Contents: Removal ⇓ Installation ⇓
Faulty injectors can cause severe detonation in the engine cylinders and, as a result, damage to the crankshaft main bearing shells. If signs of detonation occur, let the engine idle and loosen the union nuts securing the fuel lines to the fuel injectors one by one. If the detonation disappears when the union nut is loosened, this indicates a faulty injector.
A faulty injector can be determined by successively loosening the union nuts and at fast idle speed (when the engine warms up). If after loosening the union nut the engine crankshaft speed does not change, this indicates a faulty injector. The injector can be tested on a bench that creates a pressure of 135 bar.
The first signs of injector malfunction appear as follows:
- false ignitions in engine cylinders;
- detonation in one or more engine cylinders;
- engine overheating;
- decrease in engine power;
- excessively strong black exhaust;
- increased fuel consumption.
Removal
Disconnect the cable from the negative battery terminal.
Using cleaner or diesel fuel, carefully clean the outside of the fuel supply and return lines.
Caution! Disconnecting the negative battery cable will erase the memory of electronic memory devices, such as the radio receiver code.
Figure 4.25. Location of union nuts for fastening pipes to the high-pressure fuel pump and fuel injectors
Loosen the union nuts on the high-pressure fuel pump and injectors and remove the tubes as a set (figure 4.25)
Caution! Do not disturb the bending shape of the tubes.
Remove the fuel injectors and lay them out in the same order they were installed on the engine.
Caution! No dirt must enter the combustion chambers through the injector openings.
Each fuel injector hole contains a wave gasket and washer that must be replaced.
The injector needles must not have knocked out or rough seating areas. Use a wooden spatula to remove carbon deposits from the injectors.
Caution! Never clean the injector or needle with wire, a file, or sandpaper. Do not confuse the parts of different injectors.
Installation
Figure 4.26. Installing the fuel injector: 1 – washer; 2 – fuel injector; 3 – washer; 4 – corrugated gasket
Important! Install four new wave gaskets and four washers on the injectors (figure 4.26).
Attention! Observe the installation position of the corrugated gasket.
Screw in the fuel injectors and tighten them to 65 Nm.
Caution! Tightening fuel injectors to a torque greater than specified may result in deformation, needle sticking, and other damage.
Figure 4.22. Loosening the union nut securing the fuel line to the fuel injector to remove the air lock
Connect the fuel return pipes with new gaskets and secure with nuts, tightening them to a torque of 25 N·m (see Figure 4.22).
On all injectors, slightly loosen the union nuts securing the high-pressure pipes.
Turn the engine crankshaft with the starter until no air bubbles come out of the fuel lines. Tighten the union nuts to the specified torque.
Install the air supply pipe and resonator duct.
Connect the cable to the negative terminal of the battery.
If you have a clock, set the time and enter the radio security code.