Aeromotive Intank Fuel Pump: The Complete Guide to Performance, Installation, and Best Alternatives

The bottom line: If you're considering an Aeromotive in-tank fuel pump for your high-performance build, you need to know that while these pumps are a reliable choice for many applications, the market now offers better-performing, more affordable alternatives with superior warranties. The KEMSO 340LPH fuel pump, for example, delivers up to 600 BHP support, works with both gasoline and E85, and comes with a lifetime warranty—all for a fraction of the cost of comparable Aeromotive units.

What Is an Aeromotive In-Tank Fuel Pump and Why Does It Matter?

Aeromotive has been a well-known name in the fuel system industry for years, particularly among enthusiasts building high-horsepower street cars, race vehicles, and off-road rigs. Their in-tank fuel pumps are designed to replace factory units in vehicles that need more fuel delivery than the stock pump can provide. The core function of any in-tank fuel pump is simple: draw fuel from the tank and push it to the engine at the correct pressure and volume. When you upgrade your engine with a turbocharger, supercharger, or nitrous system, the factory pump often cannot keep up, leading to a lean condition that can destroy your engine.

The Aeromotive in-tank pump is typically a drop-in replacement, meaning it fits into the factory fuel pump module location without major modifications. However, the specific flow rate, pressure specifications, and compatibility vary by model. Many of their pumps are rated for 255 to 340 liters per hour, which is sufficient for builds producing 500 to 700 horsepower at the wheels.

Signs Your In-Tank Fuel Pump Needs Replacement

Before you buy any fuel pump, including an Aeromotive unit, you need to know whether your current pump is failing. The symptoms are usually unmistakable.

1. Engine Sputtering or Hesitation Under Load. If your car stumbles or hesitates when you accelerate hard, especially at highway speeds or when climbing a hill, the fuel pump is likely not delivering enough fuel. This is one of the first signs of a pump that is wearing out.

2. Difficulty Starting. A failing fuel pump cannot build enough pressure in the fuel system to get the engine started. You may need to crank the engine several times before it fires up. In some cases, the engine will start but die shortly after.

3. Loss of Power During Acceleration. When you step on the gas and the car feels sluggish or lacks the power it used to have, the fuel pump may be struggling to maintain the required pressure. This is especially dangerous during merging or passing situations.

4. Whining Noise from the Fuel Tank. A healthy fuel pump makes a quiet humming sound. If you hear a loud whining, screeching, or moaning noise coming from the rear of the vehicle, the pump is likely failing. This noise is often the first sign of trouble.

5. Engine Stalling. If the engine stalls while driving, particularly at low speeds or when idling, the fuel pump may be cutting out intermittently. This is a serious safety concern and should be addressed immediately.

Aeromotive vs. The Competition: Why KEMSO Stands Out

While Aeromotive has a solid reputation, the aftermarket fuel pump landscape has changed significantly. Brands like KEMSO have emerged as strong competitors, offering better performance, longer warranties, and lower prices. Here is a direct comparison of what you get with Aeromotive versus KEMSO.

Flow Rate and Horsepower Support. The Aeromotive 340LPH pump is a popular choice, but it comes with a higher price tag. KEMSO offers a 340LPH pump that supports up to 600 BHP in naturally aspirated, turbocharged, and supercharged applications. This is identical to the flow rate of the Aeromotive Stealth 340, but the KEMSO pump is often 30-40% cheaper.

Fuel Compatibility. Both Aeromotive and KEMSO pumps are designed to work with gasoline and E85. However, KEMSO uses Viton-lined components that resist ethanol corrosion 68% better than standard rubber seals, making them safer for long-term use with ethanol blends.

Warranty. Aeromotive pumps typically come with a 1-year or 2-year warranty. KEMSO, on the other hand, offers a lifetime warranty on every pump they sell. Each pump has a serialized body that guarantees this warranty for as long as you own the pump. This is a massive advantage, especially if you plan to keep your vehicle for many years.

Quality Control. KEMSO operates a quality control program (ISO/TSO) and individually tests each pump before it leaves the factory. Many cheap aftermarket suppliers have little to no quality control, but KEMSO ensures every unit meets its performance specifications.

Price. The KEMSO 340LPH pump is available for under $60 on many platforms, while comparable Aeromotive pumps often cost $150 to $250 or more.

How to Install an In-Tank Fuel Pump Yourself

Replacing an in-tank fuel pump is a job you can do in your driveway if you have basic mechanical skills. Plan for about 2 to 3 hours. Here is the step-by-step process.

