Alfa Romeo 159 Training Material page 86

ENGINE
High pressure fuel circuit
SYSTEM ACTUATORS:
High pressure fuel pump
Injection piping
High pressure injector
Pressure regulator valve
Fuel high and low pressure line
Ignition coil module
High pressure fuel pump
OBJECTIVE: The high pressure fuel pump increases input fuel pressure (equal to 3.5 bars) to 120 bars for supplying
the rail. This pressure reduces pressure fluctuations inside the rail.
TECHNICAL SPECIFICATIONS:
Three cylinder, radial piston pump
3
Displacement 0.5 cm /rev
Pressure range 2 - 12 MPa, 0,4 MPa at start-up
Speed range
LIFESPAN OF COMPONENT: The specific tolerances of the component are designed to last for 10 years or 150,000
km.
WORKING CONDITIONS:
Fuel temperature during normal use maximum 80°C, not in use 100°C, maximum temperature of 130°C can be held
for 30 minutes.
Fuel vapours must not penetrate inside inlet area.
Two filters: main filter on supply line with 5 µm fine mesh and filter on connection with 30 µm fine mesh.
Admissible dynamic load <=600 m/s
REMOVAL/REFITTING: The pump is fitted on the head axially with respect to the camshaft with an Oldham clutch. It
is essential to lubricate the o-ring with engine oil (clean, no silicon). The Oldham clutch is joined without applying
force. Union with the head is obtained by applying a force not exceeding 200 N.
ADDITIONAL INDICATIONS: The pressure of the screws on the head must not exceed 360 N/mm^2. The Oldham
clutch and the bearing required continuous lubrication during operation. Replace the o-ring after each removal.
Handle the pump with care.
Injection piping
FUNCTION: To ensure supply of fuel in direct injection petrol systems.
FEATURES: Four fuel injectors, a pressure regulating valve and the pressure sensor are fitted on the fuel rail. The
rail is also fitted with a high pressure and a low pressure connector. The rail must be adequately flexible to damper
pressure oscillations generated by the fuel injections and by the high pressure pump operation. At the same time, it
must be stiff enough to rapidly respond to pressure variations during engine operation.
Traccia Didattica Alfa 159-en-ridotta
ALFA 159 TRAINING MATERIAL
40 - 3500 rpm.
2
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