Patent ID: 7080548
Filing Date: 2006-07-25
Classification: F02D,F02M

Abstract:
1. A diagnostic device of an evaporated fuel processing system for closing an evaporated fuel processing system including a fuel tank after introducing a negative pressure into the evaporated fuel processing system to execute a leak diagnosis of the evaporated fuel processing system, comprising: an internal pressure detection section for detecting an internal pressure of the evaporated fuel processing system; an intake pressure detection section for detecting an intake negative pressure of an inlet system; a control section for closing the evaporated fuel processing system at a closing timing wherein the internal pressure detected by the internal pressure detection section reaches a preset target pressure value when the negative pressure is introduced from the inlet system to the evaporated fuel processing system; a diagnostic section for comparing the internal pressure value at a diagnostic timing set to come after the closing timing with a preset criterion threshold value to execute the leak diagnosis of the evaporated fuel processing system; and a calculation section for variably setting the diagnostic timing based on the intake negative pressure value detected by the intake pressure detection section.