Parts for your 1987 Mitsubishi Pajero-Fuel injectors

1987 Mitsubishi Pajero Fuel Injectors: What’s Fitted, What’s Not, and How to Look After Them

Referencing technical sources including the Mitsubishi Pajero/Montero Factory Service Manual (1982–1991, Engine and Fuel sections), the Mitsubishi ASA electronic parts catalogue (JPN/EUR/AUS listings), and the Haynes Repair Manual for Pajero/Montero 1983–1997, fuel injectors are relevant to many 1987 Mitsubishi Pajero models. The 2.3L and 2.5L turbo-diesel engines (4D55/4D56) use mechanical injectors fed by a rotary injection pump. Many 2.6L petrol models sold in Australia and New Zealand were carburetted and therefore do not use fuel injectors, though some markets offered petrol ECI-Multi (electronic injection) variants which do. So, injectors are used on 1987 diesel Pajeros and on any petrol Pajero with ECI-Multi, they’re not used on carburetted petrol versions.

Where fitted, the fuel injector’s job is simple but critical: meter the right amount of fuel and atomise it neatly so the engine burns cleanly, pulls strongly, and doesn’t drink more than it should. On 1987 diesel Pajeros, the mechanical injectors pop open at a set pressure and create a fine spray into the pre-combustion chamber. On petrol ECI-Multi models, each injector is pulse-controlled for precise fuelling across revs and load.

Keeping injectors happy pays off in smoother idle, easier cold starts and better economy. For diesels, it’s smart to have the injectors pop-tested and spray-pattern checked by a diesel specialist every 100,000–150,000 km, or sooner if there’s hard starting, excess smoke, diesel knock, or rough running. Worn nozzles, dribbly tips, and tired sealing washers are common on high-kilometre 4D55/4D56 engines and can be refreshed without replacing the entire body. Always renew copper washers and leak-off hoses during refit, and torque to spec to avoid compression blow-by.

Petrol ECI-Multi injectors benefit from new O-rings and filters when doing intake work. Professional ultrasonic cleaning can revive flow and spray pattern. If an injector is electrically open/short or way down on flow, replace it as a matched set for best balance.

• Typical symptoms of injector issues: hard starts, misfire under load, black/white smoke (diesel), poor fuel economy, fuel smell, or wet plugs (petrol).
• Use quality fuel, change filters on schedule, and don’t ignore minor misfires—they can cook pistons or melt cats on petrol models.
• After any injector work, check for leaks with the engine running and re-bleed diesel lines as required.

If your 1987 Pajero is the carburetted petrol type, it doesn’t use fuel injectors, fuelling is handled by the carburettor and related vacuum and choke systems. In that case, servicing focuses on carb overhaul, float level, jets, and vacuum hose integrity rather than injector maintenance.

Popular questions

How can someone tell if their 1987 Pajero actually has fuel injectors?
Check the engine type. The 2.3/2.5 turbo-diesel (4D55/4D56) definitely uses injectors. Many 2.6L petrols in AU/NZ are carburetted (no injectors), but if it’s labelled ECI-Multi or has an injector rail on the intake, it’s injected. The build plate and the air intake layout are quick giveaways.

How often should diesel injectors be serviced on a 1987 Pajero?
Every 100,000–150,000 km is a fair interval for pop-testing and spray checks, or sooner if there’s smoke, rough idle, or hard starts. Fresh washers and leak-off hoses at refit keep things tidy and leak-free.

Will injector cleaner fix rough running on a mechanical-injection diesel?
It can help mild deposits, but it won’t cure worn nozzles or poor pop pressure. If symptoms persist after a filter change and good fuel, a bench test and proper service are the go.