Nissan Motor Company Limited

Kenichi Gotoh

Shinsuke Nakazawa

Toshio Takahata

Atsushi Iochi

Hiroshi Kuriki

A first passage provided with a first valve for guiding vaporized fuel from a fuel tank into a canister, and a second passage provided with a second valve connecting this canister with an intake pipe downstream or a throttle, are provided. A pressure detecting mechanism is provided between this first valve and second valve, and a third valve is provided for leading fresh air into the canister. When the engine running condition satisfies a predetermined positive pressure test condition, the second and third valves are closed and the first valve is opened. In this state, the presence or absence of a leak is determined from the pressure detected by the pressure detecting mechanism. In other words, it is determined for example that the fuel tank has no leak if the pressure rises above a predetermined value.

Leak test system for vaporized fuel treatment mechanism

A diagnostic system for an idle speed control valve is constructed to determine abnormality of the idle speed control valve by detecting a variation in an intake air amount produced upon forced opening and closing operation of the idle speed control valve.

Growing community of inventors

Zama, Japan

Kenichi Gotoh