System Operation

The fuel pump is a variable-speed rotary-vane type, which operates in a fuel pump module located in the right-hand (RH) side of the fuel tank. A venturi transfer pump is located in the left-hand (LH) side of the tank and secured to the internal carrier. The fuel pump module is secured in the fuel tank with a bayonet style locking ring that is welded into the tank structure. The fuel pump module has an integral top plate for the external pipe work and electrical connectors.

Fuel level is biased towards the right-hand (RH) compartment in the fuel tank by circulating the fuel through internal crossover pipes via the jet pump, which also serves to deliver a constant supply of fuel to the transfer pump and swirl pot assembly. High pressure fuel from the fuel pump is directed through the jet pump's orifice, creating a low pressure area to be formed around the orifice. The fuel is drawn into this low pressure area and directed into the swirl pot delivery pipes. This is achieved using the cross-over pipe from the left-hand (LH) module and a direct link pipe from the right-hand (RH) module.

Fuel is pumped from the fuel pump to the fuel rail via the pressure relief valve.

The pressure relief valve assists engine starting by retaining a pre-set fuel pressure in the supply pipe and fuel rail. The pressure relief valve also limits fuel rail pressure due to temporary vapor increase in hot conditions and pressure caused by sudden load changes, for example, a fully open to closed throttle transition.

To meet on-board refueling vapor recovery (ORVR) requirements, the fuel tank and associated components are designed to minimize fuel vapor loss during refueling. This is achieved by preventing fuel vapor from the fuel tank venting directly to the atmosphere. Instead fuel vapor is directed into the evaporative emission (EVAP) charcoal canister where it is stored before being purged at intervals to the engine's intake manifold.