Delphi FP10400 Fuel Injection Pressure Regulator

Fuel Pressure Control for OE-Style Performance

The Delphi FP10400 fuel injection pressure regulator is built for precise fuel system control in select Nissan, INFINITI, and Mercury applications. With OE heritage behind the design, it supports consistent fuel pressure delivery for drivability and engine response.

Compatible with 1993-2004 Nissan Frontier, Xterra, Quest, Pathfinder, and INFINITI QX4 applications, the Delphi FP10400 is a direct-fit fuel injection pressure regulator for vehicles that require a 44 psi system pressure specification.

Key Features

• Metal construction for fuel system durability
• Fixed-pressure design; not adjustable
• 44 psi system pressure specification
• 1 inlet with push-in connection
• 1 outlet with hose connection
• Bolt-on mounting type
• No gauge port
• OE-informed aftermarket design from Delphi

Detailed Product Overview

Delphi FP10400 is a fuel injection pressure regulator engineered around OE experience and supplier knowledge developed over decades of original-equipment service. It uses a metal body, an 11.0 mm inlet port diameter, and an 8.0 mm outlet port diameter to match the specified fuel system layout. This part cross-references Standard Ignition PR95 and Walker Products 255-1075 for the same application.

For drivers searching for a fuel injection pressure regulator for 1996-2000 Nissan Pathfinder, 1997-2000 INFINITI QX4, or 1999-2004 Nissan Frontier and Xterra, the Delphi FP10400 provides the correct pressure-control architecture for the listed vehicles. It also fits 1999-2002 Nissan Quest and 1993-1998 Mercury Villager applications.

Common Problems This Part Addresses

• Fuel pressure that is outside the specified range
• Hard starting caused by unstable fuel delivery
• Rough idle related to pressure regulation issues
• Fuel mixture concerns tied to inconsistent rail pressure
• Driveability problems on Nissan Frontier, Xterra, Pathfinder, Quest, QX4, and Mercury Villager applications

Installation Notes and Tips

Verify the inlet and outlet connection style before installation: this regulator uses a push-in inlet and hose outlet with bolt mounting. Confirm the vehicle’s fuel system calls for a 44 psi regulator and match the application by year, make, and model before replacement. Clean surrounding fuel system components during service and inspect hoses and seals for wear before reassembly.

Quality Assurance

Delphi builds this regulator using OE experience and knowledge gained from supplying major automakers, with aftermarket construction informed by original-equipment standards. The FP10400 is intended to meet the fitment and pressure requirements listed for the covered Nissan, INFINITI, and Mercury applications.