The FAST EZ-EFI fuel-injection system is a self-tuning kit designed for ease of installation and performance, making it an ideal option for DIY enthusiasts and restorers. The system is configured to fit in place of traditional square-bore carburetors and is suitable for engines up to 500 cubic inches producing up to 600 horsepower. This article provides a detailed explanation of the installation process, key components, and considerations for users looking to retrofit their classic or modified engines with the FAST EZ-EFI system.
Overview of the FAST EZ-EFI System
The FAST EZ-EFI system is a complete fuel-injection retrofit kit that includes a compact throttle-body, fuel injectors, and self-tuning electronics. It mimics the appearance and functionality of a 4150-type four-barrel carburetor, making it a versatile option for a wide range of applications. The throttle body is constructed from cast aluminum and contains four proprietary fuel injectors capable of delivering up to 88 pounds of fuel per hour at 60 psi. The system also includes manifold absolute pressure (MAP), air temperature, and throttle position sensors, as well as an idle control motor.
One of the standout features of the EZ-EFI system is its self-tuning capability. The system utilizes a wide-band oxygen sensor to monitor and adjust the air-fuel mixture in real time, ensuring optimal performance without the need for extensive tuning knowledge or a laptop. This makes it an attractive option for hobbyists and restorers who may not have access to professional tuning equipment.
The system is covered by a limited lifetime warranty, and FAST leverages widely available General Motors components, which are known for their reliability and accessibility. The kit is priced at around $2,200 and includes all necessary components for installation, including fuel delivery components and an inline electric fuel pump.
Installation Considerations and Components
Before beginning the installation, it is important to understand the components included in the kit and how they integrate into the existing engine setup. The kit includes a throttle-body fuel injection unit, fuel injectors, an inline electric fuel pump, fuel rails, a fuel-pressure regulator, and necessary wiring and sensors. Additionally, users may need to acquire specific fittings or brackets depending on the application, especially if modifications are required for clearance or routing.
The installation process is estimated to take several hours when using the supplied components, and the average hobbyist should be able to complete the task over the course of a few nights in a home garage or over a weekend. The following sections outline the key steps and considerations for a successful installation.
Fuel System Modifications
The fuel system requires careful planning and modification to ensure proper function and avoid vapor lock, especially in hot climates. The FAST EZ-EFI system can be configured as either a return or returnless system, depending on the application. Return systems require more plumbing but are less prone to vapor lock, making them the preferred option for many installations.
The fuel-pressure regulator supplied with the EZ-EFI kit uses a combination of mechanical spring pressure and vacuum assistance to maintain a setting of 43 psi. It is recommended to mount the regulator after the throttle body to ensure consistent fuel pressure and volume to the injectors. In the example provided, a custom bracket was fabricated to mount the regulator on the passenger-side cylinder head for easy access.
The fuel rails are part of a pass-through design, allowing either the front or rear rail to serve as the supply or return. In the installation example, the rear fuel rail was connected to the throttle body via a 38-inch supply line with a short rubber hose for connection to the main supply line. The front fuel rail was connected to the regulator with another short rubber hose, and the regulator was then connected to the main return line.
If using the supplied hose rather than modifying the existing fuel lines, the installation can be significantly simplified. However, fuel line modifications can add several hours to the installation process and may be necessary for optimal performance.
Throttle Body and Throttle Linkage
The EZ-EFI throttle body is designed to fit in place of a traditional square-bore carburetor and is compatible with most Edelbrock Performer RPM intake manifolds. It features four 1.75-inch-diameter throttle blades, delivering more than 1,000 cubic feet per minute (cfm) at 20.4 inches of water pressure. This is significantly higher than a carburetor with similarly sized bores due to the absence of fuel-feeding booster rings, which can restrict airflow.
The throttle bracket supplied with the kit is noted for its ease of installation and is considered one of the best options for retrofitting older carburetor linkages. Proper planning is essential, as some components may require 90-degree fittings for clearance. The kit includes a variety of fittings, and users should ensure they are using the correct orientation and routing to avoid interference with other components.
Electrical and Ignition System Integration
The installation process also includes integrating the EZ-EFI system with the vehicle's electrical and ignition systems. The system requires a connection to the ignition points signal, which is typically sourced from the ignition box. This is a critical step that should not be overlooked, as skipping this connection can prevent the system from functioning properly.
In one installation example, a failure to connect this wire initially prevented the engine from starting. After contacting FAST Technical Support and checking all connections, the issue was resolved, and the engine started and ran smoothly with the out-of-the-box tune.
The ignition control system is mounted in place of the old ignition box, and a custom bracket may be required for proper installation. The new coil, which is not a conventional round unit, may also require a fabricated bracket for secure mounting on the intake manifold.
The instructions provided with the kit guide users through the process of teaching the ECU how to operate the engine through driving or dyno testing. In some cases, professional dyno tuning can yield better results, especially for engines with unique specifications or performance goals.
Performance and Benefits
The performance gains from the FAST EZ-EFI system can be significant, particularly in terms of horsepower, torque, and fuel efficiency. In one example, the system provided a gain of 26 horsepower and over 35 lb-ft of torque at 3,800 rpm compared to the original carburetor setup. The improvement in fuel efficiency was also notable, with users reporting better gas mileage and a more responsive engine.
The system's self-tuning capabilities ensure that the air-fuel mixture is continuously adjusted to optimize performance under varying operating conditions. This eliminates the need for manual tuning and allows the system to adapt to changes in temperature, altitude, and load. The wide-band oxygen sensor plays a crucial role in this process, providing real-time feedback to the ECU for precise adjustments.
For users who are not familiar with fuel-injection systems, the EZ-EFI system offers a user-friendly experience with minimal setup required. The system is designed to be plug-and-play, with most adjustments handled automatically by the self-tuning software. However, users should still be prepared to spend time planning the installation, especially when it comes to routing fuel lines, selecting the correct fittings, and ensuring proper electrical connections.
Conclusion
The FAST EZ-EFI fuel-injection system is a robust and user-friendly option for hobbyists and restorers looking to upgrade their classic or modified engines. With its self-tuning capabilities, high-flow throttle body, and compatibility with a wide range of applications, the system offers a compelling alternative to traditional carburetors. The installation process, while requiring careful planning and attention to detail, is designed to be manageable for the average DIY enthusiast.
Key considerations include the choice between return and returnless fuel systems, proper routing of fuel lines, and integration with the vehicle's electrical and ignition systems. The use of the supplied components and following the manufacturer's instructions can help streamline the installation process and ensure optimal performance.
For those who are not confident in their ability to complete the installation independently, working with a professional or seeking assistance from FAST Technical Support can be invaluable. The system's performance benefits, including increased horsepower, torque, and fuel efficiency, make it a worthwhile investment for anyone looking to enhance the performance of their classic or modified engine.