11-05-2011, 12:05 PM
PRESENTED BY
JONEY THAKUR
[attachment=13533]
ABSTRACT
The basic idea behind MPFI (Multipoint fuel injection system) technology is to have the proper air fuel ratio in order to meet the modern exhaust emission demands. In addition to above MPFI provides economical fuel consumption because it is electronic controlled system which provides us with better control over mixing and supply of fuel as compared to traditional fuel supply system.
INTRODUCTION
The Multi-Point Electronic Fuel Injection (EFI) system is an electronically controlled system which combines electronic sequential fuel injection and electronic spark advance systems. Main sub-systems consist of: air induction, fuel delivery, fuel control, emission control, Electronic control Unit (ECU), data sensors and switches. Air induction system includes air cleaner, throttle body, Throttle Position Sensor (TPS) and the Idle Speed Stepper (ISS) motor. Fuel delivery system provides fuel from fuel pump to the fuel control system. Fuel system is composed of an in-tank electric fuel pump, fuel filter and return line. Power is provided to operate fuel pump through a fuel pump relay located on right inner fender panel.
pressure of 31-39 psi (2.1-2.7 kg/cm). In addition to the regulator, fuel system consists of the fuel rail and 4 fuel injectors. On MPI engine, ECU controls EGR/EVAP solenoid operation. The ECU is a digital microprocessor computer. ECU receives input signals from various switches and sensors. ECU then computes fuel injector pulse width ("on" time), spark advance, ignition module dwell, idle speed, canister purge cycles, EGR flow and feedback Control from this information.
Components of MPFI
Air intake system.
Fuel delivery & fuel control system.
Electronic control system.
Emission control system.
Air intake system
Air is drawn into combustion chamber through air cleaner and intake manifold. Amount of air entering engine is controlled by position of throttle body valve. Throttle body houses throttle position sensor (TPS) and idle speed solenoid (ISS) motor. TPS is an electrical resistor which is connected to throttle valve. TPS transmits a signal to ECU in relation to throttle valve angle. This signal is used in calculations to determine injector pulse width to provide adequate air/fuel mixture.
Fuel delivery & fuel control system
Power to fuel pump relay is supplied from ignition switch when in "ON" or "START" position, at which time the ECU supplies a ground for fuel pump relay. When relay contacts are closed, power is applied to fuel pump. Fuel is drawn through one end of a roller-type electric fuel pump, compressed and forced out opposite end. Pump capacity is greater than maximum engine consumption so that pressure in fuel control system handles actual fuel delivery into the engine. Fuel pressure regulator maintains a constant fuel system is always maintained.
Fuel control system handles actual delivery of fuel to engine. See Fig. 1. Fuel from fuel pump enters fuel rail, injectors and pressure regulator. Based upon a manifold vacuum signal, pressure regulator maintains a constant fuel pressure in fuel system of approximately 31-39 psi (2.1-2.7 kg/cm ) by allowing excess fuel to return to fuel tank.
Fuel injectors are electrically operated solenoid valves which are energized by the ECU. The ECU determines injector pulse width ("on" time) based upon input from the various sensors.
Electronic control system
ECU controls EGR valve and fuel evaporative operation. By energizing the EGR/EVAP solenoid, vacuum is shut off, making this system non-operative. When engine reaches normal operating temperatures, ECU de-energizes solenoid. When de-energized, solenoid allows vacuum to flow to EGR valve. ECU will energize solenoid whenever EGR action is undesirable, during idle, cold engine operation, wide open throttle and rapid acceleration or deceleration.
Electronic control system includes following parts:-
ECU (Electronic control unit).
Up-shift indicator.
Data sensors & switches
JONEY THAKUR
[attachment=13533]
ABSTRACT
The basic idea behind MPFI (Multipoint fuel injection system) technology is to have the proper air fuel ratio in order to meet the modern exhaust emission demands. In addition to above MPFI provides economical fuel consumption because it is electronic controlled system which provides us with better control over mixing and supply of fuel as compared to traditional fuel supply system.
INTRODUCTION
The Multi-Point Electronic Fuel Injection (EFI) system is an electronically controlled system which combines electronic sequential fuel injection and electronic spark advance systems. Main sub-systems consist of: air induction, fuel delivery, fuel control, emission control, Electronic control Unit (ECU), data sensors and switches. Air induction system includes air cleaner, throttle body, Throttle Position Sensor (TPS) and the Idle Speed Stepper (ISS) motor. Fuel delivery system provides fuel from fuel pump to the fuel control system. Fuel system is composed of an in-tank electric fuel pump, fuel filter and return line. Power is provided to operate fuel pump through a fuel pump relay located on right inner fender panel.
pressure of 31-39 psi (2.1-2.7 kg/cm). In addition to the regulator, fuel system consists of the fuel rail and 4 fuel injectors. On MPI engine, ECU controls EGR/EVAP solenoid operation. The ECU is a digital microprocessor computer. ECU receives input signals from various switches and sensors. ECU then computes fuel injector pulse width ("on" time), spark advance, ignition module dwell, idle speed, canister purge cycles, EGR flow and feedback Control from this information.
Components of MPFI
Air intake system.
Fuel delivery & fuel control system.
Electronic control system.
Emission control system.
Air intake system
Air is drawn into combustion chamber through air cleaner and intake manifold. Amount of air entering engine is controlled by position of throttle body valve. Throttle body houses throttle position sensor (TPS) and idle speed solenoid (ISS) motor. TPS is an electrical resistor which is connected to throttle valve. TPS transmits a signal to ECU in relation to throttle valve angle. This signal is used in calculations to determine injector pulse width to provide adequate air/fuel mixture.
Fuel delivery & fuel control system
Power to fuel pump relay is supplied from ignition switch when in "ON" or "START" position, at which time the ECU supplies a ground for fuel pump relay. When relay contacts are closed, power is applied to fuel pump. Fuel is drawn through one end of a roller-type electric fuel pump, compressed and forced out opposite end. Pump capacity is greater than maximum engine consumption so that pressure in fuel control system handles actual fuel delivery into the engine. Fuel pressure regulator maintains a constant fuel system is always maintained.
Fuel control system handles actual delivery of fuel to engine. See Fig. 1. Fuel from fuel pump enters fuel rail, injectors and pressure regulator. Based upon a manifold vacuum signal, pressure regulator maintains a constant fuel pressure in fuel system of approximately 31-39 psi (2.1-2.7 kg/cm ) by allowing excess fuel to return to fuel tank.
Fuel injectors are electrically operated solenoid valves which are energized by the ECU. The ECU determines injector pulse width ("on" time) based upon input from the various sensors.
Electronic control system
ECU controls EGR valve and fuel evaporative operation. By energizing the EGR/EVAP solenoid, vacuum is shut off, making this system non-operative. When engine reaches normal operating temperatures, ECU de-energizes solenoid. When de-energized, solenoid allows vacuum to flow to EGR valve. ECU will energize solenoid whenever EGR action is undesirable, during idle, cold engine operation, wide open throttle and rapid acceleration or deceleration.
Electronic control system includes following parts:-
ECU (Electronic control unit).
Up-shift indicator.
Data sensors & switches
