1. With a sliding block
About EFI fuel-efficient car or neutral slide with a sliding block fuel debate there are many related article introduces a lot. Considered neutral slide fuel remarks are generally older drivers, in their view, with a sliding block when the engine speed is high, definitely consume more fuel, and after picking neutral, idle speed drops, should speed ratio when more provinces. And think with a sliding block more fuel-efficient remarks, it is considered the engine with a sliding block of time, we will not continue to fuel injection, and thus more fuel efficient than idling in neutral. That statement is correct? Today we will analyze analysis.
Many older drivers are open past carburetor car, based on their understanding of performance from the engine, as well as the actual driving experience, fuel-efficient indeed neutral slide. Why the old carburetor fuel-efficient car neutral slide it? Let’s start with the point of view of the structure of the carburetor, the carburetor float chamber, jet, nozzle, hose and throttle so on. The float chamber from the fuel pump gasoline storage sent by the float to control the level of the oil, and an air inlet in communication with the atmosphere above the carburetor, so that the same float chamber pressure and atmospheric pressure to ensure that oils is stable.
When the engine is started, the downward movement of the piston in intake stroke, a great suction force is generated, combined with the special design of the throat (crude intermediate thin two), the air stream flowing at this time is accelerated at the throat , the pressure is also reduced at the throat, the throat when the pressure at less than atmospheric pressure, i.e. a pressure difference between the pipes and the float chamber from the discharge pipe under the effect of vacuum pressure of gasoline, at this time, there are high-speed air stream at the throat through the discharge airflow blown instantly gasoline, mist particles are formed, i.e., to form a combustible gas mixture, the final throttle valve, an intake duct, a combustion chamber for combustion into the cylinder work.
When the engine is at idle, the throttle valve is in a closed state, then the engine speed is reduced, the reduced air velocity at the throat, the vacuum pressure decreases, the amount of gas discharged from the nozzle will also becomes smaller, when the engine is most fuel-efficient state. When with a sliding block,While the throttle valve is in a closed state, the engine speed is very high, in the throat of the air velocity is faster than when the neutral condition, so that a greater vacuum pressure, under the effect of vacuum pressure, the amount of fuel discharged from the nozzle than the amount of fuel injection during idling is much higher. So when the carburetor fuel-efficient than cars with a sliding block in the neutral slide.
EFI car carburetor fuel supply system with a completely different car, car carburetor fuel injection is drawn into the intake port by a passive, so that the air flow in the throat is faster inhalation the more fuel, and the fuel injection amount EFI car is actively controlled, is controlled by an ECU (electronic control unit), by a throttle position sensor, an engine crankshaft speed sensor, air flow meter, a crank phase sensor means for detecting the like, and the detected information is analyzed by the ECU, each processing the last command the operation of the actuator.
ECU primarily by an engine throttle position sensor to determine the engine operating state is in what is idle condition, part or full load condition conditions, but also to determine the load condition of the engine through the crankshaft rotational speed sensor. In order to analyze the fuel injection quantity is increased or decreased amount of fuel injection. When EFI car with a sliding block, the ECU based on a throttle position sensor for the throttle valve is closed at this time is determined idle condition, and is determined by the rotational speed of the crankshaft when the engine speed sensor, the respective sensor signal in accordance with finally fed back for analysis Analyzing, reduced instruction to make fuel injection.
an extreme case, the fuel injection amount will be very low, low to view data from the trip computer, an instant fuel consumption at this time is zero hundred kilometers. Clearly, this state than neutral idle time to fuel-efficient, because when neutral is still needed to maintain the operation of the engine through the fuel injection. Note that both the carburetor or fuel injection, neutral slide is very dangerous.
Although the neutral slide carburetor fuel-efficient car, but the danger of such an engine at this time is larger than the EFI car, because this purely mechanical fuel supply system, the probability of an engine stall than EFI car It is much greater. We know that the engine flameout would mean the loss of brake power, is very dangerous. The EFI car? Neutral slide equally dangerous, and so will increase the burden on the brakes, and fuel economy we care about the most, there is no advantage at all. So no matter the type of engine, we have to bear in mind, should not neutral slide.