Positioning:
The 1990 Jaguar XJS was positioned as a refined and luxurious grand tourer, offering a blend of performance, comfort, and distinctive British style, competing with vehicles from marques like Mercedes-Benz and BMW in its segment.
Competitors:
Key competitors included the Mercedes-Benz SL-Class, BMW 8 Series, and the Porsche 928. The XJS differentiated itself with its classic Jaguar styling and emphasis on comfortable, high-speed cruising.
Defining Attributes:
Long, low-slung profile, powerful V12 or inline-six engines, plush interior, and excellent long-distance touring capability.
Engine Mechanical:
Detailed procedures for all engine variants, including disassembly, assembly, diagnostics, and component replacement.
Fuel System:
Includes fuel injection system diagnostics, pump replacement, injector testing, and fuel line maintenance.
Ignition System:
Covers ignition timing, distributor, coil packs, spark plug replacement, and electronic control unit (ECU) diagnostics.
Cooling System:
Radiator, water pump, thermostat, cooling fan operation, and coolant flush procedures.
Exhaust System:
Catalytic converter, muffler, exhaust manifold, and emissions control system details.
Transmission Automatic:
Diagnostics, fluid changes, seal replacements, and internal component repair for the automatic transmission.
Drivetrain:
Propeller shaft, driveshafts, U-joints, and differential maintenance and repair.
Suspension:
Front and rear suspension component replacement (wishbones, shock absorbers, bushings), alignment procedures, and troubleshooting.
Steering:
Power steering system diagnosis, pump and rack replacement, and steering column adjustments.
Brakes:
Front and rear brake system overhauls, caliper replacement, rotor resurfacing/replacement, brake fluid bleeding, and ABS diagnostics.
Electrical System:
Comprehensive coverage of the vehicle's electrical system, including battery, alternator, starter, lighting, and accessory circuits.
Wiring Schematics:
Detailed, high-resolution wiring diagrams for all vehicle systems, essential for troubleshooting electrical faults.
Bodywork And Interior:
Panel replacement, door mechanism repair, trim removal, seat adjustments, and body panel alignment.
Climate Control:
HVAC system diagnosis, refrigerant charging, blower motor, compressor, and heater core replacement.
Dashboard And Instruments:
Instrument cluster removal and repair, gauge diagnostics, and warning light troubleshooting.
Routine Maintenance:
Oil and filter changes, air filter replacement, spark plug inspection/replacement, coolant checks, and fluid top-offs.
Troubleshooting Guides:
Systematic diagnostic procedures for common and uncommon faults, with symptom-based troubleshooting trees.
Component Replacement:
Step-by-step instructions for replacing individual components within all major systems.
Rebuilding Procedures:
Detailed instructions for the overhaul and rebuilding of major mechanical components like engines and transmissions.
Diagnostic Techniques:
Guidance on using diagnostic tools and techniques specific to the Jaguar XJS of this era.
Depth:
Comprehensive, suitable for professional mechanics and experienced DIY enthusiasts. Covers detailed diagnostics, component-level repair, and complete overhauls.
Engine Options:
4.0L (3980cc) Jaguar AJ6 Inline-6 and 5.3L (5343cc) Jaguar V12
Inline 6 Horsepower:
Approx. 223 hp @ 4750 rpm (for the 4.0L AJ6)
Inline 6 Torque:
Approx. 277 lb-ft @ 3800 rpm (for the 4.0L AJ6)
V12 Horsepower:
Approx. 263 hp @ 5000 rpm (for the 5.3L V12, depending on market/emission controls)
V12 Torque:
Approx. 304 lb-ft @ 3750 rpm (for the 5.3L V12)
Fuel Delivery:
Bosch L-Jetronic or Lucas electronic fuel injection for both engine variants.
ECU Type:
ECU controlled engine management for ignition and fuel injection.
Oil Change:
Typically every 5,000-7,500 miles or 6-12 months, depending on driving conditions and oil type used.
Transmission Fluid:
Recommended fluid change every 30,000-60,000 miles, though checking the manual for the specific ZF transmission fluid is crucial.
Engine Oil:
API SG or SH, SAE 10W-40 or 20W-50 recommended (refer to manual for precise grade based on climate).
Coolant:
Ethylene glycol-based, 50/50 mix with distilled water. Specific Jaguar coolant recommendation is ideal.
Brake Fluid:
DOT 3 or DOT 4.
Power Steering Fluid:
Typically Dexron II or equivalent ATF.
Electrical Gremlins:
Age-related electrical issues are common; wiring harness degradation, connector corrosion, and faulty relays.
Cooling System:
Potential for radiator leaks, hose deterioration, and water pump failures.
Suspension Bushings:
Wear in rubber bushings leading to handling degradation and knocking noises.
Fuel Injectors:
Clogging or failure of fuel injectors, particularly on higher mileage vehicles.
Rust And Corrosion:
Common areas include wheel arches, sills, and underbody, especially in regions with salt usage.