The Evolution Of Landcruiser: Fuel Injection Transition

The Toyota Land Cruiser has been in production for over 40 years, and until 1993, the F series engines were used. These are inline-six engines with a displacement of around four liters. Initially, these engines were carbureted, but in the late '80s, Toyota introduced electronic fuel injection to the 2F engine, creating the 3FE version. This change offered several benefits, including constant fuel delivery, easy starting, smooth cold-weather performance, improved fuel mileage, and reliability.

The first Land Cruiser to feature factory fuel injection was the '87 wagon with the 3F-E engine. However, this model had lower torque due to the engine being de-stroked for higher RPMs and highway use.

Today, modern fuel injection kits are available for older Land Cruisers, offering improved performance, drivability, and fuel efficiency while also addressing the challenges of hard starting and lagging acceleration associated with aging carburetors.

Fuel injection conversion kits

The two most popular EFI kits for the 2F engine are the Howell TBI system and the Holley Sniper self-learning EFI system. The Howell TBI system utilises a GM TBI unit, with parts readily available at most auto parts stores. This system is designed for a straightforward installation, requiring only a few additional sensors, a high-pressure fuel pump, and a new wiring harness and computer.

The Holley Sniper EFI system, on the other hand, is a self-contained, self-learning system that is also easy to install. It features a fast, modern ECU located on the throttle body, and it constantly optimises fuel mapping based on the engine's performance.

Both systems offer advantages, and the choice between them depends on specific needs and preferences.

For Land Cruiser models from 1968 to 1987, the Howell TBI Conversion Kit is a suitable option. This kit converts the standard carburetor to fuel injection, improving cold starts, gas mileage, and overall drivability. It includes a GM Throttle Body, Toyota Intake Manifold Adapter Plate, Wiring Harness, MAP Sensor, Coolant Sensor, Oxygen Sensor, External Fuel Pump, and other necessary components.

For those seeking to retain their carbureted engines, Weber Conversion Kits are also available.

When considering a fuel injection conversion, it is important to carefully review the installation instructions and consult with specialists to ensure a proper setup.

Additionally, it is worth noting that some Land Cruiser models, such as the FJ60, FJ62, and FJ80, underwent changes in the late '80s, including the incorporation of electronic fuel injection, resulting in improved performance and fuel efficiency.

Pros and cons of the Howell and Holley Sniper systems

The Toyota Land Cruiser first introduced fuel injection in the late 1980s, with the release of the 3FE engine. This new engine featured a new intake and exhaust manifold and the incorporation of electronic fuel injection.

Now, here's a comparison of the Howell and Holley Sniper systems:

Howell TBI System

The Howell TBI (Throttle Body Injection) system is a popular option for those seeking a more modern fuel injection system. Here are some pros and cons of the Howell TBI:

Pros:

• The Howell TBI system is a complete replacement for fuel and spark management, providing a mapped system that matches a specific engine profile.
• It is a good choice for those with a stock 4.2 motor, as it is designed to work with the stock ignition system.
• The Howell TBI is legal in California, making it a good option for those in emission-controlled counties or states.
• It is a refurbished GMC unit from 1989, so it may be a good choice for those seeking a classic or vintage option.

Cons:

• The Howell TBI does not offer the same level of tunability as the Holley Sniper, making it less suitable for modified engines or those seeking customisation.
• As a 30-year-old refurbished technology, it may be less reliable and more prone to issues than a newer system.
• The Howell TBI is a proprietary system, so repairs and replacements may be more challenging and require specialised parts.

Holley Sniper EFI System

The Holley Sniper EFI (Electronic Fuel Injection) system is a modern and feature-rich option. Here are some pros and cons of the Holley Sniper EFI:

Pros:

• The Holley Sniper EFI offers a huge step up from a carburettor, providing modern features like electronic fuel management and improved performance.
• It has a sleek and simple installation process, with the ECU and other components integrated into the throttle body.
• The Holley Sniper EFI provides a high level of tunability, making it ideal for those with modified engines or specific performance requirements.
• The system includes a self-tuning feature and a wide-band O2 sensor, allowing it to adapt to different engine configurations.
• The Holley Sniper EFI has a robust community forum support, with users sharing their experiences, tunes, and solutions to common issues.

