Delphi MF0033 Mechanical Fuel Pump

Delphi MF0033 Mechanical Fuel Pump

The Delphi MF0033 is a standard replacement mechanical fuel pump for gasoline applications that require a 7 psi system pressure and a 25 average flow rating. Built from Delphi’s OE heritage, it brings application-specific engineering to classic truck and van fuel systems, including Chevrolet P30 and GMC P3500 models with a 3 line pump setup.

Key Features

• Mechanical fuel pump for gas fuel systems
• 7 psi system pressure for OE-style fuel delivery
• 25 average flow rating
• Hose bead inlet with 0.500 in. outside diameter
• Threaded outlet with 5/8-18 UNF outlet fitting thread size
• Two outlet ports
• Gasket or seal included
• Standard replacement grade for service repairs
• Package contents: mechanical fuel pump, gasket, instruction sheet

Detailed Description

Delphi MF0033 is a mechanical fuel pump engineered for gasoline-powered vehicles that need dependable fuel delivery from a belt- or cam-driven pump design. The threaded outlet, hose bead inlet, and dual outlet configuration support the factory-style plumbing used on many Chevrolet and GMC medium-duty and heavy-duty applications. This part number is built with Delphi’s OE experience and aftermarket coverage for older vehicle platforms, including Chevrolet P30, Chevrolet R30, Chevrolet C20, Chevrolet C30, GMC P3500, GMC R3500, GMC C2500, GMC C3500, and related Suburban applications listed below. This part cross-references Airtex Fuel Pumps 42440 for the same application.

Vehicle Fitment

• Fits 1986-1989 Chevrolet P30, N/A; fits vehicles with a 3 line pump.
• Fits 1989 Chevrolet R3500, N/A; fits vehicles with a 3 line pump.
• Fits 1986-1989 GMC P3500, N/A; fits vehicles with a 3 line pump.
• Fits 1987-1989 GMC R3500, N/A; fits vehicles with a 3 line pump.
• Fits 1987-1988 Chevrolet R30, N/A; fits vehicles with a 3 line pump.
• Fits 1986 Chevrolet C20, N/A; with 3 line pump; with Federal Emission System.
• Fits 1986 Chevrolet C20 Suburban, N/A; fits vehicles with a 3 line pump.
• Fits 1986 Chevrolet C30, N/A; fits vehicles with a 3 line pump.
• Fits 1986 GMC C2500, N/A; fits vehicles with a 3 line pump.
• Fits 1986 GMC C2500 Suburban, N/A; fits vehicles with a 3 line pump.
• Fits 1986 GMC C3500, N/A; fits vehicles with a 3 line pump.
• Fits 1985 Chevrolet C20, N/A; with 3 line pump; from 01/1985.
• Fits 1985 Chevrolet C20 Suburban, N/A; with 3 line pump; from 01/1985.
• Fits 1985 Chevrolet C30, N/A; with 3 line pump; from 01/1985.
• Fits 1985 Chevrolet P30, N/A; with 3 line pump; from 01/1985.
• Fits 1985 GMC C2500, N/A; with 3 line pump; from 01/1985.
• Fits 1985 GMC C2500 Suburban, N/A; with 3 line pump; from 01/1985.
• Fits 1985 GMC C3500, N/A; with 3 line pump; from 01/1985.
• Fits 1985 GMC P3500, N/A; with 3 line pump; from 01/1985.

Common Repair Uses

• Restores fuel delivery on a worn mechanical pump
• Addresses hard-start or no-start conditions caused by low fuel pressure
• Helps correct fuel starvation under load
• Replaces a leaking pump or damaged gasket sealing surface
• Supports service on 3 line pump Chevrolet and GMC applications

Installation Notes and Tips

Verify the vehicle uses a 3 line pump before ordering. Confirm the outlet thread size, inlet style, and fuel line routing against the original pump, especially on 1985-1986 Chevrolet and GMC trucks with application notes such as Federal Emission System or from 01/1985 build dates. Replace the gasket during installation and inspect fuel lines, mounting surfaces, and the pump drive interface for wear or contamination.

Quality Assurance

Delphi draws on more than a century of OE experience and supplier knowledge used by major automakers. The MF0033 reflects that OE-based engineering approach in a standard replacement mechanical fuel pump for classic Chevrolet and GMC fuel system service.