
a)Battery
b)Ignition system
c)Engine oil and coolant levels
d)Fuses
e)ECM harness connector
f)Vacuum hoses
g)Air intake system
(Oil filler cap, oil level gauge, etc.)
h)Fuel pressure
i)Engine compression
j)Throttle valve
k)EVAP system
IOn models equipped with air conditioner, checks should
be carried out while the air conditioner is ªOFFº.
IWhen checking idle speed on models equipped with CVT,
ignition timing and mixture ratio, checks should be carried
out while shift lever is in ªPº or ªNº position.
IWhen measuring ªCOº percentage, insert probe more
than 40 cm (15.7 in) into tail pipe.
ITurn off headlamps, heater blower, rear window defogger.
IOn vehicles equipped with daytime running light systems,
set lighting switch to the 1st position to light only small
lamps.
IKeep front wheels pointed straight ahead.
IIf engine stops immediately after starting or idle condition
is unstable, perform the following to initialize IACV-AAC
valve:
a)Stop engine and wait 9 seconds.
b)Turn ignition ªONº and wait 1 second.
c)Turn ignition ªOFFº and wait 9 seconds.
IMake the check after the cooling fan has stopped.
BASIC SERVICE PROCEDURESR20DE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment
EC-34