Cons:

• The Holley Sniper EFI is more expensive than the Howell TBI, with a price difference of around $900 for a complete kit.
• It requires more fiddling and tuning than the Howell TBI, especially for those new to EFI systems or without a background in engine tuning.
• Some users have reported issues with the Holley Sniper EFI, including problems with datalogging and unexpected behaviour. However, these issues may be due to user error or a lack of understanding of the system.

In conclusion, both the Howell TBI and Holley Sniper EFI systems offer significant advantages over carburettors. The Howell TBI is a good choice for those seeking a simple, emission-legal solution, especially for stock engines. On the other hand, the Holley Sniper EFI provides advanced features, tunability, and modern technology, making it ideal for those seeking customisation and improved performance.

The carburettor vs fuel injection debate

The carburettor versus fuel injection debate has been ongoing for years, with enthusiasts on both sides extolling the virtues of their preferred system. While carburettors have long been the standard for fuelling engines, the advent of fuel injection technology has sparked a discussion about which system is superior. This debate is particularly relevant when discussing the evolution of the Land Cruiser, which transitioned from carburettor to fuel injection over its production history.

Carburettor vs. Fuel Injection: The Basics

At its core, the debate centres around two different methods of delivering fuel to an engine. A carburettor is a mechanical device that mixes air and fuel before supplying it to the engine. It relies on the suction created by air passing through a narrow tube (venturi) to draw fuel from a jet, resulting in a combustible mixture. Carburettors are simple, cost-effective, and allow for customisation to meet specific requirements.

Fuel injection, on the other hand, is a more modern approach that utilises electronic sensors and components to deliver fuel directly to the combustion chamber. This system is controlled by an Electronic Control Unit (ECU), which calculates and delivers the precise amount of fuel needed based on various parameters such as engine speed, throttle position, and temperature. Fuel injection offers improved fuel efficiency, cleaner combustion, and sharper throttle response.

Advantages and Disadvantages

Proponents of carburettors appreciate their low cost, simplicity of operation, and ease of repair or replacement. Carburettors provide users with the flexibility to tune them according to their power and mileage requirements. Additionally, since carburettors are separate from the engine, they can be serviced or replaced without affecting the engine itself.

However, carburettors have their drawbacks. They are not the most efficient systems and their design is considered dated. Carburettors often exhibit lag, resulting in slower throttle response. Certain components, such as the diaphragm, are delicate and prone to damage. The air-fuel mixture in carburettors can fluctuate, affecting engine smoothness.

Fuel injection systems offer several advantages over carburettors. They provide optimised air-fuel mixture and atomisation, resulting in cleaner and more efficient combustion. Fuel injection delivers sharper throttle response, better fuel efficiency, and marginally more power. These systems are also known for their low maintenance requirements and reliability.

Despite these advantages, fuel injection is not without its drawbacks. It is substantially more expensive than carburettors, and repairs or customisations can be costly. The complexity of fuel injection systems may deter those who prefer the simplicity of carburettors. Additionally, if the ECU fails, the vehicle may be left stranded.

The Land Cruiser's Evolution

The Toyota Land Cruiser is a notable example of the transition from carburettor to fuel injection. Early models, such as the FJ40 and FJ55, were equipped with carburetted F and 2F engines. In the late 1980s, Toyota introduced the 3FE engine, which featured electronic fuel injection and a new intake and exhaust manifold. This marked a significant upgrade in terms of performance and fuel efficiency.

The adoption of fuel injection in the Land Cruiser addressed several issues associated with carburettors, such as poor fuel mileage and carburettor stumbling during off-road use. The fuel injection system provided improved throttle response, easier starting, and smoother engine performance, even in cold conditions. Additionally, fuel injection eliminated issues with vapor lock and improved reliability.

