Volvo 164 Owner's Manual page 31

TECHNICAL DESCRIPTION
Fuel system
This engine is fitted with an electronic fuel
i njection system.
This system includes an electronic control
unit (7) that converts the impulses from
the various sensors in the engine to con-
trol signals which regulate the six solenoid-
actuated fuel injectors (15). The control
signals influence the opening times of the
i njectors and thereby the amount of fuel
i njected.
The mixture of fuel and air is modified the
whole time according to the conditions
under which the engine is running. Engine
speed is governed by the triggering con-
tacts (13) in the distributor, the operating
temperature by the sensor (17) for the
coolant, the temperature of the induced
air by the sensor (1) and the engine load
by the pressure sensor (5) which is con-
nected to the inlet duct. In addition, the
control unit is provided with information
concerning the position of the throttle
valve by means of the throttle valve switch
(2). This information is "computerized" in
the control unit and re-transmitted in the
form of control impulses to the injectors.
Fuel is injected into the inlet ports in the
cylinder head just before the intake valves.
The fuel is delivered to the injectors via
an electric fuel pump (12) which main-
tains a constant pressure of 2.0 kp/cm
psi) in the fuel line with the help of a
pressure regulator (14).
30
Principle of operation, fuel injection system
1. Temperature sensor for induction air
2. Throttle valve switch
3. Throttle housing
2 4. Cold start valve
(30
5. Pressure sensor
6. I nlet duct
7. Control unit (electronic)
8. Battery
9. Fuel tank
1 0. Fuel filter, suction side
11. Fuel filter, discharge side
'
Fuel pump
1 2.
1 3. Triggering contacts in distributor
Pressure regulator
1 4.
1 5. I njectors
1 6. Thermal timer contact
1 7. Temperature sensor for coolant
1 8. Auxiliary air regulator
1 9. I dling adjusting screw
Partial vacuum in inlet duct
Fuel at atmospheric pressure
2
Fuel below 2.0 kp/cm (30 psi)
overpressure