Technical Changes As of MY 1996

EVAPORATIVE LOSS FLANGE TECHNICAL CHANGES
On all Sedan models, a steel evaporative loss flange replaces the previous plastic design. A new roll-over valve and fuel pump electrical connector are installed in grommets on the new flange. The flange locking ring is unchanged, but a revised flange to tank sealing arrangement means the two types of flange are not interchangeable.

TWIN CANISTER SYSTEM
In the USA, to comply with evaporative emissions and On-board Diagnostics legislation, a number of XJ6 Sedans constituting 20% of annual Sedan sales have a twin canister evaporative loss control system. The twin canister system provides further reductions in evaporative emissions and enables the Engine Control Module (ECM) to test for leaks equivalent to a hole of 1 mm (0.040in.) diameter minimum. Differences from the single canister system are detailed below:

Vapor Pipes
The flexible vapor pipes are changed to P-CAP to reduce losses through the pipe walls. Viton rubber hoses and hose clamps provide the in-line and component connections.





Carbon Canister
A second carbon canister is added to reduce the concentration of fuel in the vapor that vents to atmosphere. It is installed under the right rear seat pan and connected in series with the first canister.





Running Loss Control Valve
A normally open, running loss control valve replaces the vacuum/pressure relief valve (Rochester valve). The running loss control valve permits free venting of the tank, but prevents fuel entering the vent line during refueling.
During refueling, the incoming fuel creates a pressure differential between the tank interior and the filler neck. On sensing the pressure differential the valve closes, shutting-off the vent line.





Fuel Tank Pressure Sensor
A fuel tank pressure sensor is installed in a rubber grommet in the evaporative loss flange. The sensor provides a vapor pressure signal to the ECM.





Canister Close Valve and Filter
A canister close valve and filter assembly is installed on a bracket attached to the underside of the vehicle, above the right axle shaft. The canister close valve is a normally open solenoid valve connected to the atmospheric side of the second carbon canister. Operation of the valve is controlled by the ECM.
A hose connects the atmospheric side of the canister close valve to the filter. The filter; a nonservice item, prevents contamination of the valve during inward venting.