Page 659 of 1767
Engine Fuel & Emission Control System
MEC031E
PRECAUTIONS AND PREPARATIONTD27Ti
EC-297
Page 662 of 1767
Engine Control Component Parts Location
YEC234A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMTD27Ti
EC-300
Page 663 of 1767
NEF757
ENGINE AND EMISSION CONTROL OVERALL SYSTEMTD27Ti
Engine Control Component Parts Location
(Cont'd)
EC-301
Page 664 of 1767
Circuit Diagram
YEC140A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMTD27Ti
EC-302
Page 665 of 1767
System Diagram
YEC235A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMTD27Ti
EC-303
Page 666 of 1767
Vacuum Hose Drawing
q1Throttle body control valve actuator
to throttle body control solenoid
valve
q
2EGR valve to 3-way connector
q
3EGRC-solenoid valve A to 3-way
connector-1q
4EGRC-solenoid valve B to 3-way
connector-1
q
5Throttle body control solenoid
valve to 2-way connector-2
q
6EGRC-solenoid valve A to 3-way
connector-2q
7Tube to 3-way connector-2
q
8Tube to vacuum pump
q
9Tube to brake booster
Refer to ªSystem Diagramº, on previous page for vacuum control system
NEF759
ENGINE AND EMISSION CONTROL OVERALL SYSTEMTD27Ti
EC-304
Page 667 of 1767
System Chart
Crankshaft position sensor
(TDC)E
ECM
Control sleeve position sensorE
Fuel temperature sensorE
Mass air flow sensorE
Engine coolant temperature sen-
sorE
Needle lift sensorE
Accelerator position sensorE
Accelerator position switchE
Air conditioner switchE
Ignition switchE
Battery voltageE
Vehicle speed sensorE
Brake switchE
Atmospheric pressure sensor
(inside ECM)E
EFuel injection controlEElectric governor
EFuel injection timing controlEInjection timing control valve
EFuel cut controlEFuel cut solenoid valve
EGlow control systemEGlow relay & glow lamp
EOn board diagnostic systemEMalfunction indicator lamp
(On the instrument panel)
EEGR valve & Throttle control
valve controlEEGRC-solenoid valve A, B and
throttle control solenoid valve
(models for Germany)
EAir conditioning cut controlEAir conditioner relay
ENGINE AND EMISSION CONTROL OVERALL SYSTEMTD27Ti
EC-305
Page 668 of 1767

Fuel Injection System
SYSTEM DESCRIPTION
Three 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. The ECM performs duty cycle
control on the electric governor (built into the fuel injection pump) according to sensor signals to compensate
the amount of fuel injected to the preset value.
START CONTROL
Input/output signal line
Engine coolant temperature sensorEEngine coolant temperature
ECM
EElectric
governorCrankshaft position sensor (TDC)EEngine speed
Control sleeve position sensor
EControl sleeve position
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 a value between 800 rpm and 1,200 rpm, which is deter-
mined by the engine coolant temperature and shifts the control to
the normal or idle control.
SEF648S
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONTD27Ti
EC-306