Evaporative Loss System; System Operation; Fuel Tank Vents And Control Valves - Aston Martin V8 Vantage Workshop Manual

Fuel Tank and Lines (10.01)
Fuel (10.00)

Evaporative Loss System

Fuel vapour is displaced from the fuel tank during filling.
Vapour is also displaced due to fuel evaporation in higher
temperatures. Displaced fuel vapour is absorbed in the
carbon canister filter located on top of the fuel tank.
During normal engine running, absorbed fuel vapour is
purged from the carbon canister and mixed with the normal
fuel/air charge in the inlet manifold.

System Operation

Displaced fuel vapour leaves the fuel tank via the normally
open fuel level vent valve and the roll over valves. It passes
through the carbon canister where fuel hydrocarbons are
absorbed. Clean air leaves the system via the normally open
canister vent valve. This valve is only closed during
diagnostic pressure testing of the fuel system.
During normal engine running, the single vapour
management valve in the engine bay is periodically opened,
when negative pressure exists in the intake manifold,
allowing fresh air flow into the open canister vent valve,
through the carbon canister, through the vapour
management valve and into the primary inlet manifold. This
fresh air flow progressively purges any absorbed fuel vapour
from the carbon canister.

Fuel Tank Vents and Control Valves

10-1-6
On-Board Refuelling Vapour Recovery
All of the vapour displaced from the tank by refuelling passes
through a series of valves and through a carbon canister. This
filters out and stores all the fuel vapour and clean air exits the
carbon canister port.
Workshop Manual October 2005