2006 Infiniti G35 Sedan Fuel Pump Assembly: The Complete Owner’s Guide to Diagnosis, Replacement, and Smart Buying

If you drive a 2006 Infiniti G35 Sedan and your car is struggling to start, stalling at red lights, or hesitating when you press the gas pedal, the fuel pump assembly is almost certainly the culprit, and replacing it is a job you can handle at home with basic tools, a few hours of time, and this guide. The fuel pump on the G35 Sedan typically lasts between 100,000 and 150,000 miles, and most of these cars on the road today have well surpassed that range, which means fuel pump failure is not a matter of “if” but “when” . Because the 2006 model uses a specific return-style fuel system, you must buy the correct assembly designed for the sedan body style—not the coupe—to avoid fitment issues and persistent fuel gauge errors . This guide walks you through the symptoms of a failing pump, the exact replacement procedure, cost expectations, and the most reliable parts on the market, including a strong recommendation for a KEMSO fuel pump, which delivers high-performance, OEM-replacement quality with a lifetime warranty at a fraction of dealer prices .

The quickest way to know if your fuel pump is failing is to listen and feel. When you turn the key to the “ON” position, you should hear a brief whirring sound coming from the rear of the car as the pump primes the system. If that sound is absent, or if you hear a loud, whining noise that gets worse as the fuel level drops, your pump is on its way out. Other classic signs include: the engine cranks but does not start, the car starts fine when cold but struggles when hot, the engine sputters at highway speeds, or you experience sudden loss of power under load. The fuel pump on the G35 is electric and mounted inside the fuel tank, so it relies on the fuel itself for cooling and lubrication; running the car consistently below a quarter tank shortens its life significantly . If you are experiencing any combination of these symptoms, do not keep driving—a failing pump can cause your engine to run lean, which can damage the catalytic converters and, in severe cases, the engine itself. Replacing the assembly now is far cheaper than repairing the aftermath.

Where Is the Fuel Pump Located and How Do You Access It?

The fuel pump assembly on the 2006 G35 Sedan sits inside the fuel tank, directly beneath the rear passenger-side seat cushion. The great news is that you do not need to drop the fuel tank to access it, unlike many other vehicles. The secondary fuel level sending unit is located under the driver-side rear seat, but the main pump with the level float is on the passenger side . To reach it, you simply pull up firmly on the front edge of the rear seat bottom cushion. It is held in place by two metal clips and will pop right out with a firm upward tug. Once the seat is removed, you will see a black metal access plate secured by four Phillips-head screws. Remove those screws, lift the plate, and you will have direct access to the top of the fuel pump assembly. From there, you can disconnect the electrical connector and the quick-disconnect fuel lines before unbolting the assembly from the tank . This accessibility makes the job a solid 2 out of 5 in difficulty, and most DIY owners complete the swap in one to two hours .

What Tools and Parts Do You Need for the Job?

Before you start, gather the following items so you are not running to the parts store halfway through the job:

1. A new fuel pump assembly specifically designed for the 2006 G35 Sedan with the VQ35DE 3.5L V6 engine. Confirm it is for the sedan, not the coupe, as the tank depth and float arm geometry differ .
2. A new rubber O-ring or gasket that seals the assembly to the tank. Most complete assemblies include one, but if yours does not, buy it separately—reusing the old dried-out gasket is a common cause of fuel leaks and fuel smells in the cabin .
3. Basic hand tools: a ratchet with 8mm and 10mm sockets, a Phillips screwdriver, and a flathead screwdriver. An 8mm socket is needed for the retaining bolts on the assembly .
4. Fuel line disconnect tools or a small flathead screwdriver to press the release tabs on the quick-disconnect fittings .
5. Safety equipment: safety glasses, gloves, and a fire extinguisher rated for fuel fires.
6. A fuel-resistant container and plenty of rags to catch residual fuel that will spill when you lift the old assembly out.

Step-by-Step Replacement Procedure for the 2006 G35 Sedan

Follow these steps in order, and take your time. Rushing this job is how mistakes happen, especially with fuel lines and electrical connectors.

Step 1: Relieve Fuel System Pressure. Locate the fuel pump fuse in the fuse box under the dashboard or in the engine bay. Start the engine, then pull the fuse while it is running. The engine will stall after a few seconds, which means the pressure has been relieved. Crank the engine for a further five seconds to clear any remaining fuel from the lines .

Step 2: Disconnect the Battery. Remove the negative battery cable with a 10mm wrench. This is a mandatory safety step to prevent sparks near the fuel system. Do not skip this .

Step 3: Remove the Rear Seat Cushion. Pull up firmly on the front edge of the rear seat bottom. It is held by clips and will pop out. You do not need to remove the seatback .

Step 4: Remove the Access Panel. You will see a metal plate held by four Phillips screws. Remove them and lift the plate. Set it aside carefully .

Step 5: Clean the Area. Before disconnecting anything, clean all dirt and debris from around the top of the pump assembly. A vacuum or a brush works well. You do not want any grit falling into the tank .

