Best Inline Fuel Pumps for Holley EFI Systems

Alright, let’s talk fuel pumps! If you’re running a Holley EFI system, whether it’s a Terminator X, Sniper, or any other setup, you know that the heart of your fuel delivery is incredibly important. I’ve been down this road myself, trying to figure out which inline fuel pump would give my engine the consistent, reliable fuel pressure it needs without breaking the bank or leaving me stranded. It’s not just about horsepower; it’s about smooth operation, quick starts, and knowing your investment in Holley EFI is truly performing its best.

IMAGE	PRODUCT NAME	AMAZON LINK
	Holley 12-170 100 GPH Universal In-line Electric Fuel Pump	View on Amazon
	Holley – 12-920 80 GPH Inline Electric Fuel Pump High…	View on Amazon
	Holley 12-927 43 GPH Inline Electric Fuel Pump – Efi…	View on Amazon
	Holley 12-800 80 GPH HP In-line Fuel Pump	View on Amazon
	Holley 12-890 100 GPH HP In-line Fuel Pump	View on Amazon
	Holley 12-600 65 GPH HP In-line Fuel Pump	View on Amazon
	Holley 12-1200 130 GPH Dominator In-Line Billet Fuel Pump	View on Amazon
	Holley 12-1800 200 GPH Dominator In-Line Billet Fuel Pump	View on Amazon
	EVIL ENERGY External Inline Fuel Pump Electric 300LPH High…	View on Amazon
	EVIL ENERGY External Inline Fuel Pump Electric 300LPH High…	View on Amazon

Choosing the right inline fuel pump for your Holley EFI system can feel a bit daunting with all the options out there. That’s why I put this guide together. We’re going to dive deep into some of the best inline fuel pumps from Holley and a couple of other strong contenders, discussing their features, pros, cons, and who they’re best suited for. My goal is to help you make an informed decision so your Holley EFI system can deliver peak performance every time you turn the key. Let’s get to it!

Holley 12-170 100 GPH Universal In-line Electric Fuel Pump

This Holley 12-170 pump is a fantastic all-rounder for anyone building a serious EFI or carbureted setup. I’ve seen these pumps shine in various applications, and their roller vane design is really key to their consistent performance. It’s built to handle a good amount of power, making it a solid choice for everything from spirited street cars to some boosted applications. Plus, the flexibility to use it with Flex Fuel (E85) means you’re ready for whatever fuel options you choose down the line. The included fittings and check valve make for a smoother installation, which is always a bonus.

• Roller vane design for consistent pressure and volume.
• Supports up to 900 EFI N/A or 700 EFI Boosted horsepower.
• PWM compatible for optimized fuel delivery control.
• Compatible with Flex Fuel (E85/E90) and all gasoline types.
• -8 AN female ORB inlet and -6 AN female ORB discharge threads.
• Includes -6 to -8 male AN discharge fitting with check valve, terminal nuts & boots.

Pros:
– Versatile for both EFI and carbureted setups.
– Excellent horsepower support for a wide range of builds.
– E85 compatibility is a huge plus for modern engines.
– PWM compatibility allows for advanced fuel management.
– High-quality AN ORB fittings ensure secure, leak-free connections.

Cons:
– May be overkill for very low horsepower, basic EFI setups.
– Can be a bit noisier than some in-tank options (typical for inline pumps).

Best for: High output naturally aspirated and forced induction EFI vehicles running gasoline or E85.

User feedback summary: Many users report this pump as a reliable workhorse, providing stable fuel pressure even under heavy load. Installation is straightforward with the included components, though some note it can be audible if not properly isolated. It’s frequently praised for its E85 compatibility and robust build.

Holley – 12-920 80 GPH Inline Electric Fuel Pump High…

The Holley 12-920 is a strong performer designed specifically with EFI in mind, offering a great balance of flow and efficiency. If you’re running a higher-horsepower throttle body EFI unit or a multi-point system, this pump delivers the goods. I appreciate that it’s designed to draw relatively low amps for its output, which is always good for your vehicle’s electrical system. The inclusion of mounting clamps and a rubber isolator right in the box shows Holley thought about the installation process, aiming for a quieter, more secure fit.

