Understanding and Using Facet Electric Fuel Pumps for Reliable Engine Performance

A Facet electric fuel pump is a dependable and often cost-effective solution for delivering gasoline from your vehicle's tank to the carburetor or fuel injection system. Properly selected, installed, and maintained, a Facet pump provides consistent fuel pressure and flow, ensuring your engine runs smoothly and efficiently. This guide explains what these pumps are, how they work, their advantages, and how to choose, install, troubleshoot, and replace one effectively.

What is a Facet Electric Fuel Pump?

Facet Electric Fuel Pumps are positive displacement fuel pumps manufactured by Facet (also known as Purolator Facet in some regions). They are widely used in various automotive applications, particularly in classic cars, hot rods, boats, motorcycles, ATVs, industrial machinery, generators, and small aircraft that utilize carburetors or some types of low-pressure electronic fuel injection systems. Unlike mechanical fuel pumps driven by the engine's camshaft, Facet pumps use an electric motor powered by the vehicle's electrical system to pump fuel. Common Facet designs include the cylindrical "Canister" style pumps (like the iconic 40177) and the cube-shaped "Box" style pumps (like the 476108E).

How Does a Facet Electric Fuel Pump Work?

The operation of a Facet electric fuel pump is relatively straightforward:

  1. Electrical Activation: When the ignition key is turned on, power is sent to the fuel pump relay (or directly to the pump in simpler systems), energizing the pump's internal electric motor.
  2. Pumping Mechanism: The motor drives a positive displacement mechanism. In canister pumps, this is typically a piston reciprocating inside a cylinder. In cube pumps, it's often a diaphragm mechanism.
  3. Fuel Intake: As the piston retracts or the diaphragm moves outward, it creates a partial vacuum in the pump chamber. This low pressure draws fuel from the tank through the inlet port via the fuel supply line.
  4. Fuel Discharge: As the piston moves forward or the diaphragm moves inward, it pressurizes the fuel in the chamber. This pressure forces the fuel out through the pump's outlet port and into the fuel line heading towards the engine.
  5. Check Valves: Internal check valves (one at the inlet, one at the outlet) ensure fuel flows only in one direction: from the tank to the engine, preventing backflow.
  6. Pulsing Output: Due to the reciprocating nature of the pumping element, Facet pumps deliver fuel in distinct pulses. This pulsing action can often be heard and felt as a distinct buzzing or tapping sound when the pump is operating.

Key Advantages of Facet Electric Fuel Pumps

Facet pumps are popular for several reasons:

  • Reliability and Durability: They are known for robust construction and long service life when used within their specifications.
  • Self-Priming: Facet pumps excel at self-priming, meaning they can lift fuel from a tank located below the pump itself, overcoming significant suction head. This is a major advantage over some other pump types.
  • Mounting Flexibility: Their compact size and design allow for relatively easy mounting in various locations under the hood or near the tank.
  • Wide Availability and Affordability: Facet pumps are readily available from numerous auto parts retailers and are generally more affordable than many other electric fuel pump brands.
  • Simplicity: Their design is mechanically simple, contributing to reliability and ease of understanding.
  • Wide Application Range: Facet offers numerous models designed for specific flow rates, pressure outputs, voltages (6V, 12V, 24V), and fuel types (gasoline, diesel), catering to a vast array of vehicles and machinery.

Common Applications for Facet Fuel Pumps

You'll commonly find Facet pumps used in:

  • Carbureted Engines: Replacing worn-out mechanical pumps or providing fuel where no mechanical pump provision exists (common in engine swaps). Facet pumps provide the low pressure (typically 2.5 - 4.5 PSI) needed by carburetors.
  • Early Fuel Injection: Powering throttle body injection (TBI) systems or some multi-port injection systems requiring moderate pressures (e.g., 12-15 PSI).
  • Diesel Engines: Specific Facet models are designed as lift pumps for diesel applications, feeding fuel to high-pressure injection pumps.
  • Fuel Transfer: Used for transferring fuel between containers or tanks.
  • Auxiliary Systems: Powering auxiliary generators or equipment requiring fuel delivery.
  • Small Aircraft: Commonly used in experimental and light sport aircraft where their reliability is valued.

