GENERAL INFORMATION


The Multipoint Fuel Injection System consists of sensors which detect the engine conditions, the engine-ECU which controls the system based on signals from these sensors, and actuators which operate under the control of the engine-ECU. The engine-ECU carries out activities such as fuel injection control, idle speed control and ignition timing control. In addition, the engine-ECU is equipped with several diagnosis modes which simplify troubleshooting when a problem develops.


FUEL INJECTION CONTROL


The injector drive times and injection timing are controlled so that the optimum air/fuel mixture is supplied to the engine to correspond to the continually-changing engine operation conditions.
A single injector is mounted at the intake port of each cylinder. Fuel is sent under pressure from the fuel tank by the fuel pump, with the pressure being regulated by the fuel pressure regulator. The fuel thus regulated is distributed to each of the injectors.
Fuel injection is normally carried out once for each cylinder for every two rotations of the crankshaft. The firing order is 1-3-4-2. This is called sequential fuel injection. The engine-ECU provides a richer air/fuel mixture by carrying out "open-loop" control when the engine is cold or operating under high load conditions in order to maintain engine performance. In addition, when the engine is warm or operating under normal conditions, the engine-ECU controls the air/fuel mixture by using the oxygen sensor signal to carry out "closed-loop" control in order to obtain the theoretical air/fuel mixture ratio that provides the maximum cleaning performance from the three way catalyst.

THROTTLE VALVE OPENING CONTROL


This system electronically controls the opening of the throttle valve. The engine-ECU detects the amount of travel of the accelerator pedal via the accelerator pedal position sensor, and controls the actuation of the throttle valve control servo, which is mounted on the throttle body, in order to attain the target throttle valve opening that has been predetermined in accordance with driving conditions.

IDLE SPEED CONTROL


The idle speed is kept at the optimum speed by controlling the amount of air that passes through the throttle valve in accordance with changes in idling conditions and engine load during idling.
The engine-ECU drives the throttle valve control servo to keep the engine running at the pre-set idle target speed in accordance with the engine coolant temperature and A/C and other electrical load. In addition, when the A/C switch is turned off and on while the engine is idling, the throttle valve control servo adjusts the throttle valve passes through air amount according to the engine load conditions to avoid fluctuations in the engine speed.

IGNITION TIMING CONTROL


The power transistor located in the ignition primary circuit turns ON and OFF to control the primary current flow to the ignition coil. This controls the ignition timing in order to provide the optimum ignition timing with respect to the engine operating conditions. The ignition timing is determined by the engine-ECU from the engine speed, intake air volume, engine coolant temperature and atmospheric pressure.

MIVEC (Continuous Variable Valve Lift and Valve Timing System)


MIVEC, consists of two systems shown below. The MIVEC controls the two systems in accordance with the engine load. It improves fuel the efficiency by reducing pumping loss, enhancing the expansion ratio and stabilising the combustion by means of controlling throttle valve opening in conjunction with these systems.
Continuous Variable Valve Lift System
Continuous Variable Valve Timing System

SELF-DIAGNOSIS FUNCTION




OTHER CONTROL FUNCTIONS



  1. Fuel Pump Control
    Turns the fuel pump relay ON so that current is supplied to the fuel pump while the engine is cranking or running.
  2. A/C Relay Control
    Turns the compressor clutch of the A/C ON and OFF.
  3. Oil Feeder Control Valve Control
    The engine-ECU carries out the duty control of the oil feeder control valve according to the operation condition. This varies the phase angle of the camshaft to optimize the valve timing.
  4. Alternator Output Current Control
    Prevents alternator output current from increasing suddenly and idle speed from dropping at times such as when the headlamp are turned on.
  5. Purge Control Solenoid Valve Control
    [Refer to GROUP 17 - Emission Control <MPI> - Evaporative Emission Control System - General Information (Evaporative Emission Control System) ].

GENERAL SPECIFICATIONS


Items
Specifications
Throttle body
Throttle bore mm
57
Throttle position sensor
Hall element type
Throttle valve control servo
DC motor type, having brushes
Engine-ECU
Identification No.
E6T79572 <M/T>
E6T79573 <CVT>
Sensors
Air flow sensor
Heat sensitizing type
Barometric pressure sensor
Semiconductor type
Intake air temperature sensor
Thermistor type
Engine coolant temperature sensor
Thermistor type
Oxygen sensor
Zirconia type
Accelerator pedal position sensor
Hall element type
Camshaft position sensor
Magneto resistance element type
Crank angle sensor
Magneto resistance element type
Detonation sensor
Piezoelectric type
Manifold absolute pressure sensor
Semiconductor type
Valve lift sensor
Hall element type
Brake booster pressure sensor
Semiconductor type
Actuators
Engine control relay
Contact switch type
Fuel pump relay
Contact switch type
A/C compressor relay
Contact switch type
Starter relay
Contact switch type
Injector relay
Contact switch type
Injector type and number
Electromagnetic type, 4
Injector identification mark
KME340C
Throttle valve control servo relay
Contact switch type
Oil feeder control valve
Duty cycle type solenoid valve
Purge control solenoid valve
Duty cycle type solenoid valve
Valve lift control relay
Contact switch type
Valve lift control motor
Brushless DC motor
Fuel pressure regulator
Regulator pressure kPa
324