Mitsubishi L2A, L2C, L2E, L3A, L3C and L3E: fuel, injection and starting
Does your Mitsubishi L3E or L2E start poorly, or does it run unevenly? Almost always the cause lies in the fuel system, the injectors or the preheating. In this blog we walk through the fuel and starting system of the L-series, with the key values and how to correctly bleed the system after a filter change.
Suitable for the entire series: Mitsubishi L2A, L2C, L2E, L3A, L3C and L3E. The fuel and starting system is identical in design; the three-cylinder has one extra injector.
The fuel system in brief
Fuel flows from the tank via a feed pump and a fuel filter to the Bosch-type NC injection pump, which sends the fuel under high pressure to the injectors. The L-series works with a swirl chamber (indirect injection) and throttle-type injectors. The opening pressure of the injectors is 140 kgf/cm² (approximately 1,991 psi).
| Component | Type / value |
|---|---|
| Injection pump | Bosch-type NC |
| Injector | Throttle-type, swirl chamber |
| Injector opening pressure | 140 kgf/cm² (1,991 psi) |
| Glow plug | Sheathed type |
A few useful torque values here: fuel line nut 24.5–29.4 N·m, delivery valve holder 34.3–39.2 N·m, injector holder 49.0–58.8 N·m, injector lock nut 34.3–39.2 N·m, and the bleed bolt on the injection pump 4.9–6.9 N·m.
Preheating and starting
The L-series has sheathed-type glow plugs and requires preheating for almost every start, even in milder temperatures. Wait for the preheating indicator (with a cold engine this can easily take ten to twenty seconds) before starting. If it starts poorly when cold, this is usually due to a worn glow plug, a weak battery or air in the fuel system. A starter motor that turns too slowly also makes diagnosis more difficult; so first make sure the battery and starter motor are in good condition.
Bleeding the fuel system
After a filter change or after the tank has run empty, air gets into the system and the engine won't start or starts with difficulty. In that case, bleed it as follows:
- Open the fuel cock and make sure there is enough diesel in the tank.
- Loosen the bleed bolt on the injection pump (or the filter) and pump the hand pump on the feed pump until fuel comes out without air bubbles.
- Tighten the bleed bolt again (4.9–6.9 N·m).
- If necessary, also loosen the union nuts at the injectors by one turn, turn the engine over until fuel appears there, and tighten them again.
- Start the engine; it should now start smoothly.
Running unevenly or starting poorly
If it runs unevenly on one cylinder, check whether the delivery valve holder on the injection pump for that cylinder is properly tightened and whether the injector is spraying correctly. If someone has recently worked on the injection pump and it starts poorly afterwards, check the shims under the pump: these determine the setting. The pump itself is generally very reliable.
Fuel and starting parts in stock: fuel feed pump, complete injector or a separate injector nozzle, glow plugs, a starter motor and the stop solenoid. Order using your engine number.
Frequently asked questions
Why does my Mitsubishi L3E start poorly when cold?
Usually due to worn glow plugs, a weak battery or air in the fuel system. Always wait for the full preheating indication before starting.
How do I bleed the fuel system?
Open the fuel cock, loosen the bleed bolt on the injection pump and pump the hand pump until fuel comes out without bubbles. Tighten it again and start; if no fuel appears at the injectors yet, briefly loosen the union nuts there and turn the engine over.
What is the opening pressure of the injectors?
140 kgf/cm² (approximately 1,991 psi). Have the injectors tested and adjusted if the engine runs unevenly or smokes.
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