Fuel Injector 400903-00104 0445120376 for Doosan

Fuel Injector 400903-00104 0445120376 for Doosan

This fuel injector is engineered as a direct replacement for the Doosan. Manufactured to meet or exceed OEM specifications, it delivers reliable performance in demanding conditions. Each unit is tested for fuel flow, pressure rating, and durability before leaving the factory to ensure consistent quality across every order.

Vehicle Compatibility

Replaces OEM Part Numbers

400903-00104

Signs You Need a Replacement

If your equipment is showing any of these symptoms, the injectors & nozzle may be the cause:

• Rough idle or misfire — Uneven fuel delivery from a worn injector causes the engine to shake at idle. On Doosan engines, this is often accompanied by a knocking sound under load.
• Black or white exhaust smoke — Black smoke means excess fuel; white smoke indicates incomplete combustion. Both point to injector spray pattern degradation.
• Loss of engine power — A single failing injector reduces cylinder output. Multi-cylinder engines lose noticeable power when one injector flows less than the rest.
• Increased fuel consumption — Poor atomization means the engine burns more fuel to produce the same power. Monitor your fuel burn rate as an early warning sign.
• Hard starting or no start — If the injector doesn’t deliver fuel on cranking, the cylinder won’t fire. This is especially common in cold weather with worn nozzles.
• Fuel in engine oil (dilution) — Fuel leaking past the injector seat seal contaminates the crankcase oil. If the oil level rises or smells of diesel, inspect the injectors immediately.

Replace as a Set

Replace all injectors as a set whenever possible. On Doosan engines, mixing old and new injectors creates uneven fuel delivery — the new injectors compensate for the worn ones, shortening their life. When installing, use new copper sealing washers and torque to the specification in the service manual. After installation, run the engine at idle for 5 minutes to bleed air from the fuel system, then check for leaks at each injector connection before putting the machine under load.

Frequently Asked Questions

Which Doosan models does this part fit?
Refer to the Vehicle Compatibility table above for the full list of Doosan models. Each listing includes the body type, engine, and production years. Match your vehicle’s engine code (stamped on the engine block) against the listed codes to confirm.

Does this replace OEM number 400903-00104?
Yes. This is a direct aftermarket replacement for 400903-00104. It matches the original dimensions, connector type, and operating specifications. No modifications to your vehicle or equipment are required.

My vehicle is a 0903 model – is it covered?
The compatibility range for this part includes 0903-0010. The 0903 model year falls within this range, but verify the engine code and body type match. Mid-year production changes sometimes mean two vehicles from the same model year use different parts.

What are the common failure signs on a Doosan engine?
On Doosan engines, watch for black exhaust smoke under load, rough idle, misfire codes (P0300 series), and loss of power. A single failing injector can reduce engine output by up to 25%. If you notice fuel in the engine oil, the injector seat seal is likely compromised.

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