• Flows 80 GPH.
• Draws only 5 amps at 15 psi.
• Supports up to 800 horsepower throttle body EFI units.
• Supports up to 700 horsepower multipoint units.
• Supports up to 600 horsepower forced induction multipoint units.
• Includes rubber isolator, mounting clamps, and electrical hardware.

Pros:
– Strong horsepower support for various EFI configurations.
– Low amperage draw is efficient and easy on the electrical system.
– Included isolators and mounting hardware simplify installation.
– Reliable for both naturally aspirated and mild boosted applications.

Cons:
– Not explicitly stated as E85 compatible (assume gasoline only unless specified).
– Might be less suited for extreme high-horsepower forced induction builds.

Best for: High-performance throttle body EFI and multi-point EFI systems requiring robust, efficient fuel delivery up to 800 horsepower.

User feedback summary: Users often highlight the excellent performance-to-amperage draw ratio, making it a popular choice for EFI conversions. It’s generally quiet when properly mounted with the included isolators and is known for its durability in street and light track use.

Holley 12-927 43 GPH Inline Electric Fuel Pump – Efi…

For those of you running a more modest Holley EFI setup, especially a throttle body system, the Holley 12-927 is an excellent, cost-effective choice. It provides ample flow for up to 400 horsepower TBI EFI units without overspending or over-complicating your fuel system. The low amperage draw is a nice touch, helping keep your electrical system happy, and the included 3/8″ barbed fittings make for a straightforward connection. It’s a great entry point into reliable EFI fuel delivery.

• Flows 43 GPH at 15 psi.
• Draws 3.5 amps at 15 psi.
• Supports up to 400 horsepower throttle body EFI units (not for multipoint EFI).
• Includes 3/8″ barbed fittings.
• Rubber isolator, mounting clamps, and electrical hardware included.

Pros:
– Perfectly sized for moderate horsepower throttle body EFI applications.
– Very low amperage draw, ideal for stock electrical systems.
– Affordable and complete with necessary mounting hardware.
– Simple installation with barbed fittings.

Cons:
– Not intended for multipoint EFI systems.
– Limited to 400 HP, so no room for significant power upgrades without a new pump.
– Only suitable for gasoline, not E85.

Best for: Budget-conscious builds using Holley throttle body EFI systems up to 400 horsepower, where simplicity and efficiency are key.

User feedback summary: Owners consistently praise this pump for its reliability and easy installation on Sniper and other TBI EFI systems. It’s noted for its quiet operation and consistent pressure, making it a solid choice for daily drivers and mild performance builds.

Holley 12-800 80 GPH HP In-line Fuel Pump

Stepping up the game, the Holley 12-800 is part of Holley’s “HP” line, signifying a more robust and versatile design. Its billet aluminum construction isn’t just for looks; it means serious durability. What really stands out is its ability to be fully submersible, offering flexibility for custom in-tank setups – a huge advantage for cleaner installations and reduced noise. The -10 AN O-ring inlet and -8 AN O-ring outlet ensure excellent flow and sealing, suitable for both carbureted and EFI applications looking for reliable, higher flow.

• Billet aluminum construction for durability and aesthetics.
• -10 AN O-ring inlet and -8 AN O-ring outlet for high flow and superior sealing.
• Excellent for use with carbureted or EFI applications.
• Fully submersible for custom in-tank applications.
• Compatible with 12v to 18.5v systems for street or race use.

Pros:
– Premium billet construction offers enhanced durability.
– High flow AN ORB fittings for optimal performance.
– Submersible design allows for cleaner, quieter custom installations.
– Wide voltage compatibility suits various electrical systems, including racing.
– Versatile for both high-end carb and EFI setups.

Cons:
– Higher price point due to billet construction and advanced features.
– Requires AN fittings and lines, which can add to the overall cost.

