A faulty injector can also be detected by loosening the union nuts in order while the engine is running at fast idle. If the number of revolutions does not change when the union nut is loosened, the corresponding injector is defective. The injector can be checked with a pressure gauge (performed in the workshop). Required injection pressure: 120–140 bar.
The first signs of a bad injector are:
- interruptions in the operation of the cylinders;
- knocking in one or more cylinders;
- engine overheating;
- drop in engine power;
- too black exhaust gas;
- high fuel consumption.
Removing
1. Carefully clean the outside of the high pressure fuel lines and fuel return lines with a cold cleaner or diesel fuel.
2. Remove the high pressure fuel lines in the kit, to do this, loosen the union nuts on the pump and injectors with a slotted ring wrench. At the same time, hold the mount with a regular key. Do not change the shape of the pipeline bend.
Attention! After removing the fuel lines, plug the holes with suitable plugs to prevent dirt and foreign bodies from entering.
3. Disconnect the fuel return hose.
4. Loosen the return line nuts.
Attention! While doing this, hold the pipeline by the hex wrench, otherwise it may bend or break.
5. Remove the return line.
6. Unscrew the nozzles with a socket wrench and arrange them in the installation order. If necessary, mark the nozzles with tape so that they can be reinstalled in their original positions.
7. Cover nozzle openings to prevent foreign bodies from entering.
8. Remove the injector gaskets. Gaskets must be replaced.
Attention! Never clean the nozzles or nozzle needles with a wire or file. Do not confuse the individual parts of the injectors with each other.
Installation
1. Clean the nozzle holes in the cylinder head and be sure to install four new heat-resistant gaskets. The indentation must face up. The arrow points towards the cylinder head.
2. Install the injectors and tighten to 70 Nm.
Attention! Overtightening the nozzles can cause the nozzles to deform, which in turn can lead to needle sticking or other problems.
3. Install the return line with four new gaskets and tighten the nuts to 45 Nm.
Attention! At the same time, keep the pipeline from turning with a key.
4. Install the high pressure fuel lines, tighten the union nuts to 25 Nm. At the same time, keep the fastener from turning.
5. Slightly loosen the union nuts on the high pressure fuel lines on all injectors.
6. Turn the engine over with the starter until fuel emerges from the high pressure lines.
7. Tighten the union nuts to the specified torque.
8. If necessary, prime the fuel system with a hand pump.