Faster Starts, More Horsepower: Why You Should Add an Electric Fuel System to your ’94.5-’97 Power Stroke

• November 26, 2021
• Story By
  Mike McGlothlin

For more than 20 years, diesel heads have been modifying the 7.3L Power Stroke. But of the countless upgrades you can perform on the first diesel V-8 to wear the Power Stroke name, the original ’94.5-‘97 version needs the most help in the fueling department. Not only are the fuel injectors in these initial, HEUI-fired engines small, but the fuel pressure they see isn’t always consistent—and is almost always on the low side of what is considered “acceptable.” A lack of adequate fuel supply can place injector longevity in question, not to mention hold back any performance gains you plan to get out of an injector upgrade.

This is why an electric fuel system is a must-have item for your ’94.5-’97 Ford. Trust us, ditching the factory, cam-driven lift pump in favor of an electric unit—along with larger supply lines—will change your 7.3L’s life. Not only with the injectors see a life-extending 65-psi worth of fuel supply pressure at all times, but you’ll experience crisper, quicker starts, a smoother, quieter idle and horsepower gains of 20 to 40 hp depending on the extent of your other modifications. As a bonus, most basic electric fuel (E-fuel, for short) systems for the early 7.3L can support more than 500rwhp. That means no switching anything out when you’re ready to upgrade to larger injectors. For both reliability and performance, E-fuel is a sound investment.

Rule #1. The Stock Lift Pump Has To Go

The mechanical lift pump on the ’94.5-’97 7.3L Power Stroke is cam-driven, actuated via a tappet and mounted in the lifter valley. Although it’s advertised as providing the injectors with 40-70 psi worth of fuel pressure, 40 to 45 psi is typically all that’s observed. Even for stock injectors, this is barely adequate fuel supply pressure for the injectors to see. For best injector life and performance, 65-psi is generally accepted as the ideal pressure for 7.3L injectors. Once the factory lift pump is removed in favor of a chassis-mounted electric pump, the left over hole in the block has to be plugged.

A Bit Laborious, But 110-Percent Worth It

Most aftermarket electric lift pump systems require larger diameter fuel lines (the factory lines are tiny by modern standards) and/or different fuel line routing in the engine bay. This makes accessing the fuel supply fittings at the rear (firewall side) of the cylinder heads necessary. These fittings introduce fuel supplied from the lift pump into the fuel galleries within the heads, which in turn feed the injectors. In order to reach the driver side fitting, the turbocharger has to be removed.

Complete E-Fuel Kits

A comprehensive electric fuel system for the ’94.5-’97 7.3L Power Stroke will look something like this: pump, fuel hose, filters, a mounting bracket, wiring, necessary mounting hardware and (not pictured) the parts required to run a regulated fuel return arrangement. With the hard lines measuring just 5/16-inch in diameter on the early 7.3L, even 3/8-inch supply lines are an improvement—and bumping up to ½-inch line is a whole new world in terms of flow and horsepower potential. Irate Diesel Performance offers two comprehensive OBS electric fuel supply systems. It’s competition system is shown above. Some other major players in the 7.3L E-fuel game are Driven Diesel, Bean’s Diesel Performance and DieselSite.

No Shortage Of Proven Lift Pump Choices

The stock Bosch unit found on ’99-’03 Super Duty 7.3L’s, the Walbro GSL392, the Fuelab Prodigy 41401-1 pump and even the Aeromotive A1000 have all been used successfully and reliably in the 7.3L aftermarket for years. In fact, most comprehensive electric fuel supply systems for the ’94.5-’97 7.3L are based around the use of one of the aforementioned lift pumps. With proper filtration and regular filter changes, either pump will live just fine in a daily driven application, but high horsepower goals (more than 500rwhp) tend to rule out the Bosch and Walbro units. Just make sure you run 10-gauge wire to power the A1000 should you go that route (ask us how we know…).

Return Side Upgrades

Regulating the return side of a 7.3L’s electric fuel system is key, and regulated return kits are often included with comprehensive E-fuel systems. In addition, most electric fuel systems come with an adjustable regulator and a liquid-filled fuel pressure gauge so that you can set fuel pressure exactly where you want it—not to mention that it can also help you troubleshoot fuel supply issues if necessary. In systems geared toward performance (i.e. ½-inch or larger supply lines), it always pays to run a larger diameter return line to the tank, too. Relying on an undersized return line can lead to excessive pressure, especially at idle when most fuel is returning to the tank.

The Fuel Selector Valve: Another Bottleneck

One predicament that horsepower-seeking, early 7.3L Power Stroke owners face is the bottleneck that is the OEM fuel tank selector valve. This is what allows you to switch between the front and rear fuel tank on ’94.5-’97 F-series trucks. The problem is that its internal passages only measure 5/16-inches, which limits you to the 500 to 550rwhp range. Granted, we’ve seen 590rwhp squeezed out of it in the past on the chassis dyno, but fuel supply pressure was falling like a rock. If you plan to keep things around 500rwhp or less feel free to retain the selector valve, but if you’re hungry for more ponies than that make sure you bypass it. However, don’t scrap it altogether. If you want your old Ford’s fuel gauge in the cluster to continue to work, you’ll have to leave it plugged in and hanging along the frame rail.

Chassis-Mounted, Safely Out Of Harm’s Way

Here, you can see an Irate Diesel electric fuel system present on a ’94.5-’97 Ford F-350, drawing fuel from a sump installed in the bottom of the factory tank. In this particular application, the factory rear tank has been eliminated (which was done to take the restrictive factory selector valve out of the equation). Notice the Baldwin spin-on fuel filter and water separator, which provide the fuel system and injectors all the protection they need. In case you’re wondering what happens with the factory fuel filter reservoir under the hood, nine times out of 10 it gets deleted when an electric fuel system goes in. Not only does scrapping the factory fuel bowl eliminate several fuel-related choke points in the lifter valley, but filter changes are simplified along the truck’s frame rail. This means you’re no longer draining fuel off of the back of the engine during a filter change or dealing with leaks when an O-ring fails.

Gains From Idle To Wide-Open Throttle

Electric fuel and the more consistent fuel supply pressure it brings leads to quicker starts, smoother idle, more power and can even improve fuel economy. On the horsepower front, being able to maintain a steady 65-psi of supply pressure can make a noticeable difference on the dyno. In our time spent strapped to the rollers testing old body style Fords, we’ve seen gains as high as 17 hp and 33 lb-ft of torque after installing an electric fuel system. With bigger injectors, a larger turbo and other supporting modifications on board, those gains can easily double—especially if you’re going from the stock mechanical lift pump and tiny supply lines to a high-flow electric system with a Walbro, Fuelab or Aeromotive pump.