🏷️ Basic Information

Make:

Ford

Model:

F-150

Year:

1991

Product Type:

Repair Manual

👋 Introduction

Vehicle Segment:

Full-size pickup truck.

Target Audience:

Work trucks, fleet vehicles, personal use trucks known for durability and utility.

Primary Competitors:

Chevrolet C/K series (Silverado), Dodge Ram, GMC Sierra.

Strengths:

Robust construction, powerful engine options, capable of heavy hauling and towing, reliable powertrain.

Model Highlight:

The 1991 F-150 represents a significant evolution in Ford's light-duty truck line, building upon decades of heritage.

📋 Manual Details

Overall Scope:

Comprehensive service and repair coverage for the 1991 Ford F-150 pickup truck.

Estimated Pages:

Varies by publisher, typically 500-1500 pages for a full factory service manual.

Type:

Factory Service Manual (FSM) / Shop Manual

Language:

English

Format:

Printed physical book

📖 Manual Coverage

Engine:

4.9L I6 (300 cu in), 5.0L V8 (302 cu in), 5.8L V8 (351 cu in Windsor)

Transmission:

Manual (4-speed, 5-speed), Automatic (E4OD, AOD, C6)

Drivetrain:

Rear-Wheel Drive (RWD), Four-Wheel Drive (4WD) including transfer case and front/rear axles

Brakes:

Front disc, rear drum; Anti-lock Braking System (ABS) if equipped

Suspension:

Front Twin-I-Beam independent suspension, Rear leaf spring solid axle

Steering:

Power-assisted recirculating ball

Electrical:

Charging system (alternator), Ignition system (distributor, electronic), Starting system (starter motor), Lighting, Instrumentation, Wiper/Washer system, Power accessories

Fuel System:

Electronic Fuel Injection (EFI) for all engines

Cooling System:

Radiator, fan, water pump, thermostat, coolant types

Exhaust System:

Catalytic converter, mufflers, pipes, sensors

Body And Frame:

Body panel repair, chassis lubrication, door mechanisms, cab/bed construction

HVAC:

Heating, Ventilation, and Air Conditioning (HVAC) system diagnosis and repair

Maintenance:

Oil changes, filter replacements, fluid checks and changes, lubrication, tune-ups, brake inspection and service, tire rotation.

Diagnostics:

Troubleshooting guides, symptom-based diagnostics, diagnostic trouble codes (DTCs) for EFI systems.

Repair:

Component removal, installation, and repair for all major systems including engine, transmission, brakes, suspension, steering, and electrical.

Rebuilds:

Detailed instructions for engine and transmission overhauls and rebuilds.

Adjustments:

Valve adjustments (where applicable), idle speed, brake adjustments.

Wiring Diagrams:

Complete electrical system wiring schematics for various configurations.

Depth:

Factory-level detail, suitable for professional technicians and advanced DIY enthusiasts.

Diagnostic Tools:

Information on using diagnostic tools like Ford's EEC-IV (Electronic Engine Control) diagnostic reader.

Specifications:

Torque specifications, clearances, fluid capacities, electrical resistance values, timing specifications.

📊 Manual Specifications

Digital Format Availability:

Typically available as a printed manual; digital formats (PDF) may be sourced from third-party resellers or services.

Print Quality Typical:

Good quality paper and printing for clarity of text and diagrams in original factory manuals.

Binding Type Typical:

Hardcover or professional paperback binding.

Paper Type Typical:

Durable, often glossy paper for diagrams and photos.

⚙️ Engine Specifications

Engine 1 Displacement:

4.9 Liters (300 cubic inches)

Engine 1 Configuration:

Inline-6 (I6)

Engine 1 Fuel System:

Electronic Fuel Injection (EFI)

Engine 1 Horsepower Est:

145-150 hp

Engine 1 Torque Est:

240-255 lb-ft

Engine 2 Displacement:

5.0 Liters (302 cubic inches)

Engine 2 Configuration:

V8

Engine 2 Fuel System:

Electronic Fuel Injection (EFI)

Engine 2 Horsepower Est:

185-190 hp

Engine 2 Torque Est:

270-280 lb-ft

Engine 3 Displacement:

5.8 Liters (351 cubic inches) Windsor

Engine 3 Configuration:

V8

Engine 3 Fuel System:

Electronic Fuel Injection (EFI)

Engine 3 Horsepower Est:

200-210 hp

Engine 3 Torque Est:

300-310 lb-ft

Fuel Type:

Unleaded gasoline

Injection Type:

Sequential Electronic Fuel Injection (SEFI) for most configurations, some variations exist.

Fuel Pump Type:

In-tank electric fuel pump

🔧 Transmission

Manual Transmission Standard:

4-speed manual (e.g., NP435) on some base models.

Manual Transmission Optional:

5-speed manual (e.g., M5OD-R2) widely available.

