Parts for your 1997 Mitsubishi Pajero-Fuel pump

1997 Mitsubishi Pajero fuel pump — what it does and how to look after it

Yes, the 1997 Mitsubishi Pajero uses a fuel pump. On petrol V6 models (e.g., 6G72 3.0L and 6G74 3.5L), it’s an electric in-tank pump feeding the EFI rail. On the 2.8L 4M40 turbo-diesel, fuel delivery is handled by a Bosch/Zexel VE-type rotary injection pump with an integral low-pressure (transfer) stage and a hand primer on the filter head, rather than an electric in-tank lift pump. This setup is documented in Mitsubishi Pajero/Montero 1997 Workshop Manual (Group 13A Fuel—Petrol and Group 13B Diesel Fuel System), the Mitsubishi 4M40 Engine Workshop Manual, and the Haynes Montero/Pajero 1992–99 manual.

For petrol Pajeros, the in-tank electric pump’s job is simple but critical: pull fuel through the strainer, pressurise it to roughly EFI spec, and keep the rail supplied under all driving conditions. For the diesel 4M40, the VE injection pump precisely meters and pressurises fuel for each injector while its internal transfer stage draws fuel from the tank—no need for a separate electric pump.

As part of regular servicing, it’s smart to care for the pump by looking after what feeds it. Fresh, clean fuel and an on-time filter change help the pump live a long life. If the vehicle sits for ages, stale fuel can varnish the pump or gum the strainer, so try to keep the tank topped with quality fuel and run it regularly.

• Petrol models: listen for the brief prime “whirr” at key-on, if it’s noisy, intermittent, or the engine cranks long, consider a pressure test. A blocked strainer or tired pump shows up as hesitation under load. Replace the fuel filter on schedule and avoid running the tank near empty.
• Diesel 4M40: regularly drain water from the fuel filter, replace the element when due, and use the hand primer to bleed after filter changes. If hard starting or surging persists, have the injection pump and lines checked by a diesel specialist.

Pump replacement on petrol Pajeros involves safely relieving system pressure, disconnecting the battery, removing the rear access cover, lifting the sender module, and swapping the pump and strainer with new seals and O-rings. Refit carefully, cycle the key to prime, and check for leaks. There’s no fixed replacement interval—go by symptoms and test results. For diesel injection pump service, calibration and seal work are best left to a properly equipped workshop.

• Does the 2.8 4M40 diesel have an electric in-tank pump?
  No. The 4M40 uses a VE-type rotary injection pump that draws fuel itself, plus a hand primer on the filter head. There’s typically no electric lift pump in the tank on these models.
• What are common signs a petrol Pajero fuel pump is failing?
  Long cranking, loud whining from the tank, hesitation on hills, or stalling under load. A fuel pressure test at the rail will confirm whether the pump and regulator are in spec.
• What fuel pressure should the petrol system run?
  Around 300 kPa (about mid-40s psi) at the rail for many 6G7x EFI setups. Exact figures vary by engine and market—always confirm with the Mitsubishi workshop manual for your VIN.