Delphi FP10439 Fuel Injection Pressure Regulator

Fuel Pressure Control for OE Applications

The Delphi FP10439 fuel injection pressure regulator is built for precise fuel system control in select Ford, Mazda, and Mercury applications. With a metal body, push-in inlet, hose outlet, and a 44 psi system pressure rating, it supports stable fuel delivery for drivability and fuel metering accuracy.

Compatible With 1986-1989 Mazda 323, 1989 Ford Festiva, and 1988-1989 Mercury Tracer applications, this Delphi FP10439 regulator is a direct-fit service part for vehicles that rely on consistent fuel pressure at the rail or delivery circuit.

Key Features

• Fuel injection pressure regulator for air and fuel delivery systems
• Metal construction for durable service in engine bay conditions
• Push-in inlet and hose outlet configuration
• Fixed design with no adjustment provision
• Single inlet and single outlet layout
• 44 psi system pressure specification
• Bolt-mounted installation style
• No gauge port

Detailed Description

Delphi FP10439 is engineered as an OE-style fuel injection pressure regulator for select compact Ford, Mazda, and Mercury vehicles. Delphi draws on more than a century of OE experience, and that heritage is reflected in the part’s material selection, port design, and pressure specification. The regulator uses a 0.43 in. (11.0 mm) inlet port and a 0.24 in. (6.0 mm) outlet port, with a push-in inlet and hose-style outlet for the listed applications. This part cross-references Standard Ignition PR32 and PR210 for the same application.

Fits 1986-1989 Mazda 323, N/A. Fits 1989 Ford Festiva, N/A. Fits 1988-1989 Mercury Tracer, N/A. Fits 1991-1994 Mercury Capri, N/A, stamped #B6B313280A.

Common Fuel System Issues

• Fuel pressure that is too high or too low for proper injector operation
• Hard starting caused by unstable fuel delivery
• Rough idle or hesitation under acceleration
• Fuel smell or rich-running symptoms tied to pressure regulation problems
• Driveability issues from inconsistent fuel metering

Installation Notes and Tips

Verify the inlet and outlet port sizes, mounting style, and system pressure before installation. Confirm the vehicle’s stamped reference number where applicable, especially on 1991-1994 Mercury Capri applications noted with stamped #B6B313280A. Inspect fuel lines and connections for wear or contamination during replacement to help maintain proper sealing and pressure control.

Quality Assurance

Delphi builds aftermarket parts using OE heritage and engineering knowledge developed through long-term supplier experience with major automakers. The FP10439 is manufactured to support consistent fuel system performance in the listed applications.