single-point fuel injection nozzle means is responsible for only one fuel injection to each cylinder, the nozzle is not located on the intake pipe into the intake manifold before which the fuel injection amount according to the size of the size of the accelerator. Since the intake manifold of different lengths, Location distance, so the amount injected into each cylinder and the mixing time does not match the oil, thereby causing each of the cylinders are different working conditions.
1. The single point EFI noun
single-point fuel injection nozzle means is responsible for only one fuel injection to each cylinder, the nozzle is not located on the intake pipe into the intake manifold before that the fuel injection amount according to the size of the throttle angle. Since the intake manifold of different lengths, Location distance, so the amount injected into each cylinder and the mixing time does not match the oil, thereby causing each of the cylinders are different working conditions.
2. The single-point fuel injection characteristics
Usually a nozzle disposed at a single point EFI throttle body, the throttle body is arranged in front of the intake pipe. Single point of injection nozzle used in a small number of gasoline, and low cost. But after injection gasoline required by the intake manifold, carburetor and this is almost, so we can not give full play to the strengths of gasoline injection. From the viewpoint of cost and maintenance, practical advantageous over single point injection carburetor. Single point of injection without using the float chamber, the pressure required to press the amount of injected fuel can be, and from the control efficiency, precision and control stability control point of view than the carburetor good performance.
Since the single point injection injector is disposed above the throttle valve, can only improve the atomization and heating the wall temperature at the throttle improve the degree of evaporation of fuel, but it is difficult to ensure that the throttle valve to the intake It is not formed on the wall section of the door or oil film, and therefore have a significant impact of the intake manifold of the mixture gas transmission and distribution, can be difficult to achieve and maintain a desired air-fuel mixture distribution in all conditions.
However, single point injection structure is simple, reliable, easy to maintain. One very significant advantage is that a single point of injection is disposed above the throttle valve, a high velocity gas flow directly to the intake duct injection, since there is low pressure (flow rate inversely proportional to pressure), only the injection 0.1 MPa low pressure spray can, and multi-point injection will have to work until at 0.35MPa, which means that single-point injection system can reduce the requirements for electric fuel pump, saving costs. However, emission standards and fuel economy is not a single point and multi-point EFI EFI is now also slowly being eliminated.