Today, there are more choices than you can shake a stick at when it comes to classic car modifications. The hot rod and musclecar industry is alive and kicking with performance parts, upgrades, and add-ons. Just about anything you might want do to your car is waiting on a shelf for you to snag it up and slap it on.
One modification gaining in popularity the past few years is the EFI conversion. What used to mean hours and hours at a wrecking yard buying a few components at a time, has been made simple with the introduction of a complete, bolt-on kit to convert a carburetor to fuel injection. We’re going to follow through with Ken Ferrell and Quick Fuel Technology(QFT) as he shows us how simple it is to convert his own 1972 Plymouth Barracuda to fuel injection with the Quick Fuel Injection (QFI) Master Kit.
Quick Fuel Technology is well known for their performance carburetors and fuel system technology since their inception in 1998. Since then, they’ve released street and race carburetor lines that have been designed around performance and technology. Keeping on the forefront with carburetor main body designs and innovations, it’s no surprise that Quick Fuel Technology has entered into the EFI arena with their new QFI system.
Ferrell’s sublime E-body sees lots of street and track time, as well as a few local cars shows we’ve attended lately, so fuel economy in a classic musclecar could definitely use some attention – this car gets driven. As Ferrell explains, the system will replace the carburetor on most any V8 engine with 250 to 525 crank horsepower.
The QFI kit is available with a polished aluminum throttle body or what QFT calls “black diamond.” The kit is complete, with nothing more to purchase to convert a standard, 4150-flange intake manifold from carburetion to fuel injection.
The base kit from QFT includes the throttle body, ECU, harness, handheld controller, temperature and wideband O2 sensor, fuel inlet kit, and a DVD software and installation disc. The master kit being installed in the video above adds the fuel hose and fittings, fuel pump and filter, and the fuel pressure regulator and gauge to the base kit for a complete installation.
Planning And Beginning The Installation
The QFI system is a self-learning fuel injection conversion with adaptive-learning technology. Once installed, it continues to learn and make necessary adjustments to keep the engine running smoother and more efficiently.
The multiple sensors and included harness are all a part of the integral unit that makes the QFI function properly and to continue to process readings from the wideband O2 sensor included in the kit.
There is also a separate coolant temperature sender that needs to be installed in the intake manifold for the ECU. This should not be confused with the sender for the gauge, as it is specific to the QFI and must be used in order for accurate coolant temperature readings.
Planning out the installation should be the first order of business; the new fuel hose needs to be routed, the pressure regulator needs to be mounted somewhere accessible, and the ECU will need to be accessible, too.
After disconnecting the battery, the throttle body bolts on in place of the carburetor, and has an identical throttle control as a carburetor, making throttle connection simple. The four 66 lb/hr injectors are mounted to the throttle body, as well as the idle air control (IAC), throttle position sensor (TPS), manifold absolute pressure sensor (MAP), and the air temperature sensor. The harness for the injectors and sensors is attached to the throttle body for simple hook up to the ECU wiring harness with a simple plug-in connection.
The throttle body includes ports for vacuum and positive crankcase ventilation (PCV) on the main body, with the injectors at each corner, fore and aft. Ferrell said, “The throttle body itself features annular discharge booster and a special idle transition slot for better fuel atomization and distribution.” This puts the fuel and air together inside the throttle body, but helps to atomize the fuel rather than just squirting fuel into the base of the intake manifold like a carburetor does.
Ferrell recommends replacing the gasket with the new one provided in the kit, and connecting all hoses and linkages prior to moving on to the next phase of the installation. The included instructions are easy to follow, and this installation should take about a day for someone with moderate mechanical skills. It requires a bit of knowledge, more than just bolting on a carburetor, but understanding fuel systems and electrical connections is recommended. The novice can complete this installation following the instructions, so it shouldn’t discourage you from trying.
The throttle body itself features annular discharge booster and a special patented idle transition slot for better fuel atomization and distribution. -Ken Ferrell
As mentioned, the ECU needs to be accessible, and Ferrell mounted it in the cabin. The harness for the handheld is long enough to reach to the driver’s seat, but if the ECU is mounted in the engine compartment it can make setup a little more difficult. In addition to running the electrical harness into the cabin, an additional vacuum line also needs to be connected to the ECU, Ferrell recommends that new vacuum hoses are used to assure a proper connection.
The ECU is the brains of the system, but the wideband O2 sensor is the instigator. A standard, narrowband O2 sensor reads the air/fuel ratio (AFR) and only reports to the computer if the AFR is rich or lean. The five-wire wideband O2 sensor is more precise and tells the computer how rich or how lean the system is, and helps the self-learning QFI system to make finer adjustments to the fuel delivery.
To mount the O2 sensor, QFT has included a stainless steel bung that can be clamped or welded to the exhaust pipe. This makes it convenient to install the system and have the bung welded later at an exhaust shop if so desired. The bung is mounted to the pipe after drilling a hole and clamping it to the pipe with the supplied gasket and worm-gear clamps.
Fuel System, Electrical, and Setup
The QFI requires a return-style fuel system, and a vented fuel tank is also required. The instruction booklet explains how to achieve this with a stock tank; for this installation a custom tank was used with the necessary connections. The included fuel pump is an in-line pump designed to be installed low on the frame rail, and should be lower than the fuel tank if possible.
The included fuel filter is also attached low on the frame rail, after the pump, with care being taken to mount it for fuel to flow in the direction of the arrow on the filter housing. The hose connections between tank, pump, and filter are made, then the electrical harness is connected to the pump for power, with a ground connection added to any solid spot on the frame or chassis. The fuel lines are then connected to the regulator, leaving the final phase of the installation: the electrical wiring.
The wires are all color coded on the harness for simple connection and installation. The main power wire needs to be connected directly to the positive battery terminal, and should never be connected to a circuit that is shared by another component. The trigger wire for the QFI system should be connected to an ignition wire that is hot during both crank and run conditions.
After the wiring has all been connected and terminated properly, the battery can be reconnected. Ferrell recommends that the hot wire to the battery is connected first, then the ground. The setup is a simple process that starts with plugging in the handheld and going through a series of questions about the engine, such as cylinders, cam type, distributor type, fan control, fuel pump settings and more.
The QFI offers four different ignition timing control options, including HEI and ready-to-run distributors, or standard ignitions with or without an aftermarket CDI ignition box. The setup on the handheld will prompt for each series of questions and will request that the car is started to finalize the setup. Before cranking the ignition over, Ferrell recommends turning the key to ‘on’ and checking all fuel hose connections for leaks prior to firing it up. Once the system has been inspected, the car can be started and continue to follow the on-screen instructions for finalizing the setup.
The system needs to learn, so once the proper engine temperature has been reached, and the idle has been adjusted, the final process for installation is to drive the car and allow the computer to learn from the system. The handheld is all that is needed for basic QFI system installation, however, for those who possess more advanced tuning abilities, the included DVD will have further tuning instructions when a laptop is connected to the ECU.
The Quick Fuel Injection from Quick Fuel Technology is an adaptive, self-learning system that will continue to learn and make adjustments to the ECU without further input from the operator. Better starting, smoother idle, better performance, and increased fuel economy are all benefits from the QFI – all features that you’ll feel in the seat of your pants – especially if that’s where you keep your wallet.
For more information about the QFI electronic fuel injection conversion kit, and other Quick Fuel Technology performance components, be sure to check out their website or their Facebook page. It’s all about drivability, and the QFI makes putting your musclecar back on the road more fun, and more affordable with reliable EFI.