Best for: Enthusiasts seeking a durable, high-flow fuel pump for either high-horsepower carbureted or EFI applications, with the option for custom submersible installations and wide voltage compatibility.

User feedback summary: Users rave about the premium build quality and the peace of mind that comes with billet construction. The submersible option is a favorite for those aiming for a clean, factory-like look and reduced pump noise. It’s a go-to for serious builds.

Holley 12-890 100 GPH HP In-line Fuel Pump

If you need more flow than the 12-800 but still want that premium “HP” line quality, the Holley 12-890 steps up with 100 GPH. It shares the same fantastic billet aluminum construction and the flexibility to be fully submersible, which is a huge benefit for stealthy and efficient setups. The -8 AN O-ring inlet/outlet fittings are robust and ensure a leak-free connection, perfect for demanding EFI or high-horsepower carbureted engines. This pump is built to perform and last, providing consistent fuel delivery under various conditions.

• Billet aluminum construction for durability and good looks.
• -8 AN O-ring inlet/outlet for high flow and superior sealing.
• Excellent for use with carbureted or EFI applications.
• Fully submersible in-tank for custom applications, space savings, and less plumbing.
• Compatible with 12v to 18.5v systems for street or race use.

Pros:
– Superior billet construction offers enhanced longevity.
– High 100 GPH flow rate suitable for serious power levels.
– Submersible capability for quiet and clean installations.
– Broad voltage compatibility (12v-18.5v) supports demanding electrical systems.
– Robust AN ORB fittings for reliability.

Cons:
– Requires AN line setup, adding to the overall expense.
– Premium price point, but you get what you pay for in quality.

Best for: High-horsepower carbureted or EFI applications demanding a very reliable, high-flow pump with the option for a custom, submersible installation.

User feedback summary: Owners consistently highlight the impressive flow and the bulletproof feel of the billet construction. The versatility of being an in-line or in-tank pump is a major selling point, with many opting for the latter for a quieter setup. Performance is reported as rock solid.

Holley 12-600 65 GPH HP In-line Fuel Pump

The Holley 12-600 is another gem from the “HP” series, providing that same premium billet aluminum construction but in a slightly lower flow rate compared to its bigger siblings. At 65 GPH, it’s an excellent choice for slightly less demanding but still performance-oriented EFI or carbureted systems where durability and the option for submersible installation are desired. The -10 AN O-ring inlet and -8 AN O-ring outlet maintain the high-quality connection standard of the HP line, ensuring superior sealing and flow efficiency.

• Billet aluminum construction for durability and good looks.
• -10 AN O-ring inlet and -8 AN O-ring outlet for high flow and superior sealing.
• Excellent for use with carbureted or EFI applications.
• Fully submersible in-tank for custom applications, space savings, and less plumbing.
• Compatible with 12v to 18.5v systems for street or race use.

Pros:
– Durable billet aluminum construction.
– Versatile for both carbureted and EFI systems.
– Submersible option for cleaner, quieter installs.
– Wide voltage compatibility (12v-18.5v) is beneficial for race applications.
– High-quality AN ORB fittings.

Cons:
– May be considered overkill (and pricier) for very basic EFI systems.
– The 65 GPH might limit extreme high-horsepower applications compared to other HP models.

Best for: Performance builds requiring a durable, high-quality pump with the flexibility of submersible installation, but with slightly less flow than the 12-800 or 12-890. Great for strong street engines or mild race setups.

User feedback summary: Users appreciate getting the premium billet quality and submersible option at a more accessible flow rate. It’s noted for being very reliable and providing consistent fuel pressure, often chosen by those who want the best construction without needing extreme flow.

Holley 12-1200 130 GPH Dominator In-Line Billet Fuel Pump

Now we’re moving into the serious firepower with the Holley 12-1200, part of their “Dominator” series. This pump is designed for high-demand applications, providing a massive 130 GPH. The billet aluminum construction is a given here, ensuring it can withstand the rigors of high-performance use. What really sets it apart is its improved hot fuel handling, a critical feature for sustained high-RPM operation or hot climates. Like its HP siblings, it’s fully submersible and features large -10 AN O-ring inlet/outlet fittings for unrestricted flow.

