A lower limit setting portion of a fuel pump control system sets a lower limit value depending on an engine operating mode. For example, it sets a duty ratio of 0% as the lower limit value, when the engine operating mode is in a STOP mode in a turned-on condition of an ignition switch. A duty-ratio calculating portion carries out a feedback control in order that an actual fuel pressure comes closer to a target fuel pressure by use of the lower limit value and calculates a duty ratio for driving a fuel pump by the feedback control. An abnormal condition determining portion determines an abnormal condition based on the duty ratio and pump current. The abnormal condition determining portion further determines based on a remaining fuel amount whether the abnormal condition is caused by a disconnection or whether the abnormal condition is caused by an idling operation of the fuel pump due to fuel shortage.

Methods and systems are provided for diagnosing an exhaust waste-gate valve via an electric boost assist motor of an electric turbocharger. Degradation of the waste-gate valve is inferred based on the motor torque profile of the motor after commanding the waste-gate valve to an open or closed position on a torque transient. Deviation of the motor torque profile from the expected profile is used to infer if the valve is stuck open or closed, and actions are taken accordingly.

Systems and methods (e.g., a method for controlling and/or operating a compressor) are provided that includes the steps of monitoring a crankcase pressure of a first compressor; analyzing the monitored crankcase pressure that includes calculating an average of the crankcase pressure over a time period and comparing the average of the crankcase pressure over the time period to a nominal crankcase average pressure; identifying a condition of the first compressor based on the analysis of the monitored crankcase pressure; and adjusting operation of a second compressor to compensate for the first compressor in response to identifying the condition of the first compressor based on the analysis of the monitored crankcase pressure. (The method may be carried out automatically or otherwise by a controller).

The present invention provides a device and method for detecting a misfire in an engine, the device being provided with: a rotation speed sensor (43) as a supercharger rotation speed measurement unit for measuring a rotation speed (Nt) of a supercharger (23); a misfire index calculation unit (51) that calculates a misfire index (Yt) from a degree of change in the rotation speed (Nt) of the supercharger (23), the rotation speed being measured by the rotation speed sensor (43); and a misfire determination unit (52) that determines a misfire in an engine (10) when the misfire index (Yt) calculated by the misfire index calculation unit (51) exceeds a pre-set determination value (D).

A method for ascertaining the movement of an armature of an electric intake valve, an electrical variable of the electric intake valve being controlled to predefined values with the aid of a two-position controller, a characteristic point in time of the movement of the armature being ascertained based on the switching behavior of the two-position controller.

Methods and systems are disclosed for operating an engine that includes fuel injectors that supply fuel to cylinders of the engine. According to the methods and system, variation of individual fuel injection amounts injected by a sole fuel injector are determined so that it may be determined if individual fuel injector variation may be contributing to engine air-fuel ratio variation.

A failure diagnosis device for an ignition circuit, comprising: an ignition plug; an ignition coil; a capacitor series connection including a high side capacitor and a low side capacitor; a switching-element series connection including a high side switching element and a low side switching element; an inter-terminal voltage detection unit for detecting an inter-terminal voltage of the capacitor series connection; an intermediate voltage detection unit for detecting an intermediate voltage at the connection point of the high side capacitor and the low side capacitor; and a determination unit for determining a failure location of the ignition circuit based on at least one of the inter-terminal voltage and the intermediate voltage.

A method for manufacturing engine powered machinery having a fuel cut functionality to promote more rapid shutdown of the rotating parts of the engine powered machinery. In one aspect, the method is implemented by assembling a wiring harness disposed exclusively on the engine which are configured to simultaneously disable one or more ignition coils and prevent a fuel-air mixer from supplying a mixture of air and fuel to the engine upon activation of a safety switch. In alternate aspects, the method further comprises a stator brake which is activated by the safety switch to provide additional braking torque on the engine. These features bring the machinery to a rapid halt, further enhancing safety.

A fuel injector system includes an injector body having a proximal end and a distal end, the injector body defining a nozzle having an outlet. The injector system includes a spill valve fluidly connected to the outlet and having a spill valve member movable between an open position and a closed position. The injector system includes a control valve including a control valve member movable between an open position and a closed position. The injector system includes a check valve fluidly connected to the outlet, the control valve including a check valve needle movable between an open position and a closed position. The injector system also includes an electrical monitoring circuit configured to output a signal indicative of at least one of the open position or the closed position of the spill valve member.

Methods and systems are provided for diagnostics of an exhaust tuning valve during vehicle-off conditions. In one example, the engine may be reverse rotated, unfueled while the position of the exhaust is varied and an intake air flow is estimated at each position of the exhaust tuning valve. The exhaust tuning valve may be diagnosed based on a change in air flow with the variation in the position of the exhaust tuning valve.