| 摘要 |
PURPOSE:To improve drivability and reduction in fuel consumption by detecting intake negative pressure when setting a fuel injection quantity on the basis of crankcase internal pressure fluctuations, and lowering a fuel pressure regulator the extent of fuel pressure against an increase of this detected intake negative pressure and thereby compensating the fuel injection quantity. CONSTITUTION:A pressure detector 66 is attached to a crankcase 18, detecting internal pressure P in a crank chamber 24, and a voltage signal (p) conformed to this detected value P is transmitted to a controller 72. An optimum fuel injection quantity is determined in response to this signal, thereby opening a solenoid valve of a fuel injection valve 44. A throttle valve 68 is opened or closed by lever operation of a driver, but negative pressure Q in an intake pipe 26 goes down with a decrease in opening of the throttle valve 68 and both diaphragms 48, 50 compress a spring 62, therefore the diaphragm 50 separates from a nozzle 64. Consequently, fuel in a fuel pressure chamber 58 flows back to a fuel tank 40 from the nozzle 64 causes a fuel pressure regulator 46 to lower fuel pressure, and thereby fuel pressure in the injection valve 44 goes down, decreasing the injection quantity. |
