NISSAN ALMERA N16 2001 Electronic Repair Manual

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-505

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-506

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-505.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Air Conditioning Cut Control
EC-507

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-508

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-509

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-510

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-511

JEF346Y
Inspection for Spill Tube AirtightnessNJEC0619S01Before the rocker cover is installed, perform the inspection as fol-
lows.
1. Connect the handy vacuum pump to the spill hose.
2. Check that the airtightness is maintained after the negative
pressure shown below is applied.
Standard:
±53.3 to ±66.7 kPa (±533 to ±667 mbar, ±400 to ±500
mmHg, ±15.75 to ±19.69 inHg)
JEF347Y
Air Bleeding of Fuel PipingNJEC0619S02After the repair, bleed air in the piping by pumping the priming
pump up and down until it becomes heavy.
JEF348Y
Injection Pressure TestNJEC0619S031. Install injection nozzle assembly to injection nozzle tester and
bleed air from flare nut.
2. Pump the tester handle slowly (one time per second) and
watch the pressure gauge.
3. Read the pressure gauge when the injection pressure just
starts dropping.
Initial injection pressure:
New
21,476 - 22,457 kPa (214.7 - 224.5 bar, 219 - 229
kg/cm
2, 3,114 - 3,256 psi)
Limit
18,275 kPa (182.7 bar, 186 kg/cm
2, 2,650 psi)
+The injection nozzle assembly has a 2-stage pressure injection
function. However, the judgement should be made at the first
stage of the valve opening pressure.
Always check initial injection pressure using a new nozzle.
BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle (Cont'd)
EC-512

SEF434Z
Spray Pattern TestNJEC0619S051. Check spray pattern by pumping tester handle one full stroke
per second.
NG spray pattern:
Does not inject straight and strong (B in the figure).
Fuel drips (C in the figure).
Does not inject evenly (D in the figure).
2. If the spray pattern is not correct, replace injection nozzle
assembly.
Electronic Control Fuel Injection Pump
REMOVAL AND INSTALLATIONNJEC0620
JEF350Y
RemovalNJEC0620S011. Remove the parts shown below.
+Engine hood
+Engine coolant (drain)
+Engine cover
+Heater pipe under intake manifold
+Injection tubes
+Right splash cover (with undercover)
+Right front wheel
BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle (Cont'd)
EC-513

JEF351Y
2. Disconnect the fuel hoses from the fuel injection pump.
3. Disconnect the harness connector from the fuel injection
pump.
+Disconnect the connector by pulling the connector stopper
fully.
+When the stopper is fully pulled, the connector will be discon-
nected together. For installation, push the connector half way
first, then press the stopper until it locks, so that the connec-
tor is connected together.
4. Remove the fuel injection pump rear bracket.
JEF352Y
5. Remove the front chain case.
+Move the power steering fluid reservoir tank from the bracket.
+Loosen and remove the mounting bolts in the reverse order of
the numbers shown in the figure.
+As for bolts 6, 10, and 11, remove with rubber washer because
there is not enough space for removing only the bolts.
CAUTION:
To prevent foreign objects from getting in the engine, cover
the opening during the removal of the front chain case.
JEF353Y
6. Adjust the No. 1 cylinder to the top dead center position.
+Turn the crankshaft pulley clockwise, then align the alignment
mark (punched mark) of the camshaft sprocket to the position
shown in the figure.
+There is no indicator on the crankshaft pulley.
+It is not necessary to mark the secondary timing chain for
removal because it can be matched by the link color for instal-
lation. However, the alignment mark on the fuel injection pump
sprocket is difficult to see; mark it if necessary.
JEF354Y
7. Remove the chain tensioner.
a. Push the plunger of the chain tensioner, then fix it with a tool
such as a push pin.
JEF355Y
b. Using the hexagon wrench (face to face: 5 mm) (SST), remove
the mounting bolts, then remove the chain tensioner.
+A multi-purpose tool may also be used.
BASIC SERVICE PROCEDUREYD
Electronic Control Fuel Injection Pump (Cont'd)
EC-514