| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a conventional abnormality diagnostic device cannot determine whether or not a viscosity abnormality occurs in fuel to be used during pressurization supply of the fuel to an engine mounted on a vehicle from a supply pump (during a fuel pressure-feeding period).SOLUTION: An abnormality diagnostic device applied to a common rail type fuel injection system mounted on an engine for vehicle traveling estimates viscosity (μ) of fuel to be used, on the basis of a ΔP-μ map indicating a relationship between fuel pressure rise amount (ΔP) detected by a fuel pressure sensor and the viscosity (μ) of the fuel to be used for a pressure-feeding period in which the fuel to be used is pressurized and supplied from a supply pump 4. When an estimated value of the viscosity (μ) of the fuel to be used is deviated from a predetermined standard range, a determination that a property abnormality occurs in the fuel to be used is made. Thus, while the common rail type fuel injection system is mounted on the engine for vehicle traveling, the viscosity of the fuel to be used can be measured.SELECTED DRAWING: Figure 6 |
