A control device of a general-purpose engine which can continue operation of a working machine even when an operation management unit of the working machine has failed. The control device includes an engine control unit that controls the general-purpose engine based on a command from the operation management unit managing an operating state of the working machine, a communication interface for communicating with an external device; a management program acquisition unit that acquires a management program that is used by the operation management unit to manage the operating state, from the external device through the communication interface and stores the acquired management program in a storage medium, and an operation management substitute unit that manages the operating state of the working machine in place of the operation management unit in accordance with the management program when a failure of operation management unit is detected.

An air flow measurement device that measures an air flow rate based on an output value of a sensing unit attached in an environment in which air flows, the air flow measurement device is provided. The air flow measurement device may calculate an average air amount, which is an average value of the air flow rate, from the output value. The air flow measurement device may calculate a pulsation maximum value, which is a maximum value of the air flow rate, from the output value.

A system and method for limiting a speed of a vehicle is disclosed. The vehicle includes an ECU in communication with and configured to control the engine. The ECU has a plurality of pins, a jumper plug connected to the plurality of pins, and a cap selected from a group of caps, each of which is configured to create a different limit circuit when installed on the jumper plug. The ECU is configured to limit the speed of the vehicle to a predetermined speed when the limit circuit is detected by the ECU based on the detected cap. The ECU, jumper plug, and cap are covered by a cover secured to the frame of the vehicle by fasteners that require a tool to remove.

An air flow measurement device that measures an air flow rate based on an output value of a sensing unit attached in an environment in which air flows, the air flow measurement device is provided. The air flow measurement device may calculate an average air amount, which is an average value of the air flow rate, from the output value. The air flow measurement device may calculate a pulsation maximum value, which is a maximum value of the air flow rate, from the output value.

An engine includes a first injection valve, which is one of port and direct injection valves, and a second injection valve, which is the other. When operating only the first injection valve based on a base injection amount, which has been corrected using a feedback operation amount and a first learning value, an air-fuel ratio control apparatus updates the first learning value and determines that the first learning value has converged on condition that a correction ratio of the base injection amount is not more than a predetermined ratio. When the first and second injection valves are being operated, the apparatus updates a second learning value for the second injection valve on condition that the first learning value has converged and the ratio of the injection amount of the second injection valve is not less than a specified value.

Methods and systems for operating an engine with split lambda modes are provided. At least one example method comprises, calculating a stoichiometric torque output of the plurality of cylinders; then applying one or more lean torque modifiers for every lean cylinder of the one or more non-stoichiometric cylinders to the stoichiometric torque output to calculate a lean torque output. In at least one example, one or more rich torque modifiers for every rich cylinder of the one or more non-stoichiometric cylinders may be applied to the stoichiometric torque output to calculate a rich torque output. Further, the lean torque output and the rich torque output may be summed to calculate a total engine torque output.

The speed of a turbocharger may be estimated using data from sensors that are readily available in most engine management systems. In some cases, a pressure measurement from a MAP sensor may be used, in combination with one or more computational models, to provide an efficient, lower cost estimate of turbo speed that can be used to control operation of the engine and/or the turbocharger.

Methods and systems are provided for accurately estimating intake aircharge based on the output of an intake oxygen sensor while flowing EGR, purge, or PCV hydrocarbons to the engine. The unadjusted aircharge estimate is used for engine fuel control while the hydrocarbon adjusted aircharge estimate is used for engine torque control. A controller is configured to sample the oxygen sensor at even increments in a time domain, stamp the sampled data in a crank angle domain, store the sampled data in a buffer, and then select one or more data samples corresponding to a last firing period from the buffer for estimating the intake aircharge.

A system and method for limiting a speed of a vehicle is disclosed. The vehicle includes an ECU in communication with and configured to control the engine. The ECU has a plurality of pins, a jumper plug connected to the plurality of pins, and a cap selected from a group of caps, each of which is configured to create a different limit circuit when installed on the jumper plug. The ECU is configured to limit the speed of the vehicle to a predetermined speed when the limit circuit is detected by the ECU based on the detected cap. The ECU, jumper plug, and cap are covered by a cover secured to the frame of the vehicle by fasteners that require a tool to remove.

A method of operating a fuel injector includes determining a fuel pressure and a total fuel mass M.sub.TF to be injected per combustion cycle, defining first and second pulse widths PW.sub.1 and PW.sub.2 corresponding to first and second commanded fuel masses CM.sub.1 and CM.sub.2 wherein CM.sub.1+CM.sub.2=M.sub.TF, actuating the injector for the first and second pulse widths, detecting an opening delay for the injector, and storing the opening delay. The method may further include increasing PW.sub.1 and decreasing PW.sub.2 by a predetermined amount, repeating selected steps until PW.sub.2 is less than or equal to a predetermined minimum pulse width, changing the fuel pressure by a predetermined pressure amount, cycling through selected steps until the fuel pressure reaches a predetermined target fuel pressure, and commanding the injector to open earlier than a normally commanded opening time by a lead time based on stored opening delay data.