An engine fuel delivery system includes a fuel pump having a pumping chamber to increase fuel pressure and a closeable inlet valve, and a fuel rail to communicate pressurized fuel received from the fuel pump to at least one engine cylinder. The engine fuel delivery system also includes a controller programmed to issue a control signal to periodically close the inlet valve to generate a setpoint fuel pressure within the pumping chamber. The controller is also programmed to adjust a control signal gain value in response to deviation in an outlet fuel pressure relative to the setpoint fuel pressure. The controller is further programmed to issue a warning message in response to the control signal gain being adjusted by more than a predetermined threshold from a calibrated gain value.

An apparatus includes a processing circuit structured to receive a first signal indicative of an upstream air-fuel equivalence ratio from a first sensor positioned upstream of an intake of a catalyst, receive a second signal indicative of a downstream air-fuel equivalence ratio from a second sensor positioned downstream of the intake of the catalyst, determine an actual oxygen storage capacity of the catalyst based at least in part on the received first signal and the received second signal, compare the actual oxygen storage capacity to a maximum storage capacity, and provide a fault signal in response to the actual oxygen storage capacity exceeding the maximum storage capacity. The apparatus also includes a notification circuit structured to provide a notification indicating that the second sensor is faulty in response to receiving the fault signal.

A construction machine management system in which a failure analysis or a failure-omen diagnosis of a machine body can be performed with a high degree accuracy and at a low cost is provided. In a machine body group of construction machines including at least one representative machine body having an engine control unit that detects a cumulative stress value of a diesel engine of the construction machine and a crankcase pressure sensor that detects a crankcase pressure, and at least one general machine body that has an engine control unit but does not have a crankcase pressure sensor, a center server performs a diagnosis of an omen of a failure state regarding the crankcase pressure of the general machine body based on correlation information between the cumulative stress value and the crankcase pressure obtained from the representative machine body and the cumulative stress value of the general machine body.

Disclosed herein are embodiments of systems and methods for determining the state of health of a generator battery set and its ability to supply generator starter motor with start-up energy by capturing a profile of voltage across terminals of the battery during a supply of electrical energy from the battery to the starter and comparing the captured voltage profile to a reference voltage profile to determine if a difference between the captured voltage profile and reference voltage profile exceeds an acceptable amount.

Various methods and systems are provided for a multi-fuel capable engine. The system includes a liquid fuel system to deliver liquid fuel to an engine, a gaseous fuel system to deliver gaseous fuel to the engine, and a control system. The control system, during a gaseous fuel system test mode, controls the liquid fuel system and the gaseous fuel system to deliver the liquid fuel and the gaseous fuel to the engine over a range of engine operating points, and indicate degradation of the gaseous fuel system based on engine output at each of the engine operating points.

Methods and systems are provided for determining a type of spark plug fouling. In one example, a method may include differentiating spark plug fouling due to soot accumulation from spark plug fouling due to fuel additive accumulation based on a current on a control wire of the spark plug following application of a dwell command. Further, exhaust oxygen sensor degradation and/or exhaust catalyst degradation may be determined based on switching frequencies of one or more exhaust oxygen sensors and the type of spark plug fouling.

A driver inducement method and a driver inducement system for a vehicle that induce a driver to replenish a urea considering a urea level in a urea tank and an actual vehicle speed are disclosed. The driver inducement method may include: calculating a first residual travel distance according to a urea level and an average urea consumption if an engine is started; calculating a final residual travel distance based on the first residual travel distance according to the urea level and the average urea consumption and a second residual travel distance according to the urea level and a vehicle speed, if the first residual travel distance according to the urea level and the average urea consumption is smaller than a threshold distance; and limiting an engine output according to the final residual travel distance.

A misfire detecting system for an engine of a vehicle that detects a misfire of the engine is provided. The system includes a sensor configured to detect a wheel speed of the vehicle, a load adjustment device configured to adjust a load of the engine, and a processor. The processor determines whether a wheel slip has occurred by examining whether a change rate of the wheel speed is equal to or greater than a determination reference value, when determining whether the wheel slip has occurred, limits a determination of the misfire of the engine by adjusting the determination reference value higher or lower based on corresponding increases or decreases in a requested load, by applying the adjusted determination reference value, determines that wheel slip has occurred, and based on the wheel slip determination, determines that the misfire has occurred.

A system includes an electronic fuel injection system of an engine, the electronic fuel injection system including an electronic governor control unit for controlling various functions of the engine.

In order to prevent an abnormal combustion due to oil, a restriction region (B) is designated on a low-speed and high-load side of an internal combustion engine (1), and an opening of throttle valve (12) is restricted so that an engine operating condition is not observed within the restriction region (B). A predetermined designated inspection region (A) is set so as to include the restriction region (B), and it is judged whether or not the abnormal combustion actually occurred when the internal combustion engine (1) is running within the designated inspection region (A). If the abnormal combustion was detected, the restriction region (B) is expanded, meanwhile, if the abnormal combustion was not detected, the expanded restriction region (B) is gradually decreased. If the abnormal combustion occurred at a shorter interval than a threshold value, the restriction region (B) is expanded at once to a predetermined size.