The Series III XJ6 and the XJS both have a reputation for being "easily combustible." The typical cause of engine fires is a leaking or ruptured fuel injector hose or fuel supply line. On the Series III, there are two places that you’ll want to check periodically. The first place is the fuel injector hose attached to each injector. These short hoses are held on with fuel injector clamps (not hose clamps.) The clamps can loosen over time, allowing fuel to start leaking past the clamp. Check these clamps every few months to make sure they are tight. The second place to check is the fuel supply line to the fuel rail. Sometimes this line can chafe against the battery, and wear a thin spot in the hose. Check it every few months, and reroute it if possible to get it away from the battery case.
The XJS also has two common fire culprits. The first is the short fuel lines supplying each injector. The intense engine heat and the ozone from the spark plug wires make these lines hard and brittle, and easily ruptured. If you can’t squeeze them with your fingers (with the engine off, please,) or if they have any cracks evident, then they are too hard and need to be replaced
The second fire culprit is the cap and rotor on the Marelli ignition system. The Marelli ignition system was installed in the middle of the ’89 model year, and is distinguished by the TWO coil wires going into the distributor cap, rather than just one. If you have a Marelli ignition, only use the factory cap and rotor, even though they are more expensive than the aftermarket parts. The aftermarket parts are of significantly inferior quality, and can’t handle the electrical current. These parts will eventually burn through and cause an engine fire that will cause so much damage that the insurance company will probably total your car, even if the fire is restricted to the top of the engine. Check your owner’s manual, and replace the cap and rotor according to Jaguar’s mileage recommendations. Marelli fires are legendary, and legendarily expensive to repair.
See our Jaguar Parts Store Catalog to order parts.