OBS Fuel System Upgrade

December 18th, 2011

By Kevin Wilson

Photography: courtesy of Driven Diesel

Lots of Ford lovers say that the ’94-’97-model Power Strokes were the last diesel trucks from Ford with character.

Driven Diesel’s New Regulated Return for the ’94-’97 Power Stroke

Among Ford purists, the last great Ford diesel truck ever produced with any styling character was the old body-style (OBS) Power Stroke.

These round-nosed beauties were the predecessors of the Super Duty and are fitted with a similar version of the 7.3L Power Stroke that eventually ended up between the fenders of the Super Duty.

Unfortunately, when it comes to aftermarket upgrades, it’s kind of slim pickings for the OBS Fords—while there is a plethora of parts available for the Super Duty.

One company hoping to change that is Driven Diesel, of Phoenix, Arizona. This company is famous for its regulated return fuel systems for both the 7.3L and 6.0L Super Duty Power Strokes and has just developed a similar system for the ’94-’97 OBS Ford trucks. The system eliminates the factory mechanical fuel pump and fuel bowl assemblies from the engine valley, setting the stage for upgrades such as high-pressure oil system pumps and larger injectors and turbos, as well.

When you open the hood of an OBS Ford, here’s the setup you’ll see. The round gizmo in the front of the motor is the fuel bowl, with the pressure regulator to the right.

Since the kit does away with the mechanical fuel pump, Driven Diesel recommends that owners install a high-quality fuel pump and filtration system that can achieve a 65psi operating pressure. It also recommends a 2-micron fuel filter between the pump and injectors as a last line of defense to protect the injectors. The pump upgrade and filter system do not come with the kit, but Driven Diesel is working on its own system that is compatible with its OBS kit.

According to Driven Diesel, the kit does away with the weak and usually well-worn, cam-driven mechanical fuel pump that is mounted in the valley of the motor, along with the stock fuel lines. While these can support a stone-stock 7.3L, no diesel enthusiast even leaves his truck stock for long, so the fuel system upgrade is a great place to start. Driven Diesel says the upgrade improves the 7.3 dramatically by offering quicker starting, quieter engine operation, improved throttle response and power, and better fuel economy.

The kit fits trucks with either a stock or upgraded turbo and is compatible with aftermarket high-pressure oil pumps. Unlike Driven’s late-model 7.3L kit for Super Dutys, which converts the fuel system from a “dead head” setup to a regulated return, the OBS system upsizes the factory fuel feed and return lines with stainless steel fittings and 3/8-inch braided Teflon® hoses for maximum flow. This sets the stage for any injector upgrade by ensuring adequate fuel flow and pressure.

The kit comes complete with four-color instructions and offers additional installation tips, along with a note on recommended fuel pump and filtration requirements.

Installation is a bit more than a typical bolt-on, with the majority of the work involving removing all the stuff from the top of the engine. Our installer for the kit is Strictly Diesel, of Phoenix, which sells Driven Diesel products through its retail sales division.

Strictly Diesel recommends using plenty of penetrating oil on the turbo flanges and exhaust up-pipe bolts and nuts the night before to assist in removal.

Rather than give you a bolt-by-bolt install, we’ll hit the highlights in the following photos. If you’ve got an OBS Ford and are looking to upgrade it with larger injectors, turbo, etc., Driven Diesel’s Regulated Return Fuel System is a great place to start.


Strictly Diesel



This is in the December issue of Diesel World magazine.

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