Parts for your 2004 Toyota Mark x-Fuel pump

2004 Toyota Mark X fuel pump — what it does and how to look after it

A fuel pump is absolutely relevant and fitted to the 2004 Toyota Mark X (GRX120/121). In fact, these models with the 4GR-FSE 2.5L and 3GR-FSE 3.0L direct‑injection V6s run two pumps: an in‑tank electric low‑pressure pump and an engine‑mounted mechanical high‑pressure pump. Toyota’s New Car Features (NCF) for the GR‑series D‑4 system, the Toyota Mark X Repair Manual, and the Toyota Electronic Parts Catalogue all describe the in‑tank “fuel suction with pump and gauge” assembly and the cam‑driven high‑pressure pump supplying the common rail. So yes—this car definitely uses a fuel pump, actually a pair working together.

On the Mark X, the in‑tank pump lifts petrol from the tank, keeps it cool, and feeds the high‑pressure pump at a steady low pressure. The engine‑mounted pump then ramps pressure way up for the D‑4 injectors, delivering sharp, clean atomisation for power and economy. Because the two pumps depend on each other, low in‑tank pressure often shows up as weak high‑side rail pressure, long cranking, surging under load, or DTCs like P0087.

As part of routine servicing, the fuel pump isn’t a scheduled replacement item, but a bit of care goes a long way. Keep at least a quarter tank to help cool the in‑tank unit, use quality 95 RON petrol where available, and avoid contaminating the tank during refuelling. The in‑tank strainer and internal filter are part of the module