Delphi FP10509 Fuel Injection Pressure Regulator

Fuel Pressure Control for OE Applications

The Delphi FP10509 fuel injection pressure regulator is built for vehicles that require stable fuel system pressure and precise injector delivery. It uses a metal body, push-in inlet and outlet connections, and a bolt-mount design for OE-style service on select Buick, Oldsmobile, and Pontiac applications.

Delphi draws on OE heritage and supplier experience from the original equipment side, bringing that knowledge into the aftermarket part design. The FP10509 is specified for a 51 system pressure and is a direct-fit style regulator for fuel injection systems that use a 13.0 mm inlet and outlet port diameter.

Key Features

• Fuel injection pressure regulator for air and fuel delivery systems
• Metal construction for OE-style durability
• Push-in inlet and outlet connections
• Bolt mounting type for secure installation
• 51 system pressure specification
• No gauge port and non-adjustable design
• Compatible with select Buick LeSabre, Oldsmobile Delta 88, and Pontiac Bonneville applications

Detailed Description

Delphi FP10509 is a fuel injection pressure regulator engineered for vehicles that rely on consistent fuel pressure to maintain proper injector operation. The regulator features one inlet and one outlet, both with 13.0 mm push-in ports, and a metal housing that matches the needs of OE-style fuel system service. This part number, FP10509, is used across multiple GM applications including Buick LeSabre, Oldsmobile Delta 88, Pontiac Bonneville, Buick Riviera, and Pontiac Firebird.

This part cross-references Carter PR4 and Dorman - OE Solutions 800-114 for the same application. It is also listed among interchange references including 5G1041, 25523720, 25523780, and PR101.

What It Helps Address

• Fuel pressure that is outside the specified 51 system pressure range
• Hard starting caused by unstable fuel delivery
• Rough idle related to inconsistent injector pressure
• Fuel system performance issues on OE-style injection setups
• Service replacement needs on select Buick, Oldsmobile, and Pontiac models

Installation Notes and Tips

• Verify inlet and outlet port diameter before installation; this regulator uses 13.0 mm push-in connections.
• Confirm the vehicle’s fuel system is specified for 51 system pressure.
• Check mounting location and bolt pattern against the original regulator.
• Inspect fuel lines and seals during replacement to help maintain proper pressure control.
• Use the vehicle application list to confirm year and model coverage before ordering.

Quality Assurance

Delphi builds this regulator with OE experience and supplier knowledge developed through work with major automakers. The FP10509 reflects that OE-focused background in an aftermarket replacement part for fuel injection pressure control.