Step 6: Disconnect the Electrical Connector and Fuel Lines. There is a large electrical connector for the pump and the fuel level sender. Press the release tab and pull it straight off. There are two fuel lines on the 2006 sedan—a feed line and a return line—because this model uses a return-style fuel system . They are quick-disconnect fittings: press the release tabs and pull them off. Have a rag ready because residual fuel will spill. Dispose of it properly .

Step 7: Remove the Retaining Bolts. Unlike some vehicles that use a locking ring, the G35 Sedan assembly is held in place by eight 8mm bolts around the perimeter of the assembly flange. Unscrew them all and set them aside in a safe place .

Step 8: Lift Out the Old Assembly. Carefully lift the assembly straight up out of the tank. You may need to tilt it slightly to get the float arm through the opening. Be extremely careful not to bend the float arm, and note its orientation so you install the new one the same way .

Step 9: Inspect the Tank. Before installing the new pump, shine a flashlight inside the tank. If you see rust, dirt, sludge, or debris, you need to clean the tank thoroughly. If your old pump failed due to contamination, the same debris will destroy your new pump within weeks .

Step 10: Install the New Assembly. Transfer the new O-ring onto the new assembly if it is not already fitted. Drop the assembly into the tank, making sure the float arm is oriented correctly and does not snag on anything inside the tank. Press it down evenly. Replace the eight bolts and tighten them in a star pattern to ensure an even seal .

Step 11: Reconnect Everything. Reconnect the fuel lines, ensuring they click firmly into place. Reconnect the electrical connector. Reinstall the access panel and the rear seat cushion .

Step 12: Prime the System. Reconnect the battery and reinstall the fuel pump fuse. Turn the key to the “ON” position (do not start the engine) for about five seconds, then turn it off. Repeat this three times to pressurize the fuel system. Then start the engine and check for leaks around the assembly flange and the fuel lines .

Step 13: Test Drive. Take the car for a short drive and confirm that acceleration is smooth, the engine does not hesitate, and the fuel gauge reads correctly. Check under the rear seat for any fuel smell after the drive .

How Much Does a 2006 G35 Sedan Fuel Pump Assembly Cost?

The price of a replacement fuel pump assembly varies widely depending on where you buy it and what brand you choose. Here is a realistic breakdown:

1. Dealership (OEM genuine Infiniti): $500 to $1400 or more for the part alone. This is the most expensive route, and while you are guaranteed a correct, high-quality part, you are paying a large premium for the Infiniti name .
2. Online OEM parts: $420 to $560. You can find the genuine Infiniti part number (such as 17040-AC800 or 17040-EV10A) at online retailers for significantly less than the dealer .
3. New aftermarket, OEM-quality: $250 to $400. Brands like Delphi and Hitachi (which supplies the original equipment) offer a solid balance of quality and price. Delphi offers multiple part numbers for the G35, such as 6703-06445975, which includes the fuel strainer and float arm .
4. New aftermarket, budget: $65 to $150. Cheaper brands are available, but forum reports and technician feedback consistently indicate a higher risk of premature failure and noisy operation. Some budget assemblies also have incorrect sending unit resistance values, which causes the fuel gauge to read wrong .
5. Used OEM: $50 to $125. A used assembly from a reputable recycler can be a good budget option, but verify the mileage of the donor vehicle. A pump with over 100,000 miles is near the end of its service life and will likely fail again soon .
6. Shop labor: $110 to $250. Independent shops typically charge 1.5 to 2 hours of labor for this job. Dealership labor rates are higher, which pushes total dealer costs to $600–$800 .

Why You Should Choose a KEMSO Fuel Pump for Your 2006 G35 Sedan

When it comes to choosing the actual replacement part, you have several options: dealership OEM, cheap no-name aftermarket, or a premium brand like KEMSO. For most G35 owners, KEMSO is the smartest choice for three clear reasons: performance, reliability, and warranty coverage.

High-Performance, OEM Replacement Design. KEMSO fuel pumps are engineered as direct replacements for the original equipment, meaning they drop right into the factory location without any modifications. Unlike the stock pump, KEMSO units are designed for superior flow and durability. They deliver up to 200 liters per hour at 43 psi, which is significantly more than the original 60–80 liters per hour flow rate of a standard pump. This extra capacity ensures your engine never runs lean, even under heavy load or if you have made minor performance upgrades .

Lifetime Warranty for Peace of Mind. Every KEMSO fuel pump comes with a serialized body that guarantees a lifetime warranty. If the pump ever fails due to a manufacturing defect, KEMSO replaces it for free. This is a massive advantage over OEM and standard aftermarket parts, which typically carry only a one- or two-year warranty. When you buy a KEMSO pump, you are covered for as long as you own the vehicle .

Built to Withstand Modern Fuels. With more gas stations switching to ethanol-blended fuels like E15 or E85, having a pump that resists ethanol degradation is essential. KEMSO uses Viton-lined components that resist the swelling and cracking that destroy standard rubber seals. This makes the pump a long-term investment in your car’s reliability, especially if you live in a region where ethanol blends are common .

