Note: Special precautions must be taken when servicing injectors. Remember that the actuation pressure of the injectors is very high and that serious injury may result from the jet from the nozzle coming into contact with exposed parts of the body. The authors of this manual recommend that all pressure tests on the system be performed by a qualified service station.
See the warnings provided 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) mileage of the car. Accurate diagnostics of the injectors condition, their major repairs 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 let it run at fast idle speed. Loosen the unions of each injector one by one, after placing a rag around them to collect the fuel that passes through. When the union of the defective injector is loosened, the detonation or excessive smoke that is occurring will stop.
Removal
Note: Do not allow dirt to enter the injectors under any circumstances. Do not drop the removed injectors, do not try to clean them with a needle.
1. Disconnect the negative cable from the battery.
2. Cover the generator with a clean cloth to protect it from spilled diesel fuel.
3. Carefully wipe the surfaces around the injectors and the nuts of their unions. Disconnect the return pipes from the injectors.
4. Wipe the surfaces around the nipple connections of the feed tubes and disconnect the latter from the injectors and the rear part of the injection pump (the tubes are removed as a single assembly). When loosening the coupling nut, hold the other half of the connector on the pump from turning with a second wrench. Remove the tube assembly from the engine. Immediately plug the open fittings to prevent dirt from getting into the system.
5. Using a 27mm deep socket, unscrew each injector from the cylinder head and remove them from the engine.
6. Remove and discard the heat-protective washers - they must be replaced during assembly.
Installation
1. Install new injector heat shield washers onto the cylinder head. Remember that the washers must be installed with the concave side down (towards the head).
2. Screw the injectors into their mounting seats 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 fasteners on the pipes.
4. Connect the return pipes to each of the injectors. Connect the battery and check the engine for proper operation.