🏷️ Basic Information

Make:

Mitsubishi

Model:

Eclipse

Year:

1991

Generation:

First Generation (1G)

Chassis Code:

D22A/D27A

Platform:

Mitsubishi Galant VR-4 platform (shared with Eagle Talon, Plymouth Laser)

👋 Introduction

Segment:

Compact sports coupe, competing in the affordable performance segment.

Competitors:

Nissan 240SX, Toyota Celica, Honda Prelude, Ford Probe, Mazda MX-6.

Design:

Sleek, aerodynamic styling, available in front-wheel drive (FWD) and all-wheel drive (AWD) configurations (AWD shared with Galant VR-4 platform).

Performance Options:

Naturally aspirated and turbocharged engine options, offering a balance of performance and value.

Legacy:

Marked Mitsubishi's entry into the sport compact market in North America and established a performance image for the brand, later evolving into the Eclipse GT and performance variants.

📋 Manual Details

Trim Levels:

GS, GS-X, GS Turbo (Australia), RS, GST

Regional Variants:

North America, Australia, Japan (specifics may vary by region)

Estimated Pages:

1500+

Type:

Factory Service Manual / Repair Manual Software

Language:

English

Format:

Software (likely digital PDF or proprietary program)

📖 Manual Coverage

Powertrain:

Engine mechanical, fuel system, ignition system, exhaust system, cooling system, lubrication system, engine control systems (ECU, sensors).

Drivetrain:

Manual transmission, automatic transmission, transaxle, differentials, axles, CV joints, driveshafts.

Suspension Steering:

Front suspension (MacPherson strut), rear suspension (multi-link), steering system (power steering, steering rack), wheel alignment specifications.

Brakes:

Front disc brakes (vented), rear disc brakes (solid or vented depending on model), ABS system (where applicable), brake fluid specifications, bleeding procedures.

Electrical:

12V electrical system, battery, charging system (alternator), starting system (starter motor), lighting system, wipers, horn, power accessories, fuses, relays, wiring diagrams, diagnostic trouble codes (DTCs).

HVAC:

Heating, ventilation, and air conditioning (HVAC) system components, refrigerant type, service procedures.

Body:

Exterior body panels, interior trim, doors, windows, locks, glass, bumpers, body sealing, chassis specifications.

Maintenance:

Oil changes, filter replacements, fluid checks and top-offs, spark plug replacement, belt inspection and replacement, brake pad replacement, tire rotation.

Troubleshooting:

Diagnostic flowcharts, symptom-based troubleshooting guides for common issues (e.g., starting problems, rough idle, electrical faults).

Repair:

Engine component removal and installation (e.g., cylinder head, pistons, crankshaft), transmission overhaul, brake system repair, suspension component replacement, electrical component diagnosis and replacement.

Diagnostics:

On-board diagnostics (OBD-I), sensor testing, actuator testing, multimeter usage, oscilloscope interpretation for engine and electrical systems.

Specifications Data:

Torque specifications for all fasteners, critical clearances, diagnostic values, wiring schematics, component locations.

Depth:

Comprehensive, covering everything from basic scheduled maintenance to complete engine and transmission overhauls. Detailed diagnostic procedures for advanced troubleshooting.

📊 Manual Specifications

Format:

Digital Software (likely searchable PDF or proprietary application)

Quality:

High resolution, clear diagrams and text (typical for official service manuals).

Binding:

N/A (Software format)

Type:

N/A (Software format)

Features:

Likely includes keyword search functionality for quick access to specific information.

⚙️ Engine Specifications

Engine Code Na Gs:

4G63 (SOHC, 16-valve)

Engine Code Turbo Gsx:

4G63T (DOHC, 16-valve, turbocharged)

Gs Na Displacement:

2.0 Liters (1997 cc)

Gsx Turbo Displacement:

2.0 Liters (1997 cc)

Gs Na Horsepower:

135 hp @ 6000 rpm

Gs Na Torque:

125 lb-ft @ 4500 rpm

Gsx Turbo Horsepower:

195 hp @ 6000 rpm

Gsx Turbo Torque:

203 lb-ft @ 3500 rpm

Fuel Delivery:

Multi-point Fuel Injection (MPI)

Required Fuel:

Unleaded Regular (87 octane) for NA, Premium (91+ octane) for Turbocharged models recommended.