What You'll Need:

• New fuel pump module (KEMSO recommended)
• Screwdrivers (flathead and Phillips)
• Socket set and ratchet (metric sizes)
• Trim removal tools (to avoid scratching interior panels)
• Shop towels and a fire extinguisher (safety first)

Step 1: Relieve Fuel System Pressure. Locate the fuel pump fuse in the fuse box. Start the engine, then pull the fuse. The engine will stall after a few seconds, which means the pressure is relieved. Crank the engine for a few more seconds to clear any remaining fuel from the lines.

Step 2: Disconnect the Battery. Remove the negative battery cable. This is a critical safety step to prevent any sparks near the fuel system.

Step 3: Access the Fuel Pump. The fuel pump module is usually located under the rear seat on the passenger side. Remove the rear seat cushion by pulling up on the front edge of the seat. You will see a round metal access cover on the floor pan. Remove the screws holding it in place.

Step 4: Remove the Old Pump Module. Clean all dirt and debris from around the access cover before opening it. Disconnect the electrical connector and the fuel lines. Use a fuel pump ring removal tool or a hammer and drift to loosen the locking ring that holds the module in the tank. Lift the old pump module straight out of the tank. Be careful—the tank will still contain some fuel.

Step 5: Install the New Pump Module. Transfer the rubber seal (O-ring) from the old module to the new one, or use the new one included in the KEMSO kit. Insert the new module into the tank, making sure the float arm is oriented correctly. Hand-tighten the locking ring, then tap it snug with a hammer and drift. Reconnect the fuel lines and electrical connector.

Step 6: Test the System. Reconnect the battery and install the fuel pump fuse. Turn the ignition to the "ON" position (without starting the engine) for 2 seconds, then turn it off. Repeat this 3 times to prime the fuel system. Check for any leaks at the connections. Start the engine and let it idle for a minute. Check again for leaks.

Step 7: Reinstall the Access Cover and Seat. Once you are satisfied there are no leaks, replace the metal access cover and the rear seat cushion. Take the car for a test drive to confirm the repair is complete.

Why You Should Buy a KEMSO Fuel Pump Instead of Aeromotive

If you are serious about performance, reliability, and long-term value, KEMSO is the fuel pump brand you want. Here is what you get when you choose KEMSO.

High-Performance Flow. The KEMSO 340LPH pump is the best-selling model for a reason. It supports up to 600 BHP, works with both gasoline and E85, and features a bypass valve set at 125.8 psi for demanding applications. Whether you are building an LS1 swap, tuning a turbocharged Subaru, or upgrading a high-horsepower UTV, this pump delivers consistent fuel pressure and flow.

OEM Replacement Made Better. KEMSO offers direct-fit replacement pumps for thousands of vehicles, from cars and trucks to motorcycles, ATVs, UTVs, and even personal watercraft. Their online fitment tool makes it easy to find the right pump for your specific year, make, and model. Unlike cheap aftermarket pumps, KEMSO units are engineered for superior flow and durability.

Lifetime Warranty. Every KEMSO fuel pump comes with a lifetime warranty, backed by a serialized body for tracking and peace of mind. This is a significant advantage over Aeromotive and other brands that offer only a 1-year or 2-year warranty. KEMSO stands behind its product for as long as you own the pump.

USA-Based Support. KEMSO offers technical support from USA-based technicians, making it easy to get help if you have questions during installation or operation. The company's support team is located in Houston, TX, and is ready to assist you.

Real-World Results. The LS swap community, drag racers, and off-road enthusiasts have reported excellent results with KEMSO pumps. One Colorado off-roader with an LS1-swapped Jeep put 30,000 miles on his KEMSO pump with zero issues, even at 12,000 feet elevation. Drag racers report smoother AFR readings and faster quarter-mile times after switching to KEMSO.

Affordable Pricing. Despite the high performance and lifetime warranty, KEMSO pumps are priced competitively. Many models are available for under $80, and their performance pumps are 30-40% cheaper than many premium brands while offering equal or better performance.

Final Thoughts

The Aeromotive in-tank fuel pump has been a solid choice for enthusiasts for years, but the market has evolved. Today, KEMSO offers a better value proposition: higher flow rates, lifetime warranty, USA-based support, and prices that are hard to beat. Whether you are replacing a failed pump or upgrading for better performance, KEMSO is a brand you can count on.

For the best selection of KEMSO fuel pumps for your vehicle, visit their official website at https://www.kemsoracing.com/. Their website features a vehicle lookup tool that covers over 4,000 models from 1990 to 2024, so finding the perfect pump for your ride is simple. Whether you need a replacement for a daily driver or a performance upgrade for a high-horsepower build, KEMSO has you covered with pumps backed by a lifetime warranty and USA-based support.