Walbro Fuel Pump GSL In-Line — 255 LPH, 10 mm x 1.00 Female Fittings, Gasoline

Walbro's GSL in-line electric fuel pump delivers up to 255 liters per hour of gasoline flow through 10 mm x 1.00 female inlet and outlet fittings for reliable EFI performance.

This compact, in-line Walbro fuel pump is designed for electronic fuel injection systems and high-demand applications such as turbocharged or supercharged engines. Manufactured under TI Automotive, these pumps meet OE-style form and function while offering a direct-replacement fit for older vehicles like the 1985–1987 Honda Prelude and many modern EFI conversions. The pump is sold individually and intended solely for gasoline use.

How much fuel can this pump move and where does it install?

This Walbro GSL unit pumps up to 255 liters per hour (LPH), making it suitable for many street and performance EFI setups. It is an in-line, external pump that mounts along the fuel line between the tank and the engine, not inside the tank.

• Flow rate: 255 LPH continuous capacity
• Connection type: 10 mm x 1.00 female inlet and outlet
• Mounting: external/in-line installation on fuel line
• Fuel compatibility: gasoline (petrol) only

Will this fit my vehicle or performance build?

The pump fits many EFI systems and is a documented replacement for the 1985–1987 Honda Prelude. It also suits turbocharged and supercharged engines where increased fuel flow is required. Verify inlet/outlet thread size and electrical compatibility before ordering.

• Stock replacement fit for Honda Prelude (1985–1987)
• Compatible with most EFI conversions and aftermarket fuel systems
• Check that your fuel hose/adapters match 10 mm x 1.00 female fittings
• Confirm your vehicle’s electrical supply and relay capacity

What are the product origin and brand details?

Although branded Walbro, this pump is manufactured by TI Automotive, the company that owns the Walbro name. New Walbro pumps are stamped with the TI Automotive mark but retain Walbro engineering and specifications. The pump ships as a single unit and includes no additional accessories.

• Manufacturer: TI Automotive (Walbro brand owner)
• Labeling: new pumps carry the TI Automotive stamp
• Sold: individually — fuel pump only, no fittings or wiring harness included

How should I plan installation and supporting parts?

Install the pump inline using suitable fuel-rated hose, clamps, and an appropriate fuel pump relay and fuse. Use anti-vibration mounts where possible and position the pump to avoid excessive heat; follow good practice for wiring and fuel line routing to ensure long service life.

• Use fuel-rated hose or adapter fittings for 10 mm x 1.00 threads
• Install a dedicated relay and fuse sized for pump current draw
• Mount away from exhaust heat and use vibration isolators
• Prime and test the system for leaks before full operation

Who is this for? This Walbro GSL 255 LPH in-line pump is aimed at enthusiasts and mechanics upgrading or replacing fuel delivery on EFI engines that require a moderate-to-high flow external pump. It's ideal for classic cars seeking OE-style replacement pumps, as well as street and mildly tuned forced-induction applications. Ensure fitment, electrical capacity, and fuel compatibility before purchase; if you need higher flow or an in-tank solution, consider other Walbro models designed for those roles.