Upgrading to an external fuel pump system can be a game-changer for your vehicle’s performance, especially if you’re pushing your engine beyond factory specs. Whether you’re building a high-horsepower project car, optimizing for racing, or just tired of dealing with a weak in-tank pump, switching to an external setup offers reliability and power. Let’s break down how to tackle this upgrade step by step, keeping things simple and practical.
**Why Go External?**
First, understand why this upgrade matters. Factory fuel pumps are often designed for stock engines, and they’re tucked inside the fuel tank. While this keeps them quiet and cool, it also limits their flow capacity and makes repairs a hassle. An external pump, on the other hand, is easier to access, supports higher pressure for modified engines, and can handle increased fuel demands from turbochargers, superchargers, or aggressive tuning. Plus, many aftermarket external pumps are built to last, so you’re investing in long-term reliability.
**What You’ll Need**
Before diving in, gather your tools and parts. You’ll need an external fuel pump (matching your engine’s requirements), fuel lines rated for high pressure, fittings, a fuel filter, a mounting bracket, wiring connectors, and basic tools like wrenches, screwdrivers, and a multimeter. Don’t forget safety gear—gloves and goggles—because fuel systems are no joke. For those unsure about compatibility, brands like Kemso Racing offer pumps designed for various applications, making it easier to find the right fit.
**Step 1: Remove the Old Fuel Pump**
Start by relieving fuel system pressure. Locate the fuel pump fuse or relay in your vehicle’s fuse box, start the engine, and let it stall. This drains most of the pressure. Disconnect the battery for safety. Next, remove the access panel (if your car has one) to reach the in-tank pump. If not, you’ll need to drop the fuel tank—this is where having a helper or a jack stands comes in handy. Disconnect the fuel lines and electrical connections, then carefully pull out the old pump.
**Step 2: Prep for the New System**
With the old pump out, decide where to mount the external pump. Look for a spot close to the fuel tank but away from heat sources like exhaust components. The frame rail or a dedicated bracket near the tank works well. Make sure the pump is positioned below the tank to allow gravity to assist fuel flow. Secure it tightly using vibration-resistant mounts to minimize noise and wear.
**Step 3: Install the Fuel Lines and Filter**
Run new fuel lines from the tank to the pump and then to the engine. Use high-quality braided stainless steel or PTFE-lined hoses—they’re durable and resist heat degradation. Install an inline fuel filter between the tank and pump to catch debris. Avoid sharp bends in the lines, as they can restrict flow. Double-check all fittings with a wrench to prevent leaks.
**Step 4: Wire It Up**
Connect the pump to your vehicle’s electrical system. Most external pumps require a relay and fuse for proper operation. Tap into a switched power source (like the original fuel pump circuit) so the pump only runs when the engine is on. Use crimp connectors or solder the wires for a clean, reliable connection. Test the wiring with a multimeter before finalizing the setup.
**Step 5: Test for Leaks and Prime the System**
Before starting the engine, inspect every connection for leaks. Turn the ignition to “ON” (without cranking) to let the pump prime the system. Check again for leaks. If everything looks good, start the engine and let it idle. Listen for unusual noises from the pump, and monitor fuel pressure with a gauge if available. A healthy system should hold steady pressure without fluctuations.
**Final Tips**
– **Tune Your ECU**: If your engine has aftermarket modifications, update the ECU to match the new fuel delivery.
– **Maintenance**: Replace the fuel filter regularly and inspect lines for wear.
– **Safety**: Always disconnect the battery when working on fuel systems, and keep a fire extinguisher nearby.
Upgrading to an external fuel pump isn’t just about raw power—it’s about building a system that supports your goals without cutting corners. Take your time, follow these steps, and you’ll enjoy smoother performance and fewer headaches down the road. Got questions or tips from your own experience? Drop them in the comments below!