Choosing the Right Facet Fuel Pump Model

Selecting the correct pump model is critical for performance and longevity. Key factors to consider:

  1. Engine Fuel Demand (Flow Rate): Determine the flow rate required by your engine (measured in Gallons per Hour - GPH or Liters per Hour - LPH). This depends on engine horsepower and application.
    • Too Little Flow: Engine starves for fuel at higher RPMs or under load.
    • Too Much Flow: While not inherently damaging if pressure is regulated, it wastes energy and puts unnecessary strain on the pump. Excess flow is typically bypassed back to the tank via a return line or pressure regulator.
  2. Required Pressure (PSI/Bar): Carburetors need low pressure (typically 3-5 PSI). Electronic fuel injection systems vary widely (TBI: 9-15 PSI, Multi-port: usually significantly higher, though Facet pumps are generally not suitable for high-pressure EFI). Ensure the pump's maximum pressure output matches or slightly exceeds your system's requirement. Use a pressure regulator to dial it down precisely. Common Facet PSI ratings include 4 PSI (for carbs), 4-7 PSI, 6-9 PSI, 9-12 PSI, and 12-15 PSI.
  3. Voltage: Match the pump's voltage (12V, 6V, 24V) to your vehicle's electrical system. Using a 12V pump on a 6V system will result in poor performance. Using a 6V pump on a 12V system will quickly destroy it.
  4. Fuel Type: Use gasoline-rated pumps for gasoline and diesel-rated pumps (e.g., Facet Cylinder pumps) for diesel fuel. The internal seals and materials differ.
  5. Flow Direction: Some Facet pumps (especially box styles) are uni-directional. The inlet and outlet ports must be connected correctly (clearly marked). Canister pumps are generally bi-directional.
  6. Mounting Position: Some pumps can be mounted in any orientation, while others require a specific orientation (like vertical). Check the specifications for your chosen model (e.g., many canister pumps must be mounted vertically with outlets pointing up).
  7. Connector Type: Ensure the pump's electrical connection (spade terminals, wires, grommet) is compatible with your wiring.

Installation Guidelines for Facet Electric Pumps

Installing a Facet electric fuel pump correctly is essential for safety and reliability.

  1. Location: The ideal location is close to the fuel tank and as low as possible, preferably lower than the bottom of the tank. This minimizes the suction lift the pump must overcome. Avoid mounting where exposed to excessive heat (exhaust manifolds) or debris. Many installers mount them on the frame rail near the tank.
  2. Mounting: Use the provided rubber insulators or grommets when mounting the pump. These dampen vibration and noise, protect the pump casing from chafing, and electrically isolate it from the chassis. Mount securely to prevent fatigue from engine vibration.
  3. Wiring: Use an adequately sized wire gauge. Route wiring away from heat and sharp edges. Incorporate a safety Inertia Safety Switch or Oil Pressure Safety Switch into the power circuit. This is a critical safety feature.
    • Inertia Switch: Opens the pump circuit in the event of a collision, preventing fuel from pumping after an accident.
    • Oil Pressure Switch: Only allows the pump to run if the engine has oil pressure, preventing it from pumping fuel if the engine stalls. Often used in conjunction with a momentary prime circuit.
    • Always use a fuse appropriate for the pump's amperage draw.
  4. Fuel Lines: Use appropriate fuel-rated hose for both inlet and outlet sides. Ensure hose clamps are rated for fuel injection (FI clamps provide better sealing at all pressures) and are properly tightened.
    • Connect the pump's inlet port to the line coming from the fuel tank.
    • Connect the pump's outlet port to the line leading to the fuel filter and then the engine (carb or injector).
  5. Filtration: Install a good quality pre-pump filter (sock filter in the tank or inline filter before the pump) to protect the pump from large contaminants. Install a post-pump filter (main fuel filter) before the carburetor or fuel injectors to catch smaller particles.
  6. Pressure Regulation: If your pump outputs higher pressure than your system requires (it usually does), you must install a fuel pressure regulator after the pump and before the carburetor or injection system. Set the regulator to the manufacturer's specification for your carb or injector.

Troubleshooting Common Facet Pump Issues

Even reliable pumps can encounter problems. Here's how to diagnose common issues:

