It is often said that the gasoline engine is made up of two big organizations and five big systems. That is, the two mechanism is the crank link mechanism and timing mechanism. The five system is cooling system, lubrication system, fuel supply system, ignition system, starting system. We look at the types of gasoline engines: Carburetor engines, mechanical jet engines, multi point injection electronically controlled engines, direct injection electronically controlled engines, rotor engines, hybrid engines and so on. In fact, the two major institutions and the five major systems of gasoline engines are gasoline engines that use piston reciprocating - cam - valve four - stroke five process thermal cycle. Its fuel supply way is carburetor gasoline engine. That is, the carburetor engine is simply said. In addition to the carburetor engine, the mechanical injection, the multi point injection electronic control, the direct injection electronic control engine are all the same piston reciprocating, one gas cam four stroke five process Otto thermal cycle gasoline engine, but the fuel supply mode is the mechanical injection type, the multi point injection electronic control type, Direct injection of electronic control type. Then, what is the difference between the composition of the electronic controlled engine (i.e. multi-point injection and direct injection electronically controlled engine) and carburetor type engine? Here we will not discuss other types of engine components. The electronically controlled engine consists of three mechanisms, three systems, five controls, and three working conditions. Let's take a good look at what constitutes each part. If it is still considered as a combination of two institutions and five systems, it is totally wrong. The cognition of the electronically controlled engine is not correct. Diagnosing the fault of the electronically controlled engine is necessarily troublesome or unable to solve the complex fault. The following is a detailed description of the components of the electronically controlled engine and the specific components. One, three institutions, 1. crank and connecting rod mechanism: the crankshaft flywheel group, the piston connecting rod group and the cylinder body one crankcase. That is, the structure of the lower box. 2. valve train: composed of valve group, cam drive group and cylinder head. That is, the upper box structure. The valve group is composed of a valve, a valve seat, a conduit, a spring and an oil seal. The cam drive group has three kinds of structure. They are direct drive, rocker arm and rocker tappet. 3, the timing mechanism: the timing transmission mechanism. That is, the front end cover structure. It also has three transmission modes, namely, gear type, chain type and transmission belt type. Take the transmission belt as an example, its composition is generally: crankshaft timing wheel, cam timing wheel, idler wheel, tension wheel, regulator, transmission belt and so on. The two or three system 1. cooling system: cooling cycle system. It is composed of centrifugal pump, thermostat, radiator, small circulating pipe, upper and lower pipes, water jacket (cylinder head). 2. lubrication system: Lubrication circulation system. It is composed of oil pan, filter, oil pump, filter, safety valve, bypass valve, throttle valve and so on. 3. crankcase ventilation system: lower exhaust and clean circulation system. Generally it consists of PCV valve, throttle front and rear pipes, valve chamber cover, oil and gas separator and so on. Three, five control 1. air supply systems: air filters, intake ports, throttle bodies, intake manifolds, intake manifolds. 2. fuel supply system: oil tank, filter, fuel pump, filter, oil rail, fuel injector, fuel pressure regulator, return pipe. To remind readers, the fuel supply system is different from the fuel supply system. 3. ignition system: spark plug, high voltage wire, ignition coil, ignition amplifier (distributor). Remind the reader that the ignition system is different from the ignition control system. 4. exhaust and purification system: exhaust manifold, exhaust pipe, muffler, EGR, fuel evaporation, three Yuan catalysis, oxygen control, two air injection and so on. 5. electronic control system: all kinds of sensors from air supply system (air flow meter, throttle position, water temperature, air temperature signal). Time signal (crankshaft speed, crankshaft position, camshaft position). Feedback signal (oxygen signal, detonation signal). Electronic control unit. An idle motor (idle motor). Oil pump motor. Spray nozzle solenoid valve) etc. Four, three working conditions (control) (attention: to the engine system is working condition, to the user is manipulated) 1. starting conditions: starter and related control circuits and components. 2. idle speed: idle motor or throttle and related control circuits and components. 3. driving conditions: throttle pedal, drawing mechanism, throttle body, and related control circuits and components. The above is based on facts. Each component or part and system is visible and touches. Why do we say that the electronically controlled engine is the two organization and the five system? The two organization and the five system are carburetor engines. Do not make carburetor engine as an electronically controlled engine, is there no development of engine structure and no change? The composition of the engine is not the same. I hope you should learn all knowledge critically and not be superstitious about book knowledge.