Jaguar Repair: fuel leak, charcoal canister, psi pressure

Question
1983 when I open the right fuel cover the gas sprays out and goes every where what can I do?

Answer
Hi Lilas,
The series III XJ-6 with two tanks has a fuel return system that is operated by the dash switch that reads each tank level and switches the tanks supply and return.

When the system fails electrically, you can be running off of the left normally. but when a valve sticks open or closed the excess return fuel can be pumped back to the wrong tank instead of the tank being used. This can overfill the opposite tank until it is full, then start pumping fuel up into the charcoal canister behind the right head light. Thus destroying the canister. And since the canister pressure valve is set at about 3 PSI which keeps that 3 PSI pressure in the both tanks and if the overfilled tank is opened, it will force fuel out of that tank.

Most likely the right tank return valve is stuck in the "OPEN" position. Or the tank switching valve has failed when using the right tank. In the event any one of the three valves fail electrically, it will default to the left tank operating normally as the two return valves and the fuel switching valve are all turned off when using the left tank.

The return valves are positioned at the bottom of each rear wheel well under a removable panel. Don't forget to test the fuel switching valve in the trunk since a failure of that valve can cause fuel to be removed from the left tank when operating on the right tank and the return fuel will be pumped into the right tank and over filling it. You MUST check the charcoal canister behind the right head light, if saturated with fuel it MUST be replaced.
Howard