Nissan Terrano r20e. Instruction — part 168

Fuel Injection Timing System

SYSTEM DESCRIPTION

The fuel injection timing system determines the optimal fuel injection timing, based on engine speed, injection
quantity, engine coolant temperature and atmospheric pressure. The timing is formed by a basic value (Basic
Control) and two correction values. By performing a duty cycle signal on the timing control valve, the ECM
allows the valve to provide optimal injection timing. The ECM also performs feedback control on the timing
control valve using the signal from the needle lift sensor which detects the actual fuel injection timing.

BASIC CONTROL

Input/output signal line

Crankshaft position sensor (TDC)

E

Engine speed

ECM

E

Injection
timing con-
trol valve

Needle lift sensor

E

Injection timing

Control sleeve position sensor

E

Control sleeve position

The optimal fuel injection timing data, predetermined in proportion
to engine speeds and amount of fuel injected, are stored in the
ECM memory. The ECM uses the data to control the fuel injection
timing.

HIGH ALTITUDE COMPENSATION

Input/output signal line

Crankshaft position sensor

E

Engine speed

ECM

E

Injection
timing
control
device

Control sleeve position sensor

E

Control sleeve position

Atmospheric pressure sensor

E

Atmospheric sensor

Needle lift sensor

E

Injection timing

Fuel temperature sensor

E

Fuel temperature

E

Electric
governor

For better drivability in high altitude areas, the fuel injection timing
is advanced and the fuel quantity is reduced according to the atmo-
spheric pressure.

SEF650S

ENGINE AND EMISSION BASIC CONTROL

SYSTEM DESCRIPTION

TD27Ti

EC-309

ENGINE COOLANT TEMPERATURE COMPENSATION (When starting)

Input/output signal line

Crankshaft position sensor (TDC)

E

Engine speed

ECM

E

Injection
timing con-
trol valve

Engine coolant temperature sensor

E

Engine coolant temperature

Needle lift sensor

E

Ignition timing

Ignition switch

E

Start signal

For better startability under cool engine conditions, the fuel injec-
tion timing is compensated according to the engine coolant tem-
perature.

ENGINE COOLANT TEMPERATURE COMPENSATION (During driving)

Input/output signal line

Crankshaft position sensor (TDC)

E

Engine speed

ECM

E

Injection
timing con-
trol valve

Engine coolant temperature sensor

E

Engine coolant temperature

Needle lift sensor

E

Injection timing

For better exhaust efficiency under cool engine conditions, the fuel
injection timing is controlled within a compensation range depend-
ing on the engine speed, engine coolant temperature and amount
of fuel injected.

MEC023E

SEF652S

ENGINE AND EMISSION BASIC CONTROL

SYSTEM DESCRIPTION

TD27Ti

Fuel Injection Timing System (Cont’d)

EC-310

Air Conditioning Cut Control

INPUT/OUTPUT SIGNAL LINE

Air conditioner switch

E

Air Conditioner “ON” signal

ECM

E

Air Condi-
tioner relay

Accelerator position sensor

E

Accelerator valve opening angle

Vehicle speed sensor

E

Vehicle speed

Engine coolant temperature sensor

E

Engine coolant temperature

SYSTEM DESCRIPTION

This 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 cool-
ant temperature returns to normal.

Fuel Cut Control (at high engine speed)

INPUT/OUTPUT SIGNAL LINE

Crankshaft position sensor (TDC)

E

Engine speed

ECM

E

Electric
governor

If the engine speed is above 5,500 rpm fuel will be cut off to keep
engine within its working range.
NOTE:
This function is different from deceleration control and fuel cut
solenoid valve control.

Glow Control

INPUT/OUTPUT SIGNAL LINE

Engine coolant temperature sensor

E

Engine coolant temperature

ECM

E

Glow relay

E

Glow plug

Ignition switch

E

Start signal

E

Glow lamp

Glow plug is heated in three-stage that is pre-glow, intermediate-
glow and after-glow. Glow time changes depending on engine cool-
ant temperature.

ENGINE AND EMISSION BASIC CONTROL

SYSTEM DESCRIPTION

TD27Ti

EC-311

Description

I

In this system blow-by gas is sucked into the air inlet pipe
through the control valve after oil separation by oil separator.

Blow-by Control Valve

I

Check control valve for clogging and abnormalities.

Ventilation Hose

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.

NEF760

MEC971D

NEF762

SEC692

CRANKCASE VENTILATION SYSTEM

TD27Ti

EC-312