Wayne Cook
August 1, 2000

Step By Step

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The Holley Multi Point Injection kit comes with all of the major components: an upper intake; a lower intake with the fuel rails already in place; a Holley 70mm throttle body; an electric, high-pressure fuel pump; an engine-control module and wiring harness; and software for programming. Connectors for fuel and electrical are also included.
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This close-up of the Holley lower intake manifold shows the gigantic intake ports found on the SysteMax setup, which make it more of a high-performance upgrade over the basic swap to factory 5.0 fuel injection.
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A number of additional parts were required to complete the Holley MPI installation in our vintage Mustang. Shown are the new distributor and distributor TFI module; Chrysler idle-speed motor; and high-performance, high-pressure fuel filter to be used directly before the engine. Fuel hose to join the fuel rails and also to go to the pressure regulator are shown along with a throttle cable-mounting bracket, which attaches to the throttle body.
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You’ll need some high-quality hose, like this 250-psi–rated Aero Quip line, and various AN fittings to complete a safe high-pressure fuel delivery and return system. Other things needed but not shown include a set of low-profile valve covers, a mechanical fuel-pump block-off plate, and an inertia switch to interrupt fuel flow in an emergency. Alternative shock-tower-to-firewall braces will be needed to clear the fuel-injection upper, and also an elbow fitting for the air-intake-to-throttle-body with air cleaner.
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Under the hood on our ’66 Mustang, we’ve already removed the carb and intake manifold as well as the shock-tower-to-firewall braces. For now, the distributor cap and plug wires are still in place.
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From inside the car, determine where a hole can be made to allow access for the wiring harness. The processor must be located inside the car where it can stay cool and dry. On our car, you can see our firewall hole (with white paper behind it for clarity) just beneath the hood hinge.
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This throttle cable is from a Fox Mustang and will attach perfectly to the throttle body. A small hole in the firewall near the pedal assembly is needed to provide access for the cable. The attached bracket on the cable casing allows attachment of the cable assembly to the firewall using one fastener.
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Inside, you’ll need to go with an alternative pedal arrangement. The standard mechanical-linkage pedal won’t work, so we used a 5.0 Mustang pedal assembly with a Windsor-Fox pedal adapter bracket.
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After some trial and error, we decided to locate our fuel-pressure regulator beneath the hood hinge in the position shown. It’s important to keep the regulator away from any heat source, like exhaust components or heater hoses.
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Because an electric fuel pump replaces the mechanical pump, a pump block-off plate will be needed. Don’t forget to use a new gasket.
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The Motorsport valve covers, originally on our car, look great and offer plenty of clearance for roller rockers, but they’re too tall to clear the fuel-injection manifold. We switched to a pair of standard 5.0 Mustang valve covers. The oil-fill baffle on the 5.0 covers can be relieved to clear aftermarket rocker arms.
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Preparation of the lower intake must include the installation of this PCV screen and grommet. Without the screen, oil will enter the PCV system. Use a new PCV valve to insure the proper operation of this system.
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AN fittings and high-pressure hose were used to join the two fuel rails together. It is far easier to accomplish this with the lower manifold off the engine.
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We used new ROL gaskets and location studs to be sure the lower intake was sealed and seated correctly. Gasket sealer was applied and allowed to set-up to function as end seals. We’ve said it many times; if you don’t get the intake seated on the cylinder heads properly you’ll risk three kinds of leaks: oil, water, and vacuum.
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With the lower intake situated on the engine, a torque wrench is used to tighten down the manifold in the correct bolt sequence.
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We used this old distributor cap with a “homemade” window to install our distributor. With this cap there’s no mystery where the rotor is with relation to the No. 1 plug-wire position.
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A small amount of grinding on the fuel rail AN plug was necessary to clear the distributor housing. This might be avoided by using an interior plug that would sit flush with the rail end.
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With the lower manifold and distributor in place, the long process of making the electrical connections begins. Here, we see the electrical leads going to the individual fuel injectors.
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Holley includes this adapter to allow the distributor TFI module to be connected to the harness.
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Our main harness plug was routed through the firewall and into the glovebox area. The processor is shown ready to be installed behind the glovebox door. For an early Mustang, this is the best place to locate the computer. The smaller white plug shown resting on the glovebox door is the connector that attaches to a laptop.
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To prepare the upper intake for installation, we’ve already installed the EGR spacer and throttle body, and now the Chrysler idle speed motor goes into place.
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Here, the throttle-position sensor is carefully fastened into place. It’s important to handle the delicate sensors carefully.
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This photo shows how the stock 5.0 Mustang throttle-cable bracket is fastened onto the throttle body. Behind the bracket, the vacuum tee with its many outlets is shown. How many of these fittings are used depends on your specific requirements.
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It’s almost time to install our upper intake manifold. First, we installed our manifold-mounting studs, followed by the included upper intake gasket.
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Once the upper intake is down, tighten the fasteners gradually and evenly. This upper is easy to install compared to some. The long bolt passes through the upper intake, so there’s no struggling to tighten fasteners inside the intake.
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The fuel fittings we used required no clamps, but the fuel hose must be forced onto the fitting with great pressure as seen here.
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The special, high-pressure fuel filter was purchased separately and mounted in the back area of the wheelhouse. The hose going toward the engine compartment is headed to the fuel-pressure regulator.
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The high-pressure fuel system required by the EFI calls for a return line, so we had to drain the fuel from the tank to mount the fitting. Luckily, our tank had a drain plug to accommodate this return line.
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We experimented with a variety of locations for our Holley electric fuel pump. Electric pumps push fuel more effectively than pulling it, so a location as close as possible to the tank was selected.
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Our new fuel line now runs down the opposite side of the car, as opposed to the factory line. The arrangement here accomplishes this change of direction as the tank outlet is pointed to the old line. The small filter ahead of the fuel pump will protect the pump from any accumulated debris in the tank.
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Alternative shock-tower-to-firewall braces had to be found. This firewall bracket will receive the new braces coming from the shock tower. We bought our brace kit from Windsor-Fox.
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Here’s the completed installation except for an intake duct and a K&N air filter. Remember, the speed-density arrangement requires no air meter, so an early 5.0 speed-density duct from Ford will work perfectly. Check future issues of Mustang & Fords for performance updates on this interesting Holley system. MF

