how to install a tachometer on a diesel engine

• 2022-05-05

The speed is transmitted through the diesel engine speed sensor installed on the automobile cylinder block. The principle is as follows: there is a disc on the crankshaft, which rotates with the crankshaft, and there is a gap on the crankshaft. The crankshaft sensor is an electromagnetic induction coil, which can detect the gap on the crankshaft, and then transmit it to the instrument panel through the linear speed of the crankshaft sensor.

Although there are no pictures, the speed sensors of most cars are installed on the gearbox. There are two kinds: inductive (electric wire) and mechanical (meter cable). His speed signal adopts the neutral point voltage signal of the generator. There are B + D + and N + on the generator, that is, the output of the neutral point. The multimeter will have different voltage changes at different speeds. Generally, there will be 6-12V voltage changes. This voltage signal is adopted by the tachometer.

The method is to turn on the ignition switch, press the start button, put the starting motor into operation, drag the diesel engine into the starting condition, and pay attention to the change of the pointer of the engine tachometer at the same time. If the pointer of the engine tachometer can rise up, it means that the engine tachometer can be put into operation. It means that the charging winding, triggering winding and electronic igniter of the ignition system are basically normal, and the ignition system can not produce high-voltage spark fault to the ground. Therefore, it can be analyzed and judged that the ignition coil and its connecting line in the ignition system are faulty, and the ignition coil and its connecting line can be checked first Inspection will quickly eliminate the fault. If the engine tachometer cannot be put into operation, it indicates that there is no high-pressure fire fault in the ignition system, and the fault range is relatively large. However, first of all, the possibility of ignition coil failure can be eliminated. At this time, the connection between the electronic igniter and the cable harness connector can be disconnected, and the charging winding, trigger winding, ignition switch, ignition coil and grounding wire terminal in the cable harness connector can be detected with a multimeter, so that the suspected points can be quickly found and the fault can be eliminated smoothly.