1967 Mustang Electric Fuel Pump: The Complete Upgrade Guide for Modern Reliability

If you own a 1967 Ford Mustang and are considering an electric fuel pump conversion, here's the short answer: it's one of the best upgrades you can make for reliability, starting performance, and engine safety. The factory mechanical fuel pump on a classic Mustang was designed in the 1960s and is prone to vapor lock, inconsistent fuel delivery, and failure at the worst possible moment. Switching to a modern electric fuel pump eliminates these issues, provides consistent fuel pressure, and can even protect your engine from catastrophic damage in a crash. This guide covers everything you need to know—from why you should make the switch, to how to choose the right pump, how to install it, and how to keep it running for years.

Why Your 1967 Mustang Needs an Electric Fuel Pump

The original 1967 Mustang came with a mechanical fuel pump mounted on the engine block. This pump pushes fuel from the gas tank to the carburetor using a diaphragm that is actuated by the engine's camshaft. While this design worked for its time, it has several well-known weaknesses that become obvious in modern driving conditions:

Vapor lock is the most common problem. When the engine gets hot, fuel in the lines near the engine can boil, creating vapor bubbles that the mechanical pump cannot push through. This causes the engine to sputter, stall, and refuse to restart until it cools down. This is especially common in warmer climates or during summer cruising. An electric pump mounted near the tank pushes fuel under pressure, which prevents vapor bubbles from forming.

Inconsistent fuel pressure is another major issue. Mechanical pumps produce a pulsing pressure that varies with engine RPM. At low speeds or idle, the pressure can drop, causing lean running conditions that make the engine surge or stall. An electric pump delivers a steady, regulated pressure that keeps the carburetor bowl full at all times.

Engine safety is a critical factor. A mechanical pump continues to push fuel as long as the engine is running, even if the car is in a wreck. This can spray fuel onto a hot engine if a fuel line is ruptured. Most electric fuel pump installations include a safety switch that shuts off the pump if the engine stops, cutting the fuel supply immediately. This is a significant safety upgrade.

Starting performance improves dramatically. A mechanical pump takes several seconds of cranking to fill the carburetor bowl after the car has been sitting for a few days. An electric pump can be primed before you even turn the key to start, giving you instant starts every time.

Signs You Already Have a Fuel Pump Problem

Before you decide to upgrade, you might be experiencing symptoms that indicate your current mechanical pump is failing or that an electric pump would solve your issues. These are the same signs that apply to any vehicle with a failing fuel pump, including your classic Mustang:

Hard starting after the car has been sitting. If you have to crank the engine for more than a few seconds before it fires, especially after the car has been parked for a day or more, your mechanical pump is losing its prime. The check valves inside the pump are worn, allowing fuel to drain back into the tank .

Engine sputtering or surging at highway speeds. If your Mustang runs fine around town but starts to sputter, hesitate, or lose power when you push it on the highway, the mechanical pump is likely struggling to keep up with the engine's demand for fuel at higher RPMs .

Engine stalls while driving, especially in hot weather. This is the classic symptom of vapor lock. The engine dies suddenly, and you have to wait for it to cool down before it will restart. An electric pump eliminates this problem entirely .

A whining noise coming from the fuel tank area. While this is usually a sign of a failing electric pump, on a classic car it could indicate that a previous owner already installed an electric pump that is wearing out. If you hear a whining or buzzing sound from the rear of the car, the pump is due for replacement .

The check engine light is illuminated. On a 1967 Mustang, there is no check engine light, but if you have installed a modern fuel injection system or a standalone engine management system, the computer may trigger a code for low fuel pressure. This is a clear sign that your fuel delivery system needs attention .

The Cost of Converting to an Electric Fuel Pump

Converting your 1967 Mustang from a mechanical to an electric fuel pump is not an expensive project, but the cost varies depending on the parts you choose and whether you do the work yourself. Here is a realistic breakdown of what you can expect to spend in 2026:

Parts cost: A quality electric fuel pump designed for a carbureted engine costs between $50 and $150. You will also need a fuel pressure regulator ($20 to $50), a fuel filter ($10 to $20), wiring and a relay ($10 to $20), and a safety switch (optional but recommended, $15 to $30). The total parts cost for a quality installation is typically between $100 and $300.