The carburettor versus fuel injection debate continues to divide enthusiasts, with each side highlighting the strengths of their preferred system. While carburettors offer simplicity, customisability, and low cost, fuel injection provides improved performance, fuel efficiency, and reliability. The evolution of the Land Cruiser illustrates the industry's shift towards fuel injection, prioritising emission standards and improved engine performance. Ultimately, the choice between carburettor and fuel injection depends on specific requirements, with each system offering unique advantages and trade-offs.

The merits of fuel injection

Fuel injection systems have been used in compression-ignition engines (e.g. diesel engines) and spark-ignition engines (i.e. petrol engines) since the 1930s and 1950s, respectively. The primary difference between carburetion and fuel injection is that the latter atomises fuel through a small nozzle under high pressure, while the former relies on suction created by intake air accelerated through a Venturi tube to draw fuel into the airstream.

Constant Fuel Delivery

No matter the angle of the vehicle, fuel injection ensures a constant supply of fuel to the engine. This is in contrast to carburettors, which can experience fuel starvation when the vehicle is tilted or upside down.

Easy Starting and Smooth Running

Fuel injection systems enable easy starting of the engine, even when it is cold. This is because the fuel injectors deliver the right amount of fuel directly into the cylinders, ensuring a consistent air-fuel mixture. Carburettors, on the other hand, rely on suction to draw fuel into the airstream, which can be less reliable, especially in cold weather.

Improved Gas Mileage

By delivering the precise amount of fuel required, fuel injection systems can improve fuel economy. Additionally, removing carbon deposits during fuel injection services can restore balanced air and fuel flow, further enhancing fuel efficiency.

Better Atomisation and Vaporisation

Fuel injection systems atomise and vapourise fuel more effectively, resulting in less knocking and improved engine performance. This is because the atomisation of fuel is independent of the cranking speed, leading to good atomisation even at low speeds.

Reliability

Fuel injection systems are known for their reliability due to the elimination of issues such as manifold wetting, vapor lock, and ice formation at the throttle plate. They also have a wider range of usable fuels as the distribution of fuel is independent of vaporisation.

Reduced Emissions

Fuel injection services remove toxic contaminants from the engine, resulting in significantly reduced emissions. This not only benefits the environment but also helps ensure that your vehicle meets emissions standards.

Injector replacement

When to Replace Fuel Injectors

You should consider replacing your fuel injectors if you experience any of the following issues:

• Rough idle, loss of power, or misfiring
• Odor of raw gas or visible leaks around your car
• Check engine light is illuminated due to a faulty solenoid or other fuel injection failures
• Major engine repairs, engine replacement, or lengthy storage of your vehicle

The Replacement Procedure

The following is a general overview of the fuel injector replacement procedure, which may vary depending on your vehicle's specific model and year:

• Relieve the pressure within the fuel rail by briefly running the engine with the fuel pump fuse removed.
• Remove the upper plenum on the intake manifold, along with any cables, hoses, or wiring that restricts access.
• Disconnect the supply and return lines from the fuel rail and the electrical connectors from each fuel injector. Then, unbolt and remove the fuel rail from the intake manifold.
• Carefully remove the injector(s) requiring replacement from the fuel rail, being cautious not to allow any debris to enter the exposed openings.
• Insert the serviced or replaced injector(s) into the fuel rail, using a new O-ring and engine oil to prevent damage.
• Reinstall the fuel rail, reconnect the supply and return lines, and reattach the plenum along with all cables, hoses, or wiring.
• Run the engine and perform a careful check for leaks. Finally, road test your vehicle.

Additional Considerations

• It is generally recommended to service or replace all fuel injectors at the same time to ensure a balanced performance.
• Using high-quality (Tier One) gasoline may help reduce deposits on fuel injectors and prolong their lifespan.
• Do not use fuel system cleaning compounds or procedures unless specified by the manufacturer of your vehicle.
• On-car cleaning of fuel injectors may not be as effective as off-car cleaning due to the presence of tiny internal filter baskets that should be replaced during the service.

Frequently asked questions