2026-10-08 · 5 min read
Mitsubishi Eclipse Cross Fuel Injector Service Malaysia
The 4B40 direct injection engine uses high-pressure fuel injectors that spray directly into the combustion chamber. Over time, carbon deposits or injector wear can affect spray pattern, leading to rough idle, misfires, and increased fuel consumption. Injector cleaning can be performed via chemical additives or professional ultrasonic cleaning. A diagnostic scan identifying misfire codes for specific cylinders helps pinpoint which injector is affected. Replacement injectors should match OEM specifications for the direct injection system.
Fuel injectors spray a fine mist of petrol directly into the combustion chamber (or intake port). Over time, carbon deposits and varnish from Malaysian petrol build up on the injector tips, disrupting the spray pattern and causing rough idle, increased fuel consumption, and hesitation.
Symptoms of dirty or faulty injectors
- Rough idle — engine vibrates or shakes at traffic lights
- Increased fuel consumption without any change in driving habits
- Hesitation or stumble when pulling away from standstill
- Failed emissions test — HC (hydrocarbons) reading too high
- Check engine light with misfire codes (P0300–P0308)
Cleaning vs replacement
For most cases, professional ultrasonic injector cleaning (off-car) restores flow rate to within 3–5% of new. This is far cheaper than replacement and effective for moderate carbon build-up.
Cost at 4M Car Care: cleaning RM 150–300 (full set), replacement RM 300–800 per injector for OEM-quality units. Direct injection engines (GDI, TFSI, EcoBoost) accumulate carbon faster and typically need cleaning every 40,000–60,000 km.