3308463 - 1040A fuel tank and components (Automatic transmission)
COMPONENT DESCRIPTION
ELECTRIC FUEL PUMP
Specifcations
System specificationsThe fuel pump forms a single assembly with the fuel gauge sender unit and fuel filter; the components cannot be replaced individually.
Operation
Operating principleThe impeller (1) rotates, driven by the motor, creating volumes (2) which move from the inlet port (3) to the supply port (4).These volumes are defined by rollers (5) which, whilst the motor is rotating, adhere to the outer ring (6).The pump has two valves, one single-acting valve to prevent the fuel circuit from being drained (with the pump not working) and an excess pressure valve (7) which recirculates the supply when the pressure exceeds 5 bar.
INERTIA SWITCH
Specifcations
OperationIn the event of a crash, the inertia switch, fitted under the driver's seat, breaks the fuel pump's connection to earth and consequently the supply to the fuel injection system.Composition
Operating principleA steel ball (1) mounted in a conical housing (2) is normally locked by the attraction force of an adjacent magnet.Under specific acceleration loads, the ball is released from the magnetic lock and gradually emerges from the conical housing in an upward movement, following the angle of the cone.Above the ball, there is a quick-trip mechanism (3) which forms the normally closed (N.C.) electric circuit.When the mechanism is struck by the ball, it changes position from N.C. circuit to normally open (N.O.), breaking the fuel pump's earth circuit.The switch can be reset by pressing a button protected by a soft cover (4). | After a crash, even if minor, if a smell of fuel or fuel leaks are perceived, do not reset the switch, but seek the cause of the fault and eliminate it, in order to avoid risks of fire. Otherwise, if there are no leaks and the vehicle can be restarted, press the button to reactivate the pump. |
