NISSAN ALMERA 2001 Service Manual

HATCHBACKNJEC0608S02
NEF342A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMYD
Circuit Diagram (Cont'd)
EC-607

System DiagramNJEC0609
NEF343A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMYD
System Diagram
EC-608

System ChartNJEC0611
Input (Sensor) ECM Function Output (Actuator)
+Electronic control fuel injection pump
+Crankshaft position sensor (TDC)
+Engine coolant temperature sensor
+Accelerator position sensor
+Accelerator position switch
+Park/Neutral position (PNP) switch*
+Ignition switch
+Battery voltage
+Vehicle speed sensor
+Air conditioner switch
+Mass air flow sensor
+Stop lamp switchFuel injection controlElectronic control fuel injection
pump
Fuel injection timing controlElectronic control fuel injection
pump
Fuel cut controlElectronic control fuel injection
pump
Glow control system Glow relay & glow lamp
On board diagnostic system MI (On the instrument panel)
EGR volume control EGR volume control valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
*: If so equipped
ENGINE AND EMISSION CONTROL OVERALL SYSTEMYD
System Chart
EC-609

Fuel Injection Control System
DESCRIPTIONNJEC0612System DescriptionNJEC0612S01Three types of fuel injection control are provided to accommodate engine operating conditions; normal control,
idle control and start control. The ECM determines the appropriate fuel injection control. Under each control,
the amount of fuel injected is compensated to improve engine performance.
Pulse signals are exchanged between ECM and electronic control fuel injection pump (control unit is built-in).
The fuel injection pump control unit performs duty control on the spill valve (built into the fuel injection pump)
according to the input signals to compensate the amount of fuel injected to the preset value.
Start ControlNJEC0612S02Input/Output Signal ChartNJEC0612S0201
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (start
control)Electronic control fuel
injection pump Crankshaft position sensor (TDC) Engine speed
Ignition switch Start signal
SEF648S
When the ECM receives a start signal from the ignition switch, the ECM adapts the fuel injection system for
the start control. The amount of fuel injected at engine starting is a preset program value in the ECM. The
program is determined by the engine speed and engine coolant temperature.
For better startability under cool engine conditions, the lower the coolant temperature becomes, the greater
the amount of fuel injected. The ECM ends the start control when the engine speed reaches the specific value,
and shifts the control to the normal or idle control.
Idle ControlNJEC0612S03Input/Output Signal ChartNJEC0612S0301
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (Idle con-
trol)Electronic control fuel
injection pump Crankshaft position sensor (TDC) Engine speed
Battery Battery voltage
Accelerator position switch Idle position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
When the ECM determines that the engine speed is at idle, the fuel injection system is adapted for the idle
control. The ECM regulates the amount of fuel injected corresponding to changes in load applied to the engine
to keep engine speed constant. The ECM also provides the system with a fast idle control in response to the
engine coolant temperature signal.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Fuel Injection Control System
EC-610

Normal ControlNJEC0612S04Input/Output Signal ChartNJEC0612S0401
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (TDC) Engine speedFuel injection
control (Normal
control)Electronic control fuel
injection pump
Accelerator position sensor Accelerator position
SEF649S
The amount of fuel injected under normal driving conditions is determined according to sensor signals. The
crankshaft position sensor (TDC) detects engine speed and the accelerator position sensor detects accelera-
tor position. These sensors send signals to the ECM.
The fuel injection data, predetermined by correlation between various engine speeds and accelerator positions,
are stored in the ECM memory, forming a map. The ECM determines the optimal amount of fuel to be injected
using the sensor signals in comparison with the map.
Maximum Amount ControlNJEC0612S05Input/Output Signal ChartNJEC0612S0501
Sensor Input Signal to ECM ECM Function Actuator
Mass air flow sensor Amount of intake air
Fuel injection
control (Maxi-
mum amount
control)Electronic control fuel
injection pump Engine coolnat temperature sensor Engine coolant temperature
Crankshaft position sensor (TDC) Engine speed
Accelerator position sensor Accelerator position
The maximum injection amount is controlled to an optimum by the engine speed, intake air amount, engine
coolant temperature, and accelerator opening in accordance with the driving conditions.
This prevents the oversupply of the injection amount caused by decreased air density at a high altitude or
during a system failure.
Deceleration ControlNJEC0612S06Input/Output Signal ChartNJEC0612S0601
Sensor Input Signal to ECM ECM Function Actuator
Accelerator position switch Accelerator positionFuel injection
control (Decel-
eration control)Electronic control fuel
injection pump
Crankshaft position sensor (TDC) Engine speed
The ECM sends a fuel cut signal to the electronic control fuel injection pump during deceleration for better
fuel efficiency. The ECM determines the time of deceleration according to signals from the accelerator posi-
tion switch and crankshaft position sensor (TDC).
Fuel Injection Timing Control System
DESCRIPTIONNJEC0613The target fuel injection timing in accordance with the engine speed and the fuel injection amount are recorded
as a map in the ECM beforehand. The ECM and the injection pump control unit exchange signals and per-
form feedback control for optimum injection timing in accordance with the map.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Fuel Injection Control System (Cont'd)
EC-611

