Fuel For Thought: Choosing The Best Fuel System For Your EFI Upgrade

We are sure you are nostalgic about your first car. Who could forget the distinctive guttural roar of the secondaries opening up on the Quadrajet carburetor as you stepped on the loud pedal? But even if you tend to look through rose-colored glasses, you likely recognize the benefits of a well-sorted-out electronic fuel injection (EFI) system. After all, what’s not to love about increased part-throttle driveability, easier cold starting, and even better fuel economy?

With self-learning fuel injection systems available from companies such as FiTech EFI, it’s never been simpler to reap the benefits of EFI. However, if you’re swapping to such a system, you’ll need to address your fuel system before you get your vehicle wired and fired. A carbureted fuel system’s mechanical or low-pressure fuel pump will not deliver enough fuel pressure to run EFI.

EFI fuel system

The Force Fuel System holds a half-gallon of fuel. It simply connects to the vehicle’s existing fuel system in place of the carburetor’s fuel line and uses the engine’s existing mechanical or low-pressure electric fuel pump (4-6 psi) to fill its reservoir. The housing includes a 340-lph high-pressure pump and an integral regulator set at 58psi.

FiTech offers a variety of throttle-body and port fuel injection systems to support up to 800hp. But just as one size doesn’t fit all for those systems, FiTech gives the enthusiast a number of EFI fuel system options to deliver fuel from the tank to the injectors.

Whenever I sell an EFI unit, I always recommend the in-tank pump first and the inline last. The in-tank pumps stay cooler, run more quietly, have ‘first dibs’ at fuel, and last longer. – Mike Wahl, FiTech

Forced Fuel

FiTech introduced its trick, extruded and machined aluminum Force Fuel System in August 2019. It’s a much-improved version of the company’s discontinued Command Center, says FiTech Sales Manager Mike Wahl. To keep the submerged EFI-pump cool, the Force Fuel System holds a half-gallon of fuel. It simply connects to the vehicle’s existing fuel system (in conjunction with the carburetor’s fuel line) and uses the engine’s existing mechanical or low-pressure electric fuel pump (4 to 6 psi) to fill its reservoir.

The housing includes a 340-lph, high-pressure pump, an integral regulator set at 58psi, and a serviceable 10-micron fuel filter. This EFI fuel system is designed to return excess fuel to the gas tank, so a fitting is included to install a return port in the fuel tank or fuel cell. FiTech also supplies -6 AN fittings, high-pressure fuel hose, and a liquid-filled gauge. And, it’s even designed to be compatible with E85, ethanol and methanol fuels, and it will push enough fuel to support 800hp on naturally aspirated vehicles using gasoline.

As factory-assembled, the Force Fuel System's bracket is installed on the bottom of the housing. It's easily swapped to the side of the housing to allow for a range of mounting options, at any angle, except upside-down.

The versatile mounting bracket is removable to allow a number of mounting options, and Wahl notes that most installers place the unit on the radiator support or firewall.

“It can be mounted on its side, straight up and down, or you can mount it at any angle, except upside-down. We see a lot of customers using these in autocross, off-road, and any off-camber usage because it eliminates tank-slosh. It’s also ideal for the average hot-rodder. Customers who do not want to modify or replace their fuel tank love this option because of the ease of the install on just about any application. It’s one of our top sellers at the moment.”

EFI fuel system

The low-profile billet top mount of the Go Fuel universal in-tank pump module is designed to ease installation. The supply and return ports are positioned parallel to ease routing of the fuel lines. The vent port is on the other side of the mount.

Go Fuel In-tank Module

The Go-Fuel universal in-tank pump module combines the same 340-lph fuel pump found in the Force Fuel System, but the pump mounts to an in-tank hanger and installs in a factory tank. This installation requires cutting a hole in the tank. The hanger is adjustable for depths of 6 to 15 inches to accommodate most tanks with the supplied hardware.

If using a tank not designed for EFI pumps, there will be no baffle installed. For those tanks, an oversized 35 square-inch pump filter (commonly known as a “sock”) is also included as an option to the standard 11 square-inch sock to ensure uninterrupted fuel delivery to the pump. The larger filter helps combat fuel slosh issues, which could otherwise interrupt fuel being picked up by the pump. Push-lock-style AN fittings are also included, as are gaskets and wiring terminals.

