Parts for your 1987 Mitsubishi Pajero-Fuel pump

1987 Mitsubishi Pajero fuel pump: what it does and how to look after it

Based on technical references including the Mitsubishi Pajero Factory Service Manual for 1983–1991 (L040/L141), Gregory’s/Haynes Pajero manuals, and Bosch/Zexel VE rotary injection pump guides, the 1987 Mitsubishi Pajero does use a fuel pump. On petrol models (the 2.6‑litre 4G54 with a carburettor), it’s a cam-driven mechanical pump mounted on the engine. On diesel models (2.5‑litre 4D56), fuel supply is handled by a mechanical lift stage integrated into the Bosch/Zexel VE‑type injection pump, assisted by the hand primer on the filter head. No in‑tank electric pump was standard on ’87 models.

The pump’s job is simple but crucial: move clean fuel from the tank to the carb or injection system at the right flow and pressure so the Pajero runs smoothly under load, on climbs, and in hot conditions. A healthy pump helps prevent lean running in the petrol engine and reduces cavitation and wear in the diesel injection pump.

For servicing, workshop literature recommends keeping the fuel system clean and airtight. Replace the fuel filter regularly (often every 10,000–20,000 km in dusty or outback use), check rubber hoses for cracks, and inspect hose clamps and the filter head primer for air leaks. On the 4G54 mechanical pump, look for seepage at the weep hole or a fuel smell in the oil (a sign the diaphragm’s gone). On diesels, make sure the hand primer firms up