We’re always interested in new components designed to improve the power and driveability of our vintage Fords. For basic street induction, we know it’s hard to beat a good four-barrel carburetor, and of course Holley offers a terrific selection of four-hole carbs for Fords. But Holley has also been in the fuel-injection field for a while now, offering the excellent SysteMax upper and lower intake systems for late-model 5.0 engines. The company has also offered the Pro-jection fuel-injection arrangement where the injector body bolts on like a carburetor.

At last winter’s Specialty Equipment Marketing Association (SEMA) trade show, Holley introduced a new Ford fuel-injection system, a Multi Point design that utilizes the tried-and-true SysteMax upper and lower intake manifold and Holley throttle body along with a Holley-produced engine control module, or processor, and wiring harness for adapting the system to carbureted vehicles. With Holley’s kit, you get all the major components for converting carbureted cars, like vintage Mustangs and Fords, to ultra-modern, programmable fuel injection. Depending on your application, you will more than likely need a few additional components to make the swap complete.

The fuel injection used with Holley’s kit is a speed-density type with batch-fire injection. Why a speed-density batch fire as opposed to the factory Ford ECC IV arrangement which offers mass air technology along with individual injection for each cylinder? The fact is, the Ford setup is not programmable. You hook it up and it runs, making its own adjustments along the way with the mass air technology that allows the computer to compensate for changes in engine components. The great feature of the new Holley MPI is that the computer is completely programmable with a laptop computer. The speed-density method of monitoring air intake is not a stumbling block to installing high-performance engine components because you can adjust the processor to operate the engine efficiently and optimally regardless of the cam or compression. Air/fuel mixture, idle, rev limiter—it’s all in there for you to decide.

Holley furnished us with the MPI kit for installation and testing on a ’66 Mustang fastback. The car already had a GT-40 crate engine installed, so we knew we wouldn’t be trying out the latest technology on a tired 289. Follow along as we detail the installation of the Holley Multi Point Injection setup on this previously carbureted small-block. We’ll show you what’s involved in getting the kit on the car, and discuss the things you’ll need to complete the job that are not included. At a future date, after we’ve had a chance to dial everything in, we’ll take a look at what the results are and reveal the performance enhancements.