The Go Fuel In-Tank Module, PN: 50015 (left), is a universal installation in many tanks. It includes an 11 square-inch filter sock for baffled tanks and a 35 square-inch filter sock for unbaffled tanks. PN: 40102 is the replacement pump for the Go Fuel In-Tank Module, the discontinued Command Center, and the new Force Fuel PN: 50004.

The low-profile billet mount places the supply and return ports in a parallel position to ease routing the fuel lines. The vent port is facing the other side of the mount to ease routing the line near the fill tube.
FiTech also teamed up with Tanks, Inc., to offer an EFI fuel system kit for many popular applications that includes a new tank, mounting straps, pump module kit, and sending unit. For those tanks, the Go Fuel in-tank module is a direct fit.

The Go Fuel in-tank module is also available as a kit, complete with a Tanks, Inc. fuel tank and sending unit.

Inline Fuel Pump May Be The Best Option For Some Installations

An external (inline) fuel pump system (PN: 50001), is also another option from FiTech. It’s a comprehensive EFI fuel system that includes a 255-lph fuel pump designed for engines making up to 650hp. The kit includes 40 feet of EFI-grade, 3/8-inch fuel hose for the supply and return lines, two billet aluminum fuel filters, a 60-micron pre-filter, a 30-micron post-filter, push-lock hose ends, and a mounting clamp for the pump.

The inline pump is often easier to install and access, so it’s quicker to replace should a failure occur. Some reasons to choose this type of EFI fuel system would be if it is not possible to modify or replace the fuel tank. Inline pumps are often cheaper, Wahl says.

“But, we sell our PN: 50015 kit for $229.00 (U.S.), which, for the benefits, is well worth it.”

FiTech's PN: 50001 fuel delivery kit includes the external inline 255-lph fuel pump, mounting bracket, fittings, pre- and post-filters, and fuel hose.

Still, inline pumps are typically not Wahl’s first choice. Since an in-tank pump is submerged in fuel, it will run more quietly and usually last much longer.

“Whenever I sell an EFI unit, I always recommend the in-tank pump first,” he says. “The in-tank pumps stay cooler, run more quietly, and have ‘first dibs’ at fuel. The in-tank pumps tend to last longer.” Inline pumps typically fail more often than in-tank pumps because they rely on gravity to supply the fuel to the pump and then must push the fuel forward.

“If the feed is starved or cut-off, you damage the pump and cause a shortened life. If the pump isn’t below the fuel supply and within two feet of the fuel supply, you can damage your pump. If any fuel cavitation takes place, you guessed it, you damage your pump,” he states.

What Installation Issues Can Trip You Up?

Wahl notes that most of the installation errors the tech line diagnoses are for the EFI units themselves. It’s important to have a clean ground cable and frame-mounting point free of corrosion. And of course, if you’re using an existing tank, make sure the inside is clean.

“Modern vehicles run an average of eight ground cables,” Wahl says. In classic cars, we are lucky to see two. Poor grounding becomes an issue when converting over to fuel injection. For power, the FiTech’s battery wire needs to go to the battery…not the starter, not to the junction box, straight to the source of the power.”

The most common issue in converting from carburetors to fuel injection is that “EFI is extremely picky,” Wahl says. “It will expose almost any issue you have with your engine that the carburetor was covering up. Vacuum and exhaust leaks are usually the top issues. The next common issue that we see a lot of, is older vehicles don’t have a 12-volt ignition system or they have ballast resistors ‘dumbing down’ the voltage. That will mislead the EFI unit and cause driveability issues.”

Whatever application you have in mind, having a proper EFI fuel system is paramount to a flawlessly functioning EFI. With the help of FiTech, it’s never been simpler to get your classic ride updated for the 21st century.

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About the author

Jay Sicht

Since childhood, Jay has been fascinated by planes, trains, and automobiles, and all things mechanical. He's been in the automotive aftermarket for 25 years, having written about it for 15 of those years.
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