Parts for your 1989 Mitsubishi Pajero-Fuel injectors

1989 Mitsubishi Pajero fuel injectors — what they do and how to look after them

Based on factory and aftermarket references — including the Mitsubishi Pajero/Montero L040 Series Service Manual (1988–1990), Mitsubishi 4D56 Diesel Engine Service Manual, Mitsubishi 6G72 ECI‑Multi Workshop Manual, and Haynes/Gregory’s guides covering 1983–1993 Pajero — fuel injectors are relevant to many 1989 Pajero variants. The 3.0‑litre 6G72 V6 with ECI‑Multi uses electronic petrol injectors, while the 2.3/2.5‑litre 4D55/4D56 diesels use mechanical injectors fed by a rotary pump. Some 2.6‑litre 4G54 petrol models were carburetted and do not have injectors. If yours is a V6 or diesel, injectors are part of normal servicing.

On a 1989 Pajero, injectors are there to meter and atomise fuel so the engine runs cleanly and pulls strongly. Petrol ECI‑Multi injectors fire into the intake ports, coordinated by the ECU. Diesel injectors pop open at a set pressure to spray into the pre‑combustion chambers. Either way, good spray patterns mean easier starts, smoother idle, better economy and fewer smoky moments under load — too right.

Servicing is about keeping fuel clean and the spray pattern crisp. Petrol owners can plan on professional ultrasonic cleaning and flow‑testing every 80–120,000 km, or sooner if there’s rough idle, misfire or rising fuel use. Diesel owners should have pop pressures and nozzles checked around 150–200,000 km, worn nozzles or dribbly patterns can make for hard starts, knock and soot. Replace perished injector seals and insulators on petrol rails, and always fit fresh copper washers on diesel injectors.

• Use quality fuel and change filters on schedule to protect the injectors.
• For petrol ECI‑Multi: depressurise the rail before removal, handle O‑rings carefully, and avoid mixing up connectors.
• For diesel 4D55/4D56: crack lines cleanly, keep everything spotless, fit new sealing washers, and bleed the system after refit.
• If lines or fittings are disturbed, don’t overtighten — leaks and cracked lines are a real headache.
• No coding is required on these pre‑OBD systems, but a post‑service check for leaks and balance is a must.

If a 1989 Pajero happens to be the carburetted 2.6‑litre, injector servicing doesn’t apply — that engine meters fuel via a carburettor instead. Not sure what’s under the bonnet? Check the engine code and fuel system notes in the service book or the under‑bonnet build plate.

Popular questions about 1989 Mitsubishi Pajero fuel injectors

Does every 1989 Pajero have fuel injectors?
Not every one. The 3.0‑litre V6 (ECI‑Multi) and all diesels (4D55/4D56) do. Many 2.6‑litre 4G54 petrol models were carburetted, particularly in Australasian markets, so they won’t have injectors to service.

How often should the injectors be serviced?
Petrol ECI‑Multi: inspect around 80–120,000 km or if there are symptoms like misfire, rough idle or high consumption. Diesel 4D55/4D56: test pop pressure and spray pattern every 150–200,000 km, or earlier if starting gets harder or there’s excess smoke or clatter.

What are the signs the injectors need attention?
Hard starts, lumpy idle, hesitation, poor economy, diesel knock, smoke, or fuel smells. On petrol, wet or cracked O‑rings are common, on diesel, black soot around an injector can point to a leaking copper washer.