ECU Type:

Proprietary Mitsubishi Engine Control Unit (ECU)

🔧 Transmission

Gs Transmission:

5-speed Manual Transmission

Gsx Transmission:

5-speed Manual Transmission with All-Wheel Drive (AWD)

Gs Optional Transmission:

4-speed Automatic Transmission

Gsx Optional Transmission:

4-speed Automatic Transmission with All-Wheel Drive (AWD)

AWD System:

Advanced All-Wheel Drive system with viscous coupling center differential on GSX models.

Manual Transmission Fluid:

API GL-4, SAE 75W-90 Gear Oil (refer to manual for specific part numbers).

Automatic Transmission Fluid:

Mitsubishi ATF-SP II or equivalent (refer to manual for specific part numbers).

📐 Dimensions

Length:

Approx. 170.3 inches (4325 mm)

Width:

Approx. 69.1 inches (1755 mm)

Height:

Approx. 50.0 inches (1270 mm)

Wheelbase:

Approx. 98.6 inches (2505 mm)

Curb Weight Gs FWD:

Approx. 2900 lbs (1315 kg)

Curb Weight Gsx AWD:

Approx. 3200 lbs (1451 kg)

🛡️ Safety Features

NHTSA Driver Side Frontal Impact:

Not extensively rated under modern standards, but generally considered safe for its era.

IIHS Ratings:

Not available for this model year.

Airbags:

Driver-side airbag standard on most models, passenger airbag optional or not available.

Seat Belts:

3-point front seat belts, 2-point rear seat belts.

Crumple Zones:

Designed with front and rear crumple zones for energy absorption.

ABS:

Anti-lock Braking System (ABS) available as an option on some models (e.g., GSX).

💡 Technology Features

Audio System:

Factory AM/FM stereo with cassette player, optional CD player on higher trims or aftermarket upgrades.

Speakers:

Typically 4 or 6 speakers, depending on trim level.

Cruise Control:

Available on most models.

Power Accessories:

Power windows, power door locks, and power mirrors were available options or standard on higher trims.

Headlights:

Fixed halogen headlights.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles (6,000 km) or 3 months (refer to manual for specific oil type and capacity).

Air Filter Replacement:

Every 15,000 miles (24,000 km) or as needed based on inspection.

Spark Plug Replacement:

Every 30,000 miles (48,000 km) for standard spark plugs, or as specified for platinum/iridium plugs.

Timing Belt Replacement:

Crucial for the 4G63 engine; typically every 60,000 miles (96,000 km) or 4 years. Failure can cause severe engine damage.

Engine Oil Capacity Gs FWD:

4.7 US quarts (4.4 Liters) with filter change (refer to manual for viscosity grade, e.g., 5W-30).

Engine Oil Capacity Gsx AWD:

4.7 US quarts (4.4 Liters) with filter change (refer to manual for viscosity grade, e.g., 5W-30).

Coolant Capacity:

Approx. 7.0 US quarts (6.6 Liters) with heater (refer to manual for coolant type).

Brake Fluid:

DOT 3 or DOT 4 (refer to manual for specific recommendation).

Turbocharger System:

Potential for turbo seal failure, wastegate issues, and intercooler leaks, especially on high-mileage or modified vehicles. Regular oil changes are critical.

Suspension Components:

Wear in control arm bushings, ball joints, and tie rod ends can lead to alignment issues and premature tire wear.

Electrical Gremlins:

Can include issues with power windows, door locks, and dashboard illumination due to aging wiring and connectors.

Rust And Corrosion:

Common in areas exposed to road salt; check wheel wells, rocker panels, and underbody.

Cooling System:

Radiator leaks, hose degradation, and water pump failure can lead to overheating.

📚 Vehicle History

Mitsubishi History:

Mitsubishi Motors Corporation, a Japanese automotive manufacturer with a history dating back to 1917 (as part of Mitsubishi Group).

Eclipse Debut:

Launched in 1989 for the 1990 model year as a replacement for the Mitsubishi Cordia, marking a significant shift in design and performance focus.

Manufacturing Location:

Normal, Illinois, USA (Diamond-Star Motors plant, a joint venture with Chrysler).

First Generation Years:

1990-1994.

Initial Reception:

Well-received for its styling, performance, and value proposition, especially the turbocharged AWD GSX model.

🏆 Awards & Recognition

Automotive News:

Often cited in automotive press of the era as a strong value in the sports coupe segment. Specific awards are less documented than modern vehicles.

Car And Driver:

Frequently appeared on Car and Driver's 'Ten Best' lists in various categories during its production run for performance and value.

Emissions Standards:

Designed to meet US emissions standards for 1991.