Nissan Primera P11. Instruction — part 207
I
At high engine speeds.
I
When the engine coolant temperature becomes excessively high.
I
When operating power steering during low engine speed or low vehicle speed.
I
When engine speed is excessively low.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTION
NCEC0017
Input/Output Signal Chart
NCEC0017S01
Sensor
Input Signal to ECM
ECM func-
tion
Actuator
Vehicle speed sensor or ABS actuator and
electric unit (control unit)
Vehicle speed
Fuel cut
control
Injectors
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 “Multiport Fuel Injection (MFI) System”,
EC-SR-23.
Evaporative Emission System
DESCRIPTION
NCEC0018
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 tank
Air
Fuel vapor
EVAP
canister
SEF916W
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION
SR20DE
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.
INSPECTION
NCEC0019
EVAP Canister
NCEC0019S01
Check 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)
NCEC0019S03
1.
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:
−6.0 to −3.5 kPa (−0.060 to −0.035 bar, −0.061 to
−0.036 kg/cm
2
, −0.87 to −0.51 psi)
3.
If out of specification, replace fuel filler cap as an assembly.
Evaporative Emission (EVAP) Canister Purge Volume
Control Solenoid Valve
NCEC0019S07
Refer to EC-SR-250.
SEF917W
SEF918W
SEF943S
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION
SR20DE
Evaporative Emission System (Cont’d)
EC-28
EVAPORATIVE EMISSION LINE DRAWING
NCEC0020
NOTE:
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 DESCRIPTION
SR20DE
Evaporative Emission System (Cont’d)
EC-29
Positive Crankcase Ventilation
DESCRIPTION
NCEC0022
This system returns blow-by gas to the intake collector.
The positive crankcase ventilation (PCV) valve is provided to conduct crankcase blow-by gas to the intake
manifold.
During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the PCV
valve.
Normally, the capacity of the valve is sufficient to handle any blow-by and a small amount of ventilating air.
The ventilating air is then drawn from the air duct into the crankcase. In this process the air passes through
the hose connecting air inlet tubes to rocker cover.
Under full-throttle condition, the manifold vacuum is insufficient to draw the blow-by flow through the valve.
The flow goes through the hose connection in the reverse direction.
On vehicles with an excessively high blow-by, the valve does not meet the requirement. This is because some
of the flow will go through the hose connection to the intake collector under all conditions.
INSPECTION
NCEC0023
PCV (Positive Crankcase Ventilation) Valve
NCEC0023S01
With engine running at idle, remove PCV valve from breather sepa-
rator. A properly working valve makes a hissing noise as air passes
through it. A strong vacuum should be felt immediately when a fin-
ger is placed over the valve inlet.
Ventilation Hose
NCEC0023S02
1.
Check hoses and hose connections for leaks.
2.
Disconnect all hoses and clean with compressed air. If any
hose cannot be freed of obstructions, replace.
SEF921W
SEC137A
ET277
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION
SR20DE
Positive Crankcase Ventilation
EC-30
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