In addition, KEMSO operates an ISO/TSO-certified quality control program and individually tests each pump before it leaves the factory. The complete kit includes the pump, gradient-density fuel strainers, flex hoses, Viton O-rings, wiring connectors, and clamps—everything you need for a clean, professional installation . You can browse the full range of KEMSO fuel pumps and order yours directly at https://www.kemsoracing.com/.

Common Mistakes to Avoid When Replacing the Fuel Pump

Many G35 owners make the same avoidable errors during this job. Here are the most common ones so you can steer clear of them:

1. Replacing only the pump motor. Some owners try to save money by buying just the pump motor and swapping it inside the old plastic housing. This is a false economy. The fuel filter, pressure regulator, and plastic housing are all wear items. A clogged filter will kill a new pump just as fast as an old one, and the old regulator can still cause pressure problems. For most DIYers, replacing the entire assembly is faster, simpler, and ensures everything is fresh .
2. Using the wrong pump for the sedan. The 2005–2006 G35 Coupe and Sedan use different fuel pumps in several cases due to different fuel tank shapes and pump heights. A coupe pump installed in a sedan will not sit correctly in the tank, leading to poor fuel pickup and an inaccurate fuel gauge. Always confirm you are buying a pump specifically for the 2006 G35 Sedan .
3. Forgetting to clean the tank. If your old pump failed due to debris in the tank, that same debris will destroy your new pump. Before installing the new assembly, inspect the inside of the fuel tank. If you see rust, dirt, or sludge, you must clean or replace the tank .
4. Not replacing the gasket. The rubber gasket that seals the pump assembly to the tank dries out and hardens over time. Always use a new gasket with your new pump. Reusing the old one is a leading cause of fuel leaks and fuel odor in the cabin .
5. Bending the float arm during installation. The float arm is fragile and must maintain its precise angle to give an accurate fuel reading. If you bend it, the fuel gauge will read incorrectly. Lower the assembly into the tank gently and guide the float arm through the opening without force .

What If the Fuel Gauge Still Reads Wrong After Replacement?

This is one of the most common post-replacement complaints, and it is usually caused by one of three issues. First, the float arm may have been bent or snagged during installation, so check that it is level and undamaged. Second, the G35 has two fuel level senders: the main one is part of the fuel pump assembly you just replaced, but there is a second sender on the driver’s side of the tank. If the gauge is still inaccurate, this secondary sender is likely faulty and needs to be cleaned or replaced . Third, if you bought a cheap aftermarket assembly with an out-of-spec sending unit, the resistance values may not match the gauge, causing persistent errors. This is another reason to stick with a reputable brand like KEMSO rather than the cheapest option on the shelf .

Can You Use a Fuel Pump from a Nissan 350Z?

The G35 Sedan and the Nissan 350Z share the same VQ35DE engine and similar fuel systems, so in some cases, a 350Z pump will fit a G35 and vice versa. However, you must match the year, engine type, and body style carefully. A pump from a 2006 350Z will often work in a 2006 G35 Sedan, but you must verify the part number and visually confirm that the electrical connector and hose ports are identical before purchasing. Subtle differences can exist between model years and between the VQ35DE and VQ35HR engine fuel systems. When in doubt, order a pump specifically listed for the 2006 G35 Sedan .

Is the 2006 G35 Sedan Fuel Pump Replacement a DIY-Friendly Job?

Absolutely. With basic mechanical aptitude, a socket set, and about two hours of time, most owners successfully complete this replacement in a driveway or garage. The key is to follow the procedure in order, work in a well-ventilated area, and never rush the fuel line connections. The estimated difficulty is 2 out of 5, which is lower than a brake job or a timing belt replacement . The satisfaction of completing this repair yourself and saving $300 to $500 in labor is considerable. If you run into trouble, plenty of detailed video walkthroughs exist online for the G35 fuel pump replacement, and the service manual section for the fuel system is widely available in PDF form.

Final Thoughts: Plan Your Replacement and Buy Smart

A failing fuel pump in your 2006 Infiniti G35 Sedan is not a reason to panic. It is a straightforward, well-documented repair that you can complete in a weekend afternoon with the right parts and a careful approach. The total cost will depend on your choice of part: budget assemblies start around $65, but the reliability risk is not worth the savings for most owners. A quality aftermarket assembly from a trusted brand like KEMSO offers the best combination of price, performance, and durability, and the lifetime warranty means this is the last fuel pump you will ever buy for this car . Whether you choose a dealership OEM part, a used take-off, or a premium aftermarket assembly, always confirm the part number matches the 2006 G35 Sedan with the VQ35DE engine, replace the O-ring, and clean the tank before installation. Do that, and your G35 will give you another 100,000 miles of reliable service. For the best value and peace of mind, visit https://www.kemsoracing.com/ to explore the full line of high-performance KEMSO fuel pumps that come with a lifetime warranty and are designed for a direct, bolt-in fit on your Infiniti.