Here's a general overview of the process and considerations, but this is NOT a substitute for consulting your vehicle's wiring diagram and the instructions for your specific fuel pump:
1. Determine Your Fuel System Type:
* Return Style: Fuel flows from the tank to the engine, and excess fuel is returned to the tank. This is easier to add a second pump to.
* Returnless Style: Fuel flows from the tank to the engine only. The pump is precisely controlled to deliver only the fuel needed. Adding a second pump here is much more complex and often requires a fuel pressure regulator and sophisticated control system.
2. Identify Power and Ground Sources:
* Power: You'll need a switched power source (only on when the ignition is on) and potentially a relay to handle the pump's current draw. The switched power source could be tapped into an existing fuel pump circuit or another suitable location. Using an existing circuit might overload it if it isn't designed for the extra load.
* Ground: A solid ground connection to the vehicle's chassis is crucial.
3. Consider Fuel Pressure and Regulation:
* High Pressure: Adding a second pump significantly increases fuel pressure. You may need a fuel pressure regulator to control the pressure delivered to the engine. This is especially important in returnless systems.
* Low Pressure: In some setups, a second pump might be used for pre-boost, providing a lower pressure to the main pump. This arrangement requires careful pressure balancing.
4. Pump Control:
* Simultaneous Operation: Both pumps might run simultaneously. This requires careful consideration of power draw and pressure regulation.
* Sequential Operation: One pump may run initially, with the second kicking in under higher demand (e.g., during boost). This requires a more complex control system, potentially using sensors and a controller.
5. Wiring Diagram:
You absolutely MUST create a wiring diagram before you start. This diagram should show the power source, ground, relay (if used), pump wiring, and any other components (pressure regulator, controller). Properly fuse the circuit to prevent damage in case of a short.
6. Safety Precautions:
* Disconnect the battery's negative terminal before starting any work.
* Work in a well-ventilated area. Fuel fumes are highly flammable.
* Use proper fuel-resistant hose and connectors.
* Properly ground the pump.
* Use appropriately sized fuses and wiring. Undersized wiring can overheat and cause a fire.
* Test the system thoroughly before starting the engine.
In short: This is an advanced modification that requires a good understanding of automotive electrical systems and fuel delivery. If you lack this expertise, strongly consider having a qualified professional install the second fuel pump. Improper installation can lead to catastrophic failure. Don't risk your safety or your vehicle's.
