Walbro/TI 255 LPH In-Tank EFI Fuel Pump Kit — GCA758

A proven upgrade for EFI swaps and refreshes. This in-tank electric pump flows up to 255 LPH and supports typical EFI base pressures with rock-solid delivery. Kit includes the pump and install components for common GM-style sending units—ideal for LS swaps, retrofit tanks, and street/strip builds. Verify your module dimensions and connector before ordering.

Why builders choose this pump

Trusted output: 255 LPH free-flow rating for healthy headroom on typical EFI systems.
Compact & in-tank: Quiet operation and OEM-style packaging; no external pump noise or extra plumbing.
Complete kit: Includes pump and install pieces (strainer/sock, short hose, clamps, pigtail—see photos).
Swap friendly: Popular across GM retrofit/swap applications when matched to the correct sending unit.

Performance & specs

Spec	Detail
Flow	Up to 255 LPH (≈67 GPH) free-flow
Type	In-tank, 12 V electric
Typical EFI use	Stable supply at common base pressures (≈40–60 PSI with regulator)
Included	Pump, strainer/sock, short submersible hose, clamps, wiring pigtail (see images for exact contents)
Fuel compatibility	Gasoline and ethanol blends. For sustained E85 use, upgrade the entire system (filters, hose, seals) and note that long-term service life may be reduced versus gasoline.

Fitment & install notes

Sending unit: Confirm physical fit (pump length/diameter), electrical connector, and outlet size for your module before install.
Filtration: Use the included in-tank strainer and add a ≤10 μm EFI filter on the pressure side to protect injectors.
Plumbing: Pair with PTFE AN hose and a return-style EFI regulator for best pressure control.
Setup: After assembly, key-on prime, check for leaks, and verify base pressure at the rail. Re-check after the first drive.

Compatibility quick-check (GM-style modules)

Pump packaging: Verify your sending unit can accept a standard 255 LPH in-tank pump body and strainer footprint (check bracket/strap length and clamp size).
Electrical connector: Many retrofit/swap modules use a 2-pin pump lead. This kit includes a pigtail—match polarity (positive to pump “+”), solder/heat-shrink, and route away from the float arm.
Outlet & hose: Confirm outlet barb size/orientation and use submersible EFI hose inside the tank. Use EFI clamps—avoid generic worm clamps.
Strainer orientation: Choose the strainer angle that clears the bucket floor and avoids the float sweep. Keep the sock level.
Top-hat pass-through: Ensure the bulkhead wiring and feed tube are rated for EFI pressure and current draw.

Tip: If your module used a small, low-output OE pump, plan to upgrade the pre/post filters and run a proper return-style regulator for stable rail pressure.

How much horsepower will a single 255 LPH pump support?

Gasoline: up to ≈500 wheel hp (≈590 crank hp) at typical EFI base pressure (43.5–58 psi).
E85: up to ≈380 wheel hp (≈450 crank hp) at typical EFI base pressure (43.5–58 psi).

Assumptions: healthy pump voltage (~13.5 V), clean ≤10 μm post-pump filter, return-style regulator, and properly sized plumbing (-6 / -8 AN). Boosted setups, higher base pressure, hot fuel, or altitude will reduce headroom—leave 15–25% margin. For sustained E85 or more power, step up to a higher-flow or dual-pump solution.

Shop EFI Filter (AN male) Shop EFI Filter (ORB) Shop ORB⇄AN Adapters

FAQ

Is this pump PWM compatible?

Short answer: no. This 255 LPH in-tank pump is a brushed DC design intended for constant 12–14 V supply. Pulse-width modulation (PWM) control can cause excess heat and brush wear, noisy operation, and pressure instability—especially at lower duty cycles.

What to do instead: run the pump at full system voltage through a dedicated relay and regulate pressure with a return-style EFI regulator.
Factory PWM systems: if your OEM module uses PWM, bypass or reconfigure it to provide constant voltage to the pump, or use a controller designed to supply smooth, non-PWM power.
Why it matters: PWM “chopping” reduces effective voltage and can starve the rail under transient load, while also heating the motor and shortening service life.

For builds that require electronic flow control, consider a pump/platform engineered for controller operation (often brushless) and pair it with the manufacturer’s recommended controller.

Is this pump E85 compatible?

Conditionally. The pump and kit components are commonly used with ethanol blends; many sellers list flex-fuel/E85 validation. In practice, sustained full-time E85 can shorten service life versus gasoline, especially if voltage is low or filters are neglected.

Best practice: if you plan to run E85 long-term, choose an E85-specific pump and ensure your entire system—filters, hose (SAE J30R10 or PTFE), O-rings, bulkhead pass-throughs—is ethanol rated.
Maintenance: E85 can loosen tank deposits; change the post-pump filter early and monitor the in-tank strainer.

For occasional E85 use, keep voltage healthy (~13.5 V), avoid clogged filters, and leave extra headroom in your fuel system.

What’s the warranty?

90-day manufacturer warranty. Coverage is handled by the pump manufacturer. Keep your proof of purchase and follow their claim process for defects.

Every pump is tested before it leaves the factory to verify operation and flow.
Use proper filtration (≤10 μm post-pump), wiring/relays, and installation practices—improper setup can void coverage.

Need help diagnosing an issue? Contact us first—we can often resolve setup problems before a warranty claim is necessary.

What’s included

(1) 255 LPH in-tank EFI pump.
Install components: strainer, submersible hose, clamps, wiring pigtail (see images for exact contents).

Safety: Work in a ventilated area away from ignition sources. Depressurize the system, capture spills, and replace any brittle hoses during service.