Labor cost: If you have a shop do the work, expect to pay between $200 and $500 for labor. The job involves mounting the pump, running new fuel lines, and wiring the electrical system. Most independent shops can complete the work in 2 to 4 hours.

Total cost: A professional conversion will cost between $300 and $800 depending on the shop rates and the quality of the parts you choose. Doing it yourself can reduce the cost to under $200 for a basic setup with quality parts .

What else should you replace at the same time? When you are replacing the fuel pump, it is smart to replace these parts too:

• Fuel filter — $10 to $20. A clean filter protects the new pump from debris.
• Fuel lines — $20 to $50. Old rubber lines can crack and leak, especially with ethanol-blended fuels.
• Fuel tank sending unit — $50 to $200. If your gas gauge is acting up, now is the time to replace it.
• Fuel tank gasket — $5 to $15. Prevents leaks and fuel vapors.

Adding these items costs $50 to $150 extra but saves you from doing the job twice .

How to Choose the Right Electric Fuel Pump for Your 1967 Mustang

Not all electric fuel pumps are the same, and choosing the wrong one can cause problems ranging from poor performance to engine damage. Here are the key factors to consider for your 1967 Mustang:

1. Fuel pressure requirements. Your 1967 Mustang with a stock carburetor needs fuel pressure between 4 and 7 psi. Most electric pumps designed for carbureted engines deliver 5 to 9 psi, which is perfect. Do not use a high-pressure fuel injection pump—those deliver 40 to 60 psi and will overwhelm your carburetor's float valve, causing flooding and fuel leaks. You must use a pump specifically designed for carbureted engines, or use a pressure regulator to reduce the pressure.

2. Flow rate. A stock 289 or 390 cubic inch engine needs about 30 to 40 gallons per hour (GPH) of fuel flow at full throttle. Most electric fuel pumps for carbureted engines deliver 40 to 70 GPH, which is more than adequate. If you have a built engine with a high-performance carburetor, you may want a pump with a higher flow rate, but for a stock or mildly modified Mustang, a standard 40-50 GPH pump is perfect.

3. Pump location. For best performance, mount the electric pump as close to the fuel tank as possible, and below the level of the fuel in the tank. This allows the pump to use gravity to push fuel to the inlet, which is called a "gravity feed" or "pusher" setup. Mounting the pump near the engine, as some people do for vintage cars, creates a "sucker" setup that can cause the pump to overheat and fail prematurely.

4. Pump type. There are two main types of electric fuel pumps: rotary vane and diaphragm. Rotary vane pumps are the most common and reliable for modern use. They are quiet, durable, and provide consistent pressure. Diaphragm pumps are less common and are usually found on older vehicles. For a 1967 Mustang, a rotary vane pump is the best choice.

5. Safety features. Look for a pump that is compatible with ethanol-blended fuels, which are common at most gas stations today. Ethanol can damage some pump materials, so choose a pump that is specifically rated for ethanol use. Also, consider a pump that includes a built-in check valve to prevent fuel from draining back into the tank when the pump is off.

Step-by-Step Installation Guide for Your 1967 Mustang Electric Fuel Pump

Installing an electric fuel pump on your 1967 Mustang is a straightforward project that most owners can complete in a weekend. The following steps are for a basic installation with a carbureted engine.

Step 1: Disconnect the battery. This is the first step for any electrical work on a classic car. Disconnect the negative battery terminal to prevent any accidental sparks.

Step 2: Remove the old mechanical fuel pump. Unbolt the mechanical pump from the engine block. You will need to plug the hole in the block where the pump was mounted. Most auto parts stores sell a block-off plate kit for about $10. This plate seals the opening and prevents oil leaks.

