Note. When servicing injectors, special precautions must be taken. Be aware that the trigger pressure of the nozzles is very high and if the jet from the nozzle hits exposed areas of the body, serious injury can result. The authors of this manual recommend that all pressure testing of the system be performed by a qualified workshop.
See the warnings in Section General information and precautions.
General information
Injectors are subject to wear during engine operation, and therefore their condition should be checked at least every 100,000 km (60,000 miles) car mileage. Accurate diagnostics of the condition of injectors, their overhaul and calibration should be left to specialists. The procedure for identifying defective injectors is described below (leading to detonation or excessive smoke).
Start the engine and run it at fast idle. Loosen the fitting connections of each of the injectors one by one, having previously overlaid them with rags to collect the leaked fuel. Loosening the fitting of a defective injector will stop the knocking or excessive smoke that occurs.
Removing
Note. Under no circumstances should dirt be allowed to enter the nozzles. Do not drop the removed nozzles, do not try to clean them with a needle.
1. Disconnect the negative cable from the battery.
2. Cover the generator with a clean rag to protect it from spilled diesel fuel.
3. Thoroughly clean the surfaces around the injectors and their union nuts. Disconnect the return pipes from the injectors.
4. Wipe the surfaces around the fitting connections of the supply pipes and disconnect the latter from the nozzles and the rear of the injection pump (tubes are removed as a single assembly). When giving the connection nut, hold the second half of the connector on the pump from turning with a second wrench. Remove the tube assembly from the engine. Seal open fittings immediately to prevent dirt from entering the system.
5. Using a 27 mm deep socket, unscrew each of the injectors from the cylinder head and remove them from the engine.
6. Remove and discard thermal washers - they must be replaced during reassembly without fail.
Installation
1. Install new injector heat shields on the cylinder head. Remember that the washers must be installed with the concave side down (to the head).
2. Screw the nozzles into their sockets in the head and tighten them to the required torque.
3. Connect the fuel pipes by tightening the union nuts to the required torque. Install all necessary clamps and clamps on the tubes.
4. Connect return tubes to each nozzle. Connect the battery and check that the engine is working properly.