2. Replacement for carburetor.
EFI very precise, reliable & cost effective.
EFI provide correct A/F ratio.
Reduce exhaust pollution.
Increased engine power.
3. Single or Multi-point injection
Indirect or Direct injection
4. Injector located inside
throttle body.
Injector sprays fuel from
above throttle valve.
ECU control injector
openings.
5. Injector located below
Throttle valve.
Injector sprays fuel
Directly to ports.
ECU controls opening.
6. Injector is fixed to the top
of combustion chamber.
Fuel is injected above
Piston head.
Smaller combustion space,
better thermal efficiency.
7. Indirect Injection System
has a small swirl chamber
above the cylinder.
Fuel is injected in swirl
chamber.
Higher compression ratio
needed to aid starting.
8. Control electrical systems in motor vechile.
Determines the amount of fuel, ignition timing
and other parameters.
10. Sensors are electrical device.
It will change resistance with change in
condition.
Monitors operating condition and report to
Ecu.
11. Oxygen sensor
Throttle position sensor(TPS)
Engine Temperature sensor(ETS)
Inlet Air Temperature Sensor
Crank Shaft Position sensor
12. Measure oxygen content
Mounted on exhaust system
Output voltage changes with change in oxygen
content.
Lean mixture decreases voltage
Rich mixture increases voltage
13. Variable resistor connected to throttle plate.
Change in throttle angle =change in resistance.
Based on resistance , ECU richens or leans the
mixture.
14. Monitors the temperature of engine.
Exposed to engine coolant.
Engine cold = low resistance = rich mixture
Engine hot = high resistance = lean mixture
15. Measure the temperature of air entering the
engine.
Cold air = more Fuel for proper A/F ratio.
16. Detects engine speed
Change injector timing and position
Higher engine speed = more fuel