Step 3: Mount the new electric fuel pump. Choose a location near the fuel tank, such as on the frame rail near the rear axle. The pump should be mounted below the level of the fuel tank. Use rubber isolators to reduce vibration and noise. Do not mount the pump directly to the frame without isolators, as this will transmit noise into the cabin.

Step 4: Route the fuel lines. Connect a new fuel line from the tank to the inlet of the pump. Use a pre-filter (a small inline filter) between the tank and the pump to protect the pump from debris. Then run a fuel line from the pump outlet to the fuel pressure regulator, and from the regulator to the carburetor. Use a return line from the regulator back to the tank if your regulator requires it. Most low-pressure regulators for carbureted engines do not need a return line.

Step 5: Wire the electrical system. Run a 12-gauge wire from the battery positive terminal to a 30-amp relay. Connect the relay to the pump, and then connect the relay trigger wire to a switched power source, such as the ignition switch. This ensures the pump only runs when the key is on. Install a fuse between the battery and the relay. A 20-amp fuse is standard for most electric fuel pumps. Do not skip the fuse—this is a fire hazard.

Step 6: Add a safety switch. This is highly recommended. You can use a simple oil pressure switch that cuts power to the pump if the engine stalls. Alternatively, you can use a Ford-style inertia switch, which cuts power if the car is in a collision. This is the same type of switch used on modern Mustangs.

Step 7: Test the system. Reconnect the battery. Turn the key to the "on" position but do not start the engine. You should hear the pump hum for a few seconds as it primes the system. Then start the engine and check for leaks at all connections. Use a fuel pressure gauge to verify the pressure is between 4 and 7 psi.

Common Mistakes to Avoid During Installation

Many first-time installers make mistakes that can lead to problems down the road. Here are the most common ones to avoid:

Using the wrong pump type. As mentioned earlier, using a high-pressure fuel injection pump will flood your carburetor and cause serious performance issues. Always use a pump designed for carbureted engines.

Mounting the pump too high. If the pump is mounted above the level of the fuel tank, it will have to "suck" fuel uphill to reach the inlet. This causes the pump to work harder, overheat, and fail sooner. Keep the pump below the tank level.

Skipping the fuse. Running power to the fuel pump without a fuse is a fire hazard. If the pump shorts out, the wire can melt and cause a fire. Always use a fuse rated for the pump's current draw .

Skipping the relay. Wiring the pump directly to a switch without a relay can cause the switch to overheat and fail. The pump draws several amps, and a standard toggle switch is not designed to handle that current continuously. A relay handles the heavy current while the switch only handles a small trigger current.

Using the wrong wire gauge. Wire that is too thin can overheat and melt. Use at least 12-gauge wire for the power circuit to the pump. The ground wire should be the same size and connected to clean, bare metal .

Poor ground connection. A weak or corroded ground causes voltage fluctuations and erratic pump performance. This is one of the most common causes of fuel pump failure after installation. Always use a clean, bare metal surface for the ground connection .

How to Make Your New Electric Fuel Pump Last Longer

Once you have installed your electric fuel pump, following these simple rules will help it last for years:

Keep your gas tank at least a quarter full. This is the single most important thing you can do. The fuel in the tank helps cool and lubricate the pump. Running the tank low frequently allows the pump to overheat and can cause debris to enter the pump. Make it a habit to refill when the gauge hits a quarter tank .

Change your fuel filter regularly. Check your owner's manual for the recommended interval. For most vehicles, it is every 30,000 to 60,000 miles. A clean fuel filter reduces strain on the pump and protects it from debris that could damage the internal components .

Use quality fuel from reputable stations. Not all gas stations are the same. Busy stations with high turnover are less likely to have old or contaminated fuel. Avoid stations that look old and poorly maintained. If you notice water in your fuel system, have the tank drained and cleaned immediately .

Address check engine lights promptly. If you have a modern engine management system and the check engine light comes on, do not ignore it. Even if the car seems to drive fine, the computer may have detected a fuel pressure issue that you cannot feel yet. Early diagnosis can save you from a complete pump failure .