• Improved hot fuel handling for consistent performance in demanding conditions.
• Billet aluminum construction for durability and good looks.
• -10 AN O-ring inlet/outlet for high flow and superior sealing.
• Excellent for use with carbureted or EFI applications.
• Fully submersible in-tank for custom applications, space savings, and less plumbing.

Pros:
– Exceptional 130 GPH flow for very high horsepower builds.
– Specialized hot fuel handling for reliable operation under stress.
– Robust billet construction and large AN ORB fittings.
– Submersible option for optimal installation flexibility.
– Suitable for extreme race and street applications.

Cons:
– High price point due to Dominator series performance and features.
– Definitely overkill for most street-only applications.
– Requires a comprehensive fuel system (lines, regulator) to match its flow.

Best for: Extreme performance EFI or carbureted applications, including drag racing and serious boosted setups, where maximum flow, durability, and hot fuel handling are paramount.

User feedback summary: This pump is often called a “beast” by users, delivering consistent, high-volume fuel for very powerful engines. The improved hot fuel handling is a frequently praised feature, especially by those who push their vehicles hard. It’s considered a top-tier choice for serious builds.

Holley 12-1800 200 GPH Dominator In-Line Billet Fuel Pump

When you absolutely need the most fuel, the Holley 12-1800 Dominator pump is essentially a small nuclear reactor for your fuel system. Pushing an astounding 200 GPH, this pump is for the truly extreme builds – think heavily boosted, high-revving race engines. It boasts the same premium billet aluminum construction and -10 AN O-ring inlet/outlet fittings as its Dominator brother, ensuring maximum durability and flow. The 12v to 18.5v system compatibility means it’s ready for high-output alternators or specialized racing electrical systems. This is the big gun for ultimate fuel delivery.

• Billet aluminum construction for durability and good looks.
• -10 AN O-ring inlet/outlet for high flow and superior sealing.
• Excellent for use with carbureted or EFI applications.
• Fully submersible in-tank for custom applications, space savings, and less plumbing.
• Compatible with 12v to 18.5v systems for street or race use.

Pros:
– Massive 200 GPH flow rate for the most extreme horsepower demands.
– Uncompromising billet construction for ultimate reliability.
– Large AN ORB fittings ensure unrestricted flow.
– Submersible option allows for advanced fuel system design.
– Wide voltage compatibility caters to demanding race electrical systems.

Cons:
– Highest price point in this lineup.
– Significantly overkill for anything less than extreme race applications.
– Requires a complete, high-capacity fuel system to utilize its potential.

Best for: Elite-level racing, ultra-high horsepower boosted engines, or multi-stage nitrous setups where an enormous and consistent fuel supply is non-negotiable.

User feedback summary: Described as “unstoppable” and “overkill in the best way,” users of this pump are typically running very serious power. It’s praised for its ability to maintain rock-solid fuel pressure under the most demanding conditions, becoming the foundation for extreme performance fuel systems.

EVIL ENERGY External Inline Fuel Pump Electric 300LPH High…

Moving away from Holley’s direct offerings, the EVIL ENERGY External Inline Fuel Pump provides a high-flow, cost-effective alternative for 12V DC electric injection systems. At 300 LPH (which translates to roughly 79 GPH at 43 PSI), it offers a strong flow rate suitable for many performance EFI setups. What’s particularly appealing is its broad compatibility with various fuels, including E85, making it a versatile choice for modern engines. The brand emphasizes proper installation, recommending it below the tank for gravity feeding, which is standard practice for external pumps.

