1、 Sensors used in electronically controlled fuel injection engines

1. Intake pressure sensor: it reflects the change of absolute pressure in the intake manifold and provides a reference signal for ECU (engine electronic control unit) to calculate the fuel injection duration; Domestic Audi 100 car (V6 engine), Santana 2000 car, Beijing Cherokee (25L engine), Toyota Crown 3.0 car, etc. all use this pressure sensor. At present, semiconductor varistor air inlet pressure sensor is widely used< br />
2. Air flow sensor: measure the amount of air inhaled by the engine and provide it to the electronic control unit (ECU) as the reference signal of fuel injection time; According to different measurement principles, it can be divided into four types: rotary vane air flow sensor (Toyota previa station wagon), Carmen vortex air flow sensor (Toyota Lexus LS400 car), hot wire air flow sensor (vg30e engine for Nissan Qianli carriage and Volvo B230F engine for domestic Tianjin Sanfeng bus tj6481aq4) and hot film air flow sensor. The former two are volume flow type and the latter two are mass flow type. At present, hot wire air flow sensor and hot film air flow sensor are mainly used< br />
3. Throttle position sensor: measure the opening angle of throttle and provide it to ECU as the reference signal for fuel cut-off, fuel / air ratio control and ignition advance angle correction; It has three types: switch contact throttle position sensor (Santana 2000 car and Tianjin Sanfeng bus), linear variable resistance throttle position sensor (Beijing Cherokee), and integrated throttle position sensor (domestic Audi 100 V6 engine)< br />

4. Crankshaft angle sensor: also known as crankshaft position sensor, it is used to detect the crankshaft and engine speed and provide it to ECU as the reference signal to determine the ignition timing and working sequence; There are three types: electromagnetic pulse crankshaft position sensor, Hall effect crankshaft position sensor (Santana 2000 car and Beijing Cherokee), photoelectric effect crankshaft position sensor. Different types of crankshaft position sensors have different control methods and control accuracy. Crankshaft position sensors are generally installed on the side of crankshaft pulley or sprocket, some on the front of camshaft, and some on distributor (Santana 2000 car)