Listen to your vehicle. No one knows your car better than you do. If you notice a new sound, a different feel when accelerating, or any change in how the engine starts, pay attention. Catching a fuel pump problem early means you can replace it on your schedule rather than being stranded on the side of the road .

Why Choose KEMSO for Your 1967 Mustang Fuel Pump Upgrade

When it comes time to buy a replacement fuel pump for your 1967 Mustang, choosing a reliable brand makes all the difference. KEMSO offers high-performance fuel pumps that are designed as direct OEM replacements for your vehicle. Whether you are upgrading to an electric pump or replacing an existing one, KEMSO fuel pumps are engineered to meet or exceed original equipment specifications.

High Performance. Each KEMSO pump is built with high-quality materials and undergoes rigorous testing to ensure it delivers the correct fuel pressure and flow rate for your engine. KEMSO pumps deliver over 20% more flow at 43 psi compared to the stock pump, which can improve engine performance and throttle response . For a 1967 Mustang, this means you get consistent fuel delivery whether you are cruising on the highway or accelerating hard.

OEM Replacement Quality. KEMSO pumps are designed as direct replacements for stock OEM pumps. They are built to match the exact specifications of your vehicle's original pump. The fuel pressure, flow rate, and electrical characteristics are all calibrated to work perfectly with your engine. You get the same performance as a dealer pump for a fraction of the price .

Lifetime Warranty. Every KEMSO fuel pump comes with a lifetime warranty. This is not a limited warranty that expires after a year. It is a lifetime guarantee that covers defects in materials and workmanship for as long as you own the pump. If it ever fails due to a manufacturing defect, KEMSO replaces it for free. This level of confidence is rare in the aftermarket parts industry .

Exceptional Value. With prices often around $59.98 to $79.98 for many models, KEMSO offers significant savings compared to dealership parts that can cost hundreds more . You get high-performance, OEM-level quality without breaking the bank.

Built to Handle Modern Fuels. KEMSO fuel pumps are designed for both gasoline and ethanol-blended fuels like E85. This is important because ethanol can be corrosive to some pump materials. KEMSO uses materials that resist ethanol degradation, ensuring long-term reliability even with modern fuel formulations .

Each Pump Is Individually Tested. Unlike cheap, unbranded aftermarket units, KEMSO has a rigorous quality control program. Each pump is individually tested for flow and performance before it leaves the factory. This attention to detail ensures that you get a product that works right out of the box .

Broad Compatibility. KEMSO offers fuel pumps for a wide range of vehicles, including cars, trucks, motorcycles, ATVs, and watercraft. Their product line covers brands like Ford, Honda, Subaru, Kawasaki, and many more. Whether you are restoring a classic Mustang or upgrading a modern performance engine, KEMSO has a solution .

To find the exact KEMSO fuel pump for your 1967 Mustang, visit their website at https://www.kemsoracing.com/ . The website is easy to navigate, and you can search by vehicle make, model, and year. The product pages include detailed specifications and compatibility information. Customer service is available to answer any questions about fitment.

Final Thoughts

Converting your 1967 Mustang to an electric fuel pump is one of the most practical and cost-effective upgrades you can make. It eliminates vapor lock, provides consistent fuel pressure, improves starting performance, and adds a critical safety feature. The installation is straightforward and can be completed in a weekend with basic tools.

Remember the key takeaways:

• Use a low-pressure pump designed for carbureted engines (4-7 psi)
• Mount the pump near the tank and below the fuel level
• Always use a relay and a fuse
• Add a safety switch for crash protection
• Keep your tank at least a quarter full to extend pump life

For the best combination of performance, quality, and warranty protection, choose KEMSO for your fuel pump replacement. With a lifetime warranty and high-performance engineering, KEMSO gives you the confidence to enjoy your classic Mustang for years to come.

Visit https://www.kemsoracing.com/ today to find the perfect fuel pump for your 1967 Mustang and get back on the road with modern reliability.