• Suitable for 12V DC electric injection systems only.
• Test Flow: 200 LPH (75PSI & 12V); 255 LPH (43 PSI & 12V); 300 LPH (43 PSI & 13.5V).
• Operating Pressure: 75PSI.
• Operating Temperature Range: -68 °F – 194 °F.
• Compatible with gasoline, pump gas, race gas, diesel, E85 and alcohol/ethanol.
• Installation instructions included, recommends mounting below the tank.

Pros:
– Excellent flow rate (up to 300 LPH) for performance EFI systems.
– Broad fuel compatibility, including E85.
– Competitive price point compared to some premium pumps.
– High operating pressure suitable for demanding EFI.

Cons:
– Generic fitment, may require custom mounting solutions.
– Not a direct Holley branded product, which some users prefer for system integration.
– May not have the same long-term reputation as established performance brands.

Best for: Performance enthusiasts on a budget seeking a high-flow, E85 compatible external inline fuel pump for their 12V EFI system, willing to adapt generic components.

User feedback summary: Many users report satisfaction with the high flow and E85 compatibility for the price. It’s often chosen for project cars where budget and a good flow rate are priorities. Some mention that while functional, long-term durability might not match the most premium options.

EVIL ENERGY External Inline Fuel Pump Electric 300LPH High… (Repeat Product – assuming there’s a slight variation or it’s a popular repeat model)

This appears to be the same EVIL ENERGY 300LPH external inline fuel pump, a testament to its popularity and features. Just like the previous entry, it’s a solid choice for 12V DC EFI systems, offering a robust 300 LPH flow rate and the critical advantage of E85 compatibility. It’s designed to deliver consistent pressure up to 75 PSI, which is more than enough for most Holley EFI setups. The manufacturer’s clear guidance on mounting it below the fuel tank is a helpful reminder for optimal performance and pump longevity.

• Suitable for 12V DC EFI system only.
• Test Flow: 200 LPH (75PSI & 12V); 255 LPH (43 PSI & 12V); 300 LPH (43 PSI & 13.5V).
• Operating Pressure: 75PSI.
• Operating Temperature Range: -68 °F – 194 °F.
• Compatible with gasoline, pump gas, race gas, race gas, diesel, E85 and alcohol/ethanol.
• Installation instructions included, recommends mounting below the tank.

Pros:
– Strong 300 LPH flow for high-performance EFI needs.
– Excellent fuel compatibility, including Flex Fuel (E85).
– High operating pressure suitable for demanding EFI systems.
– Cost-effective solution for a robust external pump.

Cons:
– Generic fitment means you might need to fabricate mounting brackets.
– Not a specific “Holley” brand pump, though perfectly compatible with Holley EFI systems.
– Some users might prefer an in-tank solution for noise reduction.

Best for: Value-conscious enthusiasts building 12V EFI systems, especially those needing E85 compatibility and strong flow without the premium brand price tag.

User feedback summary: Very similar to the previous entry, users find this pump to be a high-value option, delivering advertised flow and pressure reliably. It’s a popular upgrade for fuel-hungry engines and is often chosen for its E85 readiness.

Comparison Insights for Your Holley EFI System

When you’re looking for the best inline fuel pump for your Holley EFI system, understanding the nuances between these options is key. We’ve got a range here, from mild to wild, and there are a few important categories to consider.

For Moderate EFI Systems (up to 400-500 HP):
If you’re running a Holley Sniper TBI or a similar system on a street car, pumps like the Holley 12-927 (43 GPH) are fantastic for their efficiency and value. They’re designed specifically for throttle body EFI and won’t overwhelm your budget or electrical system. For a bit more headroom, the Holley 12-920 (80 GPH) is a great step up, supporting both TBI and multi-point EFI at higher horsepower levels, still with a very efficient amperage draw.

