Tank Venting System

When the engine is stopped, the tank is vented into a carbon canister which absorbs the vapors. The removal of fuel vapors in the carbon canister is accomplished with a hose system leading to the throttle housing. With the engine stopped, fuel vapors travel from fuel tank via expansion tank and rollover safety valve to the active carbon filter, which is installed in the right front wheel house.

The carbon canister has 2 connections. The unmarked connection is connected with the tank. The "IN" connection with the vent line runs back to the rear of the vehicle and exits into the open air underneath the bumper.

There are 3 valves to control the drawing off of fuel vapors and venting of the active carbon filter.

• Temperature Valve: Opens vacuum connection to switching valve when reaching a temperature of more than 130°F (58°C).
• Shift Valve: Opens or closes connection between active carbon filter and the control valve.
• Control Valve: Functions in accordance with the throttle valve position. If the throttle valve is closed, the control valve is also closed. It opens as the throttle valve opens.