Lotus TURBO ESPRIT Service Manual page 396

Page
24
SECTION LD
LD. 20
-
EVAPORATIVE LOSS
SYSTEM
The fuel evaporative loss system includes a charcoal canister, one way valve, and
crankcase breather va h e .
Charcoal Canister
The breather pipes fro-m the fuel tank filler necks are routed via a roll-over valve
(to prevent fuel spillage
if
the car i s inverted) to p o r t ' ~ ~ ' o n the charcoal canister,
where the fumes are absorbed i n charcoal before being purged into the engine.
Similarly, when the engine
i s
stopped, fumes from the intake system are vented to
the canister via a hose linking the airflow sensor lower body to canister port
'C'
.
I n order to cleanse the charcoal of fuel absorbed i n this manner, arrangements
are made for fresh a i r to be drawn through the canister and consumed by the engine.
Two different connections are used to purge the canister under different engine
operating conditions.
Port
'PI
on the canister i s connected via a one way valve to the inlet manifold cold
start a i r rail, such that when the engine
i s
running a t small throttle opening, or on
overun,
(i
.e
.
with high manifold vacuum) air
i s
drawn through the canister and one
way valve into the inlet manifold, and i s then consumed by the engine.