Automatic Transmission Option 1:

AOD (Automatic Overdrive) 4-speed

Automatic Transmission Option 2:

E4OD (Electronic 4-speed Overdrive) on heavier duty models or with larger engines.

Automatic Transmission Option 3:

C6 3-speed automatic (less common on newer EFI models).

Drivetrain Options:

Rear-Wheel Drive (RWD) and Four-Wheel Drive (4WD).

Transfer Case 4Wd:

New Process (NP) 208 or BorgWarner 1345 manual shift transfer case.

📐 Dimensions

Wheelbase Options:

116.8 inches (Regular Cab Short Bed), 133.0 inches (Regular Cab Long Bed, SuperCab Short Bed), 152.5 inches (Regular Cab XLWB, SuperCab Long Bed).

Overall Length Est:

197.2 to 216.8 inches (depending on configuration).

Overall Width Est:

79.0 inches.

Overall Height Est:

74.7 inches.

Bed Length Options:

6.5 ft (short bed) and 8.0 ft (long bed).

Curb Weight Est:

Approx. 3,800 - 4,500 lbs (depending on configuration).

Gvwr Est:

5,000 - 6,000+ lbs (depending on F-250/F-350 variants if applicable).

Payload Capacity Est:

1,500 - 2,500+ lbs.

Towing Capacity Est:

Up to 7,000 - 7,500 lbs (properly equipped).

🛡️ Safety Features

NHTSA Ratings 1991:

Data for 1991 vehicles is often limited; focus on passive and active features.

ABS:

Anti-lock Braking System (ABS) available on rear wheels, optional front disc/rear drum.

Lighting:

Halogen headlamps, multi-reflector taillamps.

Seat Belts:

Lap and shoulder belts for front occupants, lap belts for rear occupants (if applicable).

Structure:

Steel frame and body construction, energy-absorbing steering column.

💡 Technology Features

Radio Options:

AM/FM stereo with cassette player, optional premium sound systems.

Speakers:

Basic speaker configurations, door speakers, dash speakers.

Cruise Control:

Optional electronic cruise control.

Power Features:

Optional power windows, power door locks, power mirrors.

OBD Ii:

Not applicable; uses older EEC-IV diagnostic connector.

🔧 Maintenance

Oil Change Interval:

Every 3,000-5,000 miles or 3-6 months (check manual for specific recommendation based on driving conditions).

Air Filter Replacement:

Every 15,000-30,000 miles or as needed based on conditions.

Spark Plugs Replacement:

Typically every 30,000-60,000 miles depending on plug type.

Coolant Flush:

Every 30,000-50,000 miles or 2-3 years.

Engine Oil:

API Service SG or SH, SAE 5W-30 or 10W-30 (consult owner's manual for temperature-specific viscosity).

Transmission Fluid Auto:

Mercon Automatic Transmission Fluid (ATF).

Transmission Fluid Manual:

API GL-4, SAE 75W-90 or 80W-90 gear oil (consult manual for specific type).

Coolant:

Permanent type ethylene glycol antifreeze (typically a 50/50 mix with distilled water).

Brake Fluid:

DOT 3.

Common Wear Items:

Ball joints, tie rod ends, leaf spring bushings, exhaust system corrosion, fuel pump failure, ignition coil issues, starter solenoid.

Electrical Issues:

Corrosion in connectors, failing voltage regulators, dashboard gauge issues.

Efi Troubleshooting:

Check for vacuum leaks, faulty O2 sensors, clogged fuel injectors, and failing EEC-IV components.

Tire Size Common:

P235/75R15, P215/75R15 (check specific trim and options).

Wheel Bolt Pattern:

5x139.7mm (6-lug for heavier duty, 5-lug for lighter duty).

📚 Vehicle History

Ford Truck Legacy:

Ford has a long and storied history in the pickup truck market, dating back to the Model T Runabout with a pickup body in 1917.

F-Series Lineage:

The F-150 is part of the F-Series line, which has been America's best-selling truck for many years. The 1991 model is part of the 9th generation (1992-1997), though often considered an evolution of the 8th gen. It introduced more aerodynamic styling and improved fuel efficiency.

Manufacturing Locations:

Primarily assembled in the United States (e.g., Wayne, Michigan; Claycomo, Missouri).

Model Year Significance:

1991 marked the final year for some of the older design elements before the major redesign of the 10th generation (1997). It was a period of refinement for the established platform.

🏆 Awards & Recognition

Ford F Series Reputation:

Ford F-Series has consistently been recognized for its durability, capability, and value, often topping sales charts in North America.

Truck Of The Year:

While specific 'Truck of the Year' awards for the 1991 model year are difficult to pinpoint retrospectively, the F-Series platform generally received strong industry reviews for its utilitarian strengths and V8 engine options.