Most common types of electronic fuel injection (EFI) conversion kits rely on a single throttle body to deliver fuel into the intake manifold—very much like a traditional carburetor.

But a lot of modern engines use something called multi-port fuel injection (MPFI) in which multiple injectors are used, often placed further downstream in the manifold, directly ahead of the intake valve.

That’s because MPFI systems produce better fuel atomization and distribution than a conventional throttle body-injection system, resulting in improved performance and efficiency.

Which is why Edelbrock’s Pro-Flo 4 EFI Systems caught our attention.

The Pro-Flo 4 uses a carbureted-style intake manifold and throttle body like most aftermarket EFI systems do, but it’s actually an MPFI system—complete with fuel rails and eight injectors mounted on the manifold.

Fuel delivery is timed with the intake valve opening and delivered into the airflow stream right before it enters the combustion chamber. The throttle body is for air delivery only.


Instead of feeding the fuel into the throttle body, the Pro-Flo 4 system delivers it to individual injectors housed in the intake manifold. (Image/Summit Racing)

The Pro-Flo 4’s self-learning ECU features a faster processor and an upgraded Bluetooth chip that is faster, more reliable and will not drop connection.

It’s easy to use thanks to Edelbrock’s free E-Tuner app that connects to the ECU via Bluetooth. That allows you to adjust air-fuel ratios, ignition curve, idle speed, acceleration fuel, cooling fans, rev limiter, and other parameters using an Android-based smartphone or tablet.

The E-Tuner comes with dyno-tested baseline calibrations and an easy-to-use setup wizard to get you started.

You can get your Pro-Flo 4 system with or without a tablet with the E-Tuner app already installed.

The Edelbrock Pro-Flo 4 comes with these components:

• Fully assembled intake manifold with air valve, fuel rails, and injectors
• Fully assembled, OEM high-quality wiring harness with pre-terminated connectors and labeled connections
• Wideband oxygen sensor
• Distributor
• Gaskets and hardware

You also have a choice of Edelbrock fuel systems to feed your Pro-Flo 4:

• Return-style fuel systems are ideal for any vehicle where you can mount the fuel pump in a location lower than the fuel tank. They can handle higher-horsepower engines and come with a fuel pressure regulator so you can adjust fuel pressure for optimum performance.

• The sump-style fuel system doesn’t require running a return fuel line back to the tank. It works with your existing mechanical or electric fuel pump and can support up to 600 horsepower.

You can get Pro-Flow 4 systems for a lot of popular applications, including GM LS, small/big block Chevy, Ford Windsor, Ford 390-228 FE, Pontiac 326-455, and small/big block RB Chrysler.

Author: Alan Rebescher

Editor, author, PR man—Alan Rebescher has done it all in a 25 year career in the high performance industry. He has written and photographed many feature stories and tech articles for Summit Racing and various magazines including Hot Rod, Car Craft, and Popular Hot Rodding, and edited Summit Racing’s Street & Strip magazine in the 1990s. His garage is currently occupied by a a 1996 Mustang GT ragtop.