  1. Pump Doesn't Run / No Noise:
    • Check ignition power and fuse. Use a test light or multimeter.
    • Verify inertia switch or oil pressure switch hasn't tripped (reset if possible). Check switch operation.
    • Check ground connection is clean and secure.
    • Test pump directly: Apply correct voltage (+12V) to the pump's positive terminal and ground the negative terminal (momentarily!). If it runs, the issue is wiring or safety switches. If not, the pump motor is likely faulty.
  2. Pump Runs but No/Low Fuel Pressure:
    • Check for fuel leaks on suction side (inlet hose, tank pickup). Leaks here introduce air and prevent priming.
    • Clogged pre-pump filter or tank pickup.
    • Tank vent blocked, causing vapor lock.
    • Wrong pump direction (verify inlet/outlet ports connected correctly - common with box pumps).
    • Excessively long inlet hose or too many bends creating suction resistance.
    • Failed check valve inside pump. Pump runs but no flow or pressure.
    • Weak pump motor (less common if new).
  3. Pump Runs Loudly or Excessively Hot:
    • Running Dry: This is the most common cause of noise and heat. It destroys pump internals quickly. Ensure pump always has a fuel supply. Check for plugged inlet or leak on suction side.
    • Incorrect voltage (too high).
    • Exceeding maximum pressure capability (too much back pressure). Check for kinked outlet hose or faulty/clogged pressure regulator. Ensure return line (if present) isn't blocked.
    • Poor mounting (vibration transmitted to chassis).
    • End of service life (internal wear).
  4. Inconsistent Engine Performance (Surging, Stalling):
    • Intermittent pump operation (check wiring connections, failing relay, tripping safety switch).
    • Pump unable to maintain adequate flow (undersized pump, clogged filter, restricted line).
    • Incorrect fuel pressure (faulty regulator).
    • Vapor lock due to heat or poor tank venting.

Maintenance and Maximizing Facet Pump Life

With simple care, a Facet pump can last many years:

  • Regular Filter Replacement: Change pre-pump and post-pump filters according to schedule. A clogged filter forces the pump to work harder.
  • Avoid Running Dry: Never operate the pump without fuel. Running dry causes instant damage to pump internals and motor.
  • Clean Connections: Periodically check electrical connections for corrosion and tightness.
  • Secure Mounting: Ensure mounting hardware and insulators are intact and secure. Vibration is a major cause of long-term fatigue failure.
  • Use Correct Fuel: Avoid contaminated fuel or fuels not specified for your pump model (like alcohol blends if not rated, especially in older pumps).
  • Monitor Operation: Listen for normal operation noise. Sudden changes in noise level (louder, quieter, different pitch) or excessive heat indicate a problem requiring investigation.

Replacing a Faulty Facet Pump

If diagnosis points to a failed pump, replacement is straightforward:

  1. Disconnect the negative battery terminal.
  2. Safely depressurize the fuel system (run engine until it stalls or clamp/plug hoses after disconnection).
  3. Disconnect inlet and outlet fuel lines (plug them immediately to minimize spillage).
  4. Disconnect electrical connectors.
  5. Unbolt the pump from its mount.
  6. Install the new pump: Mount it securely using isolators. Reconnect electrical and fuel lines correctly. Double-check inlet/outlet connections.
  7. Prime Carefully: Turn the key to "On" (without cranking) momentarily. Listen for the pump to prime (fill the lines and build pressure). Do this 2-3 times for 2-3 seconds each.
  8. Check carefully for fuel leaks at all connections before starting the engine.

Safety First When Working with Fuel Pumps

Fuel systems are inherently dangerous. Always prioritize safety:

  • Work in a Well-Ventilated Area: Gasoline vapors are highly flammable and explosive.
  • No Sparks or Flames: Strictly prohibit smoking, open flames, or anything creating sparks anywhere near the work area. Disconnect battery ground before starting work.
  • Use Correct Tools: Ensure all tools are in good condition.
  • Control Spills: Have a fire extinguisher rated for gasoline fires (Class B) readily available. Use absorbent pads. Never work with fuel near carpet or upholstery.
  • Relieve Fuel Pressure: Do this before disconnecting any fuel lines.
  • Minimize Skin Contact: Wear gloves. Gasoline is a health hazard.
  • Double-Check Connections: After installation, inspect all connections meticulously for leaks before turning on the pump or starting the engine.

Informed Choices: OEM vs. Aftermarket

Facet pumps are widely available as:

  • OEM Replacement: Sourced through major retailers or vehicle manufacturers' networks.
  • Aftermarket: Sold by numerous reputable parts suppliers. Stick with known brands like Facet or their direct replacements.

Facet often supplies pumps to major auto manufacturers as original equipment (especially box style pumps). Aftermarket replacements are generally reliable. Ensure you are purchasing the exact model number specified for your application to get the correct flow, pressure, and connection specifications.

Why Facet Remains a Top Choice

For applications requiring a dependable, self-priming, moderately priced electric fuel pump, Facet pumps have proven their worth over decades. Their simplicity, wide availability, variety of models for different demands, and reputation for longevity (when properly selected and installed) make them a go-to solution for mechanics and enthusiasts restoring classics, building custom vehicles, or maintaining equipment that needs reliable fuel delivery. By understanding how they work, choosing the correct model, installing them safely with essential shut-off protection, and performing basic maintenance, you can harness the reliability of a Facet electric fuel pump to keep your engine running at its best.

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