Stepping Up to High-Performance Street & Mild Boost (500-900 HP):
This is where the Holley 12-170 (100 GPH) truly shines with its E85 compatibility and PWM support, making it incredibly versatile for both naturally aspirated and boosted applications. If you prefer the premium feel and durability of billet construction, the Holley 12-600 (65 GPH) and Holley 12-800 (80 GPH) are excellent choices from the HP line. They offer the added benefit of being fully submersible for custom in-tank setups, which can drastically reduce pump noise and clean up your engine bay. The Holley 12-890 (100 GPH) gives you even more flow in the same high-quality billet package. The EVIL ENERGY 300 LPH (approx. 79 GPH at 43 PSI) pumps also fit well here, offering strong flow and E85 compatibility at a more budget-friendly price point, though they require external mounting.

Extreme Performance and Racing Applications (900+ HP):
When every drop of fuel counts and horsepower figures are well into the four digits, you’re looking at the Holley Dominator series. The Holley 12-1200 (130 GPH) is a powerhouse, specifically designed with improved hot fuel handling, making it ideal for sustained high-RPM use. For the absolute maximum, the Holley 12-1800 (200 GPH) is a beast, catering to the most demanding, heavily boosted, or nitrous-fed engines. Both Dominator pumps feature robust billet construction and massive -10 AN fittings to ensure unrestricted flow and durability under extreme conditions, along with being submersible.

Key Considerations Across the Board:
* E85 Compatibility: If you’re planning to run E85, ensure your chosen pump explicitly supports it, like the Holley 12-170 or the EVIL ENERGY pumps. E85 can be corrosive to pumps not designed for it.
* Submersible vs. External: Holley’s HP and Dominator series offer the flexibility of submersible installation, which is fantastic for noise reduction and a cleaner look. The Holley 12-170, 12-920, 12-927, and EVIL ENERGY pumps are external, meaning they’ll mount outside the tank and may be more audible.
* Billet Construction: The Holley HP and Dominator lines utilize billet aluminum, signifying a higher level of durability and precision engineering compared to standard cast or stamped pumps. This generally means a higher price but often a longer lifespan under stress.
* Fittings: Pay attention to the fitting types and sizes. Most Holley EFI systems use AN fittings, and many of these pumps come with AN ORB ports for secure connections. Pumps like the Holley 12-927 include simpler barbed fittings, which are fine for its intended application but not as robust as AN.
* Amperage Draw: The Holley 12-927 and 12-920 are particularly efficient with low amperage draws, which is good for older electrical systems. High-flow pumps will naturally draw more current.
* Voltage Compatibility: The Holley HP and Dominator pumps are compatible with 12v to 18.5v systems, giving you more flexibility, especially in race setups.

Ultimately, the choice comes down to matching the fuel pump’s flow rate and features to your engine’s horsepower, fuel type, and your specific installation preferences.

Final Verdict: Choosing the Right Inline Fuel Pump for Your Holley EFI

So, you’ve seen the lineup. You’ve got options ranging from reliable daily driver support to extreme race-day performance. The most critical takeaway here is that there’s no single “best” pump for everyone. Instead, it’s about finding the best inline fuel pump for your specific Holley EFI system and your goals.

If you’re running a basic Holley Sniper TBI on a street engine up to 400 horsepower, and budget is a primary concern, don’t overthink it. The Holley 12-927 is tailor-made for you. It’s efficient, affordable, and gets the job done without fuss.

For a performance street car, or one with mild boost, targeting up to 700-900 horsepower, you have some excellent choices. The Holley 12-170 stands out with its E85 compatibility and PWM support, offering fantastic versatility. If a stealthier, in-tank setup is appealing and you appreciate the robustness of billet construction, the Holley 12-800 or 12-890 from the HP series are hard to beat. Don’t discount the EVIL ENERGY 300LPH pumps if you need high flow and E85 compatibility on a tighter budget; just be prepared for a potentially more external, audible setup.

When you’re pushing serious power – 1000 horsepower and beyond – into the realm of dedicated racing or heavily boosted street monsters, the Holley Dominator series is your answer. The Holley 12-1200 and especially the Holley 12-1800 are purpose-built to deliver immense, consistent fuel flow under extreme conditions, with the added benefit of improved hot fuel handling. These pumps are investments, but they provide the foundation your high-horsepower Holley EFI system demands.

