Troubleshooting Methods for Fuel Injectors

Basic knowledge of fuel injectors

A fuel injector is a device that atomizes and injects fuel into an internal combustion engine. The injectors atomize the fuel and deliver it directly into the combustion chamber at precise points in the combustion cycle. Undoubtedly, there are many fuel injectors on the market for different engine brands like fuel injector 400903-00074d for Doosan d24, whose application includes different model of Bobcat excavator, skid steers, and compact track loaders. Therefore, it is best to check with the supplier before purchasing the fuel injector you need. Sometimes you don't necessarily need to buy a new one when your fuel injector isn’t working properly, and knowing how to troubleshoot fuel injectors can be a money saver. The following are the troubleshooting methods for different faults of the fuel injector.

Troubleshooting methods for fuel injectors

Little or no fuel injection

a. There is air in the oil circuit of the fuel system-remove the air in the high-pressure or low—pressure oil pipe.

b. The fuel injector parts are seized—grind or replace.

c. The oil supply of the fuel injection pump is abnormal—find out the cause and deal with it according to the troubleshooting method of the fuel injection pump.

d. Oil leakage from the high-pressure oil pipe—tighten the nut, and if the oil pipe has cracks, it should be replaced.

e. Injection nozzle parts are worn—replace or repair.

Low injection pressure

a. The pressure regulating screw is loose—readjust to the specified pressure according to the regulations, and tighten the lock nut.

b. Deformation of pressure regulating spring—adjust or replace.

c. The needle valve is stuck—clean or grind.

d. Spring seat, ejector rod and other parts are worn—repair or replace.

High injection pressure

a. The spring tension of the pressure regulating spring is high—readjust to the specified pressure according to the regulations, and tighten the lock nut.

b. Needle valve stuck—clean or grind.

c. The spray hole is clogged—clean the spray hole or replace the injection nozzle.

Fuel injector leakage

a. The pressure regulating spring is broken—replace it with a new spring.

b. The seating surface of the needle valve body is damaged—replace it.

c. The needle valve is seized—clean and repair or replace.

d. Tight cap changed row—replace.

e. The plane of the injector body is worn—grind or replace.

Poor atomization of fuel injection

a. The fuel injection pressure is low—adjust to the specified pressure.

b. The seat surface of the fuel injector is damaged or burnt out—repair or replace it.

c. There is garbage on the mating surface of the fuel injector assembly—clean it in time.

Fuel injection into line

a.The nozzle hole is blocked—use a steel wire with a diameter of 0.2-0.3MM to clear the nozzle hole.

b. The seating surface of the needle valve body is excessively worn—replace with a new needle valve body.

c. The needle valve is seized—clean and repair or replace.

Lastly, if the surface of the needle valve is burnt or blue-black (the diesel engine is overheated), check the cooling system and pay attention to replace the pair. Please keep it in mind that do not overload the diesel engine for a long time.