Patent ID: 7322345

Claim:
A stuck-open failure detection system for a gas-fuel injection valve adapted to inject fuel into a combustion chamber of an engine or to inject gas-fuel into an intake passage, comprising: a shutoff valve interposed in a fuel supply passage fluidically connected to said gas-fuel injection valve, at a position upstream of said gas-fuel injection valve, and adapted to supply gas fuel to said gas-fuel injection valve in its open state; an open/close controller for controllably opening and closing said shutoff valve; a pressure detector for detecting a pressure in a region of said fuel supply passage between said gas-fuel injection valve and said shutoff valve; and a stuck-open failure detector for detecting a stuck-open failure that said gas-fuel injection valve is stuck in the open state, based on a pressure change detected by said pressure detector, wherein: said open/close controller is operable, in response to an operation for starting the engine, to open and said shutoff valve immediately after an ignition switch has been turned ON and then close said shut off valve after a lapse of a first given time, and said stuck-open failure detector is operable to detect said stuck-open failure of said gas-fuel injection valve disposed at a position downstream of said shutoff valve, if a pressure change, which is produced between a first moment that said shutoff valve is closed and a second moment that a second given time has lapsed from said first moment, is larger than a predetermined value.