Parts for your 2005 Toyota Mark x-Fuel pump

2005 Toyota Mark X fuel pump — what it does and how to look after it

Yes, the 2005 Toyota Mark X uses a fuel pump. Technical references including Toyota’s New Car Features for the 3GR-FSE/4GR-FSE D-4 engines, the GRX120/125 Repair Manual (Fuel section: Fuel Pump Removal/Installation), and the Toyota Electronic Parts Catalogue (PNC 77020, Fuel Pump Assembly) confirm the car is fitted with an in-tank electric supply pump feeding an engine-mounted high-pressure pump used by the D-4 direct-injection system.

On this Mark X, the in-tank electric pump’s job is to lift petrol from the tank and deliver a steady low pressure to the high‑pressure mechanical pump on the cylinder head. That second pump then ramps pressure up for direct injection. When the in-tank pump goes weak, the high-pressure side can’t keep up, leading to hard starting, hesitation under load, or lean/rich faults. Common tell-tales are a loud whine from the tank, sluggish hill climbs, or DTCs related to fuel pressure.

There’s no fixed replacement interval in Toyota servicing for the in-tank pump