0
TYPES OF EFI
EFI - Types of EF
I
EFI systems can be divided into two types
according to the method used to sense the
volume of intake air
:
1
. D-TYPE EFI (MANIFOLD PRESSURE
CONTROL TYPE
)
This type measures the strength of the vacuum
in the intake manifold, thereby sensing the
volume of air by its density
.
Ai
r
INTAKE MANIFOL
D
MANIFOL
D
PRESSURE
SENSO
R
1
I/
F
i
Detection
of intake
manifold
pressure
ENGIN
E
Engine spee
d
I
Fuel
AIR FLOW METE
R
INTAKE MANIFOL
D
ENGIN
E
Engine spee
d
ENGINE ECU
Injectio
n
INJECTO
R
Injection volume
&--
Fuel
control
OHP 4
3
Vane typ
e
ENGINE ECU
Injection volume control
OHP 4
3
MANIFOLD PRESSURE SENSOR
OHP 4
3
2
. L-TYPE EFI (AIR FLOW CONTROL
TYPE
)
This type directly senses the amount of air
flowing into the intake manifold by means of an
air flow meter
.
Hot-wire typ
e
AIR FLOW METE
R
Injectio
n
INJECTOR
Optical Karman
vo
rt
ex typ
e
Detection of
intak
e
air volume
OHP 4
3
OHP 4
3
52