Lotus Elise Service Notes page 356

D Lotus Service Notes
Section JH
The top side of the charcoal bed is connected via a port in the top of the canister, to atmosphere. A
purging port, controlled by a solenoid valve on the top of the canister, connects the tank vent and underside of
the charcoal bed with a port on the throttle body such that when the valve is open, the depression in the engine
intake draws air through the charcoal bed to purge the canister of vapour, and prepare the charcoal for further
adsorption.
Control System
The canister purge valve is controlled by the engine management ECM, which keeps the valve closed
(unenergised) when the engine is cold or idling in order to protect the catalyst and maintain idle quality. At
coolant temperatures above 75°C and engine speeds above 1600 rpm, the ECM opens the valve and allows
purging of the charcoal to take place, burning the resultant gas in the normal combustion process.
Roll Over Valve
The roll over valve is fitted on a bracket integral with the filler neck and is positioned above the neck
within the 'flying butress' of the rear clamshell. The clamshell must be removed (Sub-section BN.5) for access
to the valve.
Page 356 1998 / 03