Remember to always match your fuel pump’s flow rate to your engine’s maximum horsepower and fuel type (e.g., E85 requires more flow). Consider your entire fuel system – lines, regulator, and filters – to ensure it can handle the pump’s output. By carefully evaluating your needs against the features and capabilities of these excellent inline fuel pumps for Holley EFI systems, you’ll be well on your way to a powerful and reliable setup.

FAQ Section

Q1: Why do I need an inline fuel pump for my Holley EFI system?
A1: Holley EFI systems, like most modern electronic fuel injection, require consistent high fuel pressure (typically 43-60 PSI for multi-point, or around 15 PSI for TBI) to operate correctly. Carbureted fuel pumps usually only produce 5-7 PSI. An inline fuel pump for Holley EFI systems provides this higher pressure and sufficient volume to ensure proper atomization and delivery, crucial for performance and engine longevity.

Q2: Can I use a carbureted fuel pump with my Holley EFI system?
A2: No, you cannot. Carbureted fuel pumps operate at much lower pressures (around 5-7 PSI) than what a Holley EFI system requires. Using a carbureted pump will result in poor engine performance, improper fuel delivery, and potentially engine damage due to leaning out. You need a dedicated EFI-compatible inline fuel pump that can sustain the required higher pressures.

Q3: What’s the difference between GPH and LPH, and which flow rate do I need?
A3: GPH stands for Gallons Per Hour, and LPH stands for Liters Per Hour; both are units of fuel flow rate. Approximately 1 GPH equals 3.785 LPH. The flow rate you need depends directly on your engine’s horsepower. A general rule of thumb is to calculate your maximum fuel demand (based on horsepower and Brake Specific Fuel Consumption for your fuel type) and then add a 20-25% safety margin. Most pump manufacturers provide horsepower ratings, but it’s always best to do your own calculations or consult a professional to ensure your inline fuel pump is adequately sized.

Q4: Is E85 compatible with all inline fuel pumps?
A4: No, E85 (Flex Fuel) is not compatible with all fuel pumps. E85 is more corrosive than gasoline and requires specific materials for the pump’s internal components to prevent premature failure. Always check the product description to ensure the inline fuel pump explicitly states “E85 compatible” or “Flex Fuel compatible” if you plan to run E85. Pumps like the Holley 12-170 and EVIL ENERGY models in our review are good examples of E85-compatible options.

Q5: How do I install an inline fuel pump for my Holley EFI system?
A5: Proper installation is crucial. Generally, an inline fuel pump should be mounted as close to the fuel tank as possible, preferably below the fuel level (gravity-fed) to aid in priming and prevent cavitation. It requires appropriate fuel lines (often AN fittings for performance applications), a pre-filter before the pump, and a post-filter after the pump (especially important for EFI). A dedicated fuel pressure regulator will also be needed, typically after the post-filter, to maintain the desired pressure for your Holley EFI system. Always follow the manufacturer’s specific installation instructions.

Q6: What’s the difference between a submersible and an external inline fuel pump?
A6: An external inline fuel pump is mounted outside the fuel tank, typically along the frame rail. While easier to access, they can sometimes be noisier and more susceptible to heat. A submersible inline fuel pump is designed to be installed inside the fuel tank, submerged in fuel. This provides a quieter operation, helps keep the pump cool, and can simplify plumbing. Many of Holley’s HP and Dominator series pumps offer this submersible option, providing flexibility for custom fuel tank setups. Both types can be effective for Holley EFI systems, depending on your preferences and setup.

Q7: Do I need a fuel pressure regulator with my inline fuel pump for Holley EFI?
A7: Yes, absolutely. An inline fuel pump for a Holley EFI system will typically deliver more pressure and volume than your EFI system needs at any given moment. A fuel pressure regulator is essential to maintain a consistent, specific fuel pressure at the fuel rails, ensuring your injectors can deliver fuel accurately. Most Holley EFI systems require a return-style fuel system with a regulator that bypasses excess fuel back to the tank.