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by FordMuscle Staff

Less than Obvious
Take a good look at the picture above. It's not a "before" picture of our engine prior to converting to electronic fuel injection. That is indeed the "after" picture. Under the stock air cleaner sits a mass air meter and four-barrel throttle body. About all that gives clues that this is an injected motor are the fuel rails and ignition module on the distributor. This is the concept behind Mass-Flo EFI's fuel injection conversion kit. Their specialty is vintage looking EFI systems which retain the classic four-barrel carburetor underhood appearance. While some enthusiasts converting classic vehicles to modern powertrains prefer the modern look, others do not. We can certain sympathize with that notion. When we set out to convert our Project '67 to EFI, I was opposed to the idea of a big square manifold with throttle body and MAF meter taking up real-estate under my hood. I've always felt that cars should visually reflect the era they represent while being as technologically modern as possible. Mass-Flo has found this line of thinking to be very prominent among

Mass-Flo's EFI systems are based off of factory EEC-IV mass air processors. Shown is an A9L computer inside Mass-Flo's convenient mounting tray.

muscle car owners, kit car builders and hot rodders. So much so that they've made these stealthy EFI systems their specialty.

The key is a modified single plane carbureted intake of your choice for fuel injectors and a GM style mass air meter which sits on top of the throttle body. The mass-air meter ends up being inside the air cleaner housing and fully concealed. The meter comes calibrated to the injector size you plan to run and the a converter box is supplied to transmit the proper voltage signal for the Ford computer. As a result the system is deemed plug and play, requiring no tuning to get up and running. Even more impressive is that Mass-Flo is now able to fuel-inject virtually any Ford engine with their custom specified TFI-module distributors for FE, Cleveland and 385 series engines (see side bar.) Even those pesky Chevy guys are putting Mass-Flo's Ford EFI systems on their motors. Yes, you read it right Chevy guys are using Ford parts.

Mass Air or Speed Density?
Other than the outward appearance the Mass-Flo EFI system is based on the tried and true Ford EEC-IV architecture. It uses a factory mass-air computer and all of the standard sensors and actuators, except for the GM mass-air meter and custom throttle body. While plenty of other standalone EFI systems are on the market, many are based on a Speed Density (SD) system. SD is based on a given engines' volumetric efficiency (VE). This requires parameters such as timing and fuel curves to be preprogrammed specifically for an engines VE. These systems are very accurate however require tuning to get up and running and any time the VE is significantly changed - such as with a cam swap or blower install. A mass-air flow system on the other hand can adapt to a very wide range of engine VE because it bases timing and fuel curves on the measured amount of air the engine is bringing in at that moment. So long as the fuel injectors and mass air meter are properly matched to each other and the engine the computer will compensate fairly well for the rest. This is likely why Ford changed over from speed density to mass-air based fuel injection on the Mustang in 1988.

The Mass-Flo EFI system utilizes a carbureted manifold modified for fuel injectors and temperature sensors. We've selected the Edelbrock Victor Jr., the same manifold we ran on our carbureted 331cid engine. Mass-Flo also supplies the high-flow 9/16" fuel-rails.

Sitting a top the manifold is a 1000 cfm "four barrel" throttle body. It has the same flange pattern as a square bore carburetor. A Ford throttle position sensor (TPS) and idle air control (IAC) valve are included.

The Mass-Flo system uses a GM 85mm mass air meter produced by Professional Mass Air Systems (PMAS). The unit is calibrated to your injector size. A machined adapter allows it to sit on top of the throttle body, with an standard air cleaner base sandwiched between the two. As a result the meter is hidden in the air cleaner, given the engine a carbureted appearance. The converter box converts the GM signal to voltage for the Ford EEC.

A custom EEC harness makes getting the system up and running breeze. It has all of the required sensors, relays and fuses.

Since the system is based on the factory stock EEC-IV processor, the sensors are all standard Ford parts. Mass-Flo provides these in their complete kits, or you can source separately as we did.

For the fuel system we selected top quality Mallory pump, filters and pressure regulator. Mass Flo also provides complete fuel systems using Mallory components and Mr.Gasket hose and fittings. In the fuel section we'll go through how to properly select and plumb the components.

Getting it Planned Out and Installed
Mass-Flo can sell you the entire system, including modified manifold, throttle body, mass air meter, fuel rails, injectors, sensors, harness, computer and other pieces. They can even set you up with the entire fuel system. However FordMuscle is about DIY; do-it-yourself and do-it-your way. We didn't want to just cut a check for the entire get up, but rather wanted the challenge of planning and sourcing many of the components ourselves. Mass-Flo is cool with that and will sell you as much or as little as you need.

So go fire up the laptop and kick your feet up, we're gonna take you through every detail of our EFI conversion. We've broken it down by hardware, wiring and fuel. When your done reading this article you'll be prepared to do it yourself and do it right.
(Installing the Hardware )
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In This Article:
Here's everything you need to know about converting from carburetion to mass-air fuel injection. However, we're going to make it look less than obvious with a stealth MassFlo setup. Their specialty is vintage looking EFI systems which retain the classic four-barrel carburetor under-hood appearance.

Also See:
Part II: Getting it to Run
Part III:Dyno Test

DIY EFI: Major Sections
The easiest part is getting your manifold, throttle body and other EFI hard parts installed. Page 2
Getting the EFI harness in is not difficult but takes some patience and planning.
Page 3

Fuel System
We saved the most challenging part for last. Plan it right and install it properly.

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Fuel Inject Any Ford V8
The biggest obstacle to converting a non-Windsor Ford to EFI has been in a lack of a TFI distributor. Since Ford's EEC-IV system uses the distributor signal to sense engine rpm and crank position, and EFI specific distributor is a must. Ford engine families such as the Cleveland and FE never made it to the EFI era so there never was a distributor to use. Mass-Flo has solved this deficiency by teaming up with Mallory Ignition to offer billet distributors with side-mount TFI modules. Even a distributor for the Ford flathead is available. Contact Mass Flo for more information.



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