Air Conditioning Cut Control
DESCRIPTIONNJEC0614Input/Output Signal ChartNJEC0614S01
Sensor Input Signal to ECM ECM Function Actuator
Air conditioner switch Air conditioner ªONº signal
Air conditioner
cut controlAir conditioner relay Accelerator position sensor Accelerator valve opening angle
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
System DescriptionNJEC0614S02This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds.
When engine coolant temperature becomes excessively high, the air conditioner is turned off. This continues
until the engine coolant temperature returns to normal.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTIONNJEC0615Input/Output Signal ChartNJEC0615S01
Sensor Input Signal to ECM ECM Function Actuator
Vehicle speed sensor Vehicle speed
Fuel cut controlElectronic control fuel
injection pump Accelerator position switch Accelerator position
Crankshaft position sensor (TDC) Engine speed
If the engine speed is above 2,800 rpm with no load (for example, in neutral and engine speed over 2,800
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 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªFuel Injection Control Systemº,
EC-610.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Air Conditioning Cut Control
EC-612

SEF440Z
Crankcase Ventilation System
DESCRIPTIONNJEC0616In this system, blow-by gas is sucked into the air duct after oil
separation by oil separator in the rocker cover.
SEC692
INSPECTIONNJEC0617Ventilation HoseNJEC0617S011. 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.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Crankcase Ventilation System
EC-613

Injection Tube and Injection Nozzle
REMOVAL AND INSTALLATIONNJEC0618CAUTION:
+Do not disassemble injection nozzle assembly. If NG,
replace injection nozzle assembly.
+Plug flare nut with a cap or rag so that no dust enters the
nozzle. Cover nozzle tip for protection of needle.
JEF443Z
JEF340Y
Injection TubeNJEC0618S01RemovalNJEC0618S01011. Mark the cylinder Nos. to the injection tubes, then disconnect
them.
+Marking should be made at proper locations and by the
proper method, so that they are not erased by fuel, etc.
2. Remove the clamps, then disconnect the tubes one by one.
+The intake manifold is removed for explanation in the figure.
BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle
EC-614

JEF341Y
InstallationNJEC0618S01021. Referring to the figure and the marking which were made for
installation, connect the injection tubes to all the cylinders.
2. Connect temporarily the tubes to the cylinder head side only
by screwing 2 to 3 turns. Make sure that all tubes can be con-
nected to the pump side also.
3. Then, tighten the flare nuts of the cylinder head side and pump
side, starting from the opposite side from you.
JEF444Z
4. Attach the injection tube clamp in the direction shown in the
figure.
5. Insert tightening bolts of the clamp (4-tube type) from the rear
to the front of the engine.
JEF343Y
Injection Nozzle Oil SealNJEC0618S02RemovalNJEC0618S0201Using a tool such as a flat-bladed screwdriver, pry the flange of the
seal, then remove it.
Installation
NJEC0618S02021. After the high-pressure injection nozzle assembly is installed,
push the seal from the cylinder head side until it contacts the
flange.
2. Make sure that the garter spring of the seal on the high-pres-
sure injection nozzle assembly side is not falling.
+Replace the oil seal with new one when the high-pressure
injection nozzle assembly is removed. (It is not necessary
to replace the oil seal when only injection tubes are
removed.)
BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle (Cont'd)
EC-615

JEF344Y
Spill TubeNJEC0618S03RemovalNJEC0618S0301Loosen and remove the mounting bolts and flare nuts in the
reverse order of the numbers in the figure.
+When the flare nuts are loosened, hold the head of hexagonal
retaining bolts (head inside) using a wrench.
Installation
NJEC0618S03021. Tighten the flare nuts and mounting bolts in the numerical
order shown in the figure.
+When the flare nuts are tightened, hold the head of the hex-
agonal retaining bolts (head inside) using a wrench.
2. To prevent interference with the rocker cover, place the spill
gasket joint within the range shown by the arrow, then tighten
the mounting bolts. (Be especially careful about No. 2 and 4
cylinders.)
+After the spill tube is installed, check the airtightness of
the spill tube.
+After the bolts are tightened, the joint of the spill tube gasket
might be broken. However, this will not affect function.
JEF345Y
High Pressure Injection Nozzle AssemblyNJEC0618S04RemovalNJEC0618S04011. Remove the nozzle support, then pull out the high-pressure
injection nozzle assembly by turning it clockwise/
counterclockwise.
2. Using a tool such as a flat-head screwdriver, remove the cop-
per washer inside the cylinder head.
CAUTION:
Do not disassemble the high-pressure injection nozzle.
Installation
NJEC0618S04021. Insert the nozzle gasket to the cylinder head hole.
2. Attach the O-ring to the mounting groove of the nozzle side,
then insert it in the cylinder head.
TEST AND ADJUSTMENTNJEC0619WARNING:
When using nozzle tester, be careful not to allow diesel fuel
sprayed from nozzle to contact your hands or body, and make
sure your eyes are properly protected with goggles.
BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle (Cont'd)
EC-616