Tank
Jaguar Series 3 XJ6 fuel tank switching system Page 1 of 2
There is a fuel tank switching valve in the trunk and a fuel return valve at each fuel tank. There is a separate fuel level sensor or Sender in each tank. Some testing is going to be needed to determine any problem. Start by accessing the switchover valve solenoid in the trunk near the fuel pump. Voltage tests should be done at the valve to see if it is getting the signal to switch over. When the left tank is selected, no voltage is applied to fuel solenoid circuit. When the right tank is selected, battery voltage is applied to the switchover valve circuit. If you are not getting a signal the circuit needs to be tested at the switch in the dash. Often you can see a combination of problems with the switchover valve and the L & R return valves and the fuel level senders. See attached diagram of the system below.
Fuel Change Over Valve: p/n CBC4269
Fuel Pump: p/n CBC5657
Fuel Return Valve RIGHT: p/n CBC4270
Fuel Return Valve LEFT: p/n CAC3939
continued: Jaguar Series 3 XJ6 fuel tank switching system Page 2
The twin fuel tank setup on fuel injected 1979-1987 Series III XJ6 cars is occasionally the source of problems, especially now that most of these cars are more than 20 years old. This model has a fuel tank changeover switch on the dash above the console that selects which tank is in use. If this switch does not change tanks properly, first pop the switch out to check that the 6-pin connector has not overheated and melted due to a poor connection. These connectors are not available new at this time and have to be sourced from a used harness if needed. If any corrosion is present at the connection, clean this off. The switch itself will sometimes go bad, but that is not a common problem.
The operation of the Series III fuel changeover system is a bit more complicated than it might first appear. Like almost all fuel injection systems, the fuel pump sends sufficient fuel from
There is a fuel tank switching valve in the trunk and a fuel return valve at each fuel tank. There is a separate fuel level sensor or Sender in each tank. Some testing is going to be needed to determine any problem. Start by accessing the switchover valve solenoid in the trunk near the fuel pump. Voltage tests should be done at the valve to see if it is getting the signal to switch over. When the left tank is selected, no voltage is applied to fuel solenoid circuit. When the right tank is selected, battery voltage is applied to the switchover valve circuit. If you are not getting a signal the circuit needs to be tested at the switch in the dash. Often you can see a combination of problems with the switchover valve and the L & R return valves and the fuel level senders. See attached diagram of the system below.
Fuel Change Over Valve: p/n CBC4269
Fuel Pump: p/n CBC5657
Fuel Return Valve RIGHT: p/n CBC4270
Fuel Return Valve LEFT: p/n CAC3939
continued: Jaguar Series 3 XJ6 fuel tank switching system Page 2
The twin fuel tank setup on fuel injected 1979-1987 Series III XJ6 cars is occasionally the source of problems, especially now that most of these cars are more than 20 years old. This model has a fuel tank changeover switch on the dash above the console that selects which tank is in use. If this switch does not change tanks properly, first pop the switch out to check that the 6-pin connector has not overheated and melted due to a poor connection. These connectors are not available new at this time and have to be sourced from a used harness if needed. If any corrosion is present at the connection, clean this off. The switch itself will sometimes go bad, but that is not a common problem.
The operation of the Series III fuel changeover system is a bit more complicated than it might first appear. Like almost all fuel injection systems, the fuel pump sends sufficient fuel from