The invention relates to a method for monitoring at least one exhaust gas turbocharger (ATL) of a large internal combustion engine (BKM), comprising at least one compressor (1a) and one exhaust gas turbine (1b) arranged on the same shaft as the compressor, wherein the current pressures (p.sub.1, p.sub.2) upstream and downstream of the compressor (1a) and the current temperatures (T.sub.1, T.sub.4) upstream of the compressor (1a) and upstream of the exhaust gas turbine (1b) are measured. In order to monitor an exhaust gas turbocharger effectively and as simply as possible, the current pressures (p.sub.4, p.sub.5) upstream and downstream of the exhaust gas turbine (1b), the current temperatures (T.sub.2, T.sub.5) downstream of the compressor (1a) and downstream of the exhaust gas turbine (1b), and the rotational speed (n.sub.A) of the exhaust gas turbine (1b) are measured, preferably continuously, the efficiencies (.sub.) of the compressor (1a) and of the exhaust gas turbine (1b) are calculated from the measured data, and a diagnostic algorithm is started when a worsening of the efficiency (.sub.TV, .sub.T) of the compressor (1a) and/or of the exhaust gas turbine (1b) is detected or after a defined time interval has elapsed.

Methods are provided for engine coolant system diagnostics. In one example, engine coolant system malfunction is indicated based on an engine coolant temperature inference model, whereas in another example engine coolant system malfunction is indicated based on a time-based monitor, where the inference model is enabled at ambient temperatures above a predetermined threshold, and where the time-based monitor is enabled at ambient temperatures below the predetermined threshold. In this way, accurate engine coolant system diagnosis may be accomplished under ambient temperature conditions wherein the engine coolant temperature inference model may be compromised.

A method for detecting a fault during operation of an internal combustion engine having manifold injection and direct injection; the internal combustion engine being controlled in two different combustion cycles, in each instance, for introducing a fuel quantity and a corresponding air quantity into a combustion chamber of the internal combustion engine, with different distributions of the fuel quantity to the manifold injection and the direct injection in the two combustion cycles; for each of the two combustion cycles, a value of a ratio of the air quantity introduced into the combustion chamber to the fuel quantity introduced into the combustion chamber being ascertained; and if at least one of the two values differs from a corresponding comparison value by more than a first threshold value, a type of fault during operation of the internal combustion engine being deduced in light of the difference.

The invention relates to a control method for controlling a fuel injection system (10) of an internal combustion engine, wherein, wherein, in a fault situation of the fuel injection system (10), a camshaft angle of a camshaft (34) which drives a pump piston (32) of a high-pressure fuel pump (14) of the fuel injection system (10) is adjusted such that an injection time (tI) of injector valve (42) which injects the fuel from the fuel injection system (10) into a combustion chamber of the internal combustion engine lies in a pressure trough (50) of a pressure oscillation in a high-pressure region (16).

Systems and methods for estimating when an engine event occurs is described. The system includes a controller configured to receive a first signal from at least one knock sensor coupled to a combustion engine, receive a second signal from at least one engine crankshaft sensor coupled to the combustion engine, transform the first and second signals into a plurality of feature vectors using a multivariate transformation algorithm, determine an expected window of an engine event with a statistical model, center a segment of the plurality of feature vectors around the expected window, estimate, using the statistical algorithm, a time in the expected window corresponding to when the engine event occurred, and adjust operation of the combustion engine based on the time.

An estimation unit calculates an estimated value of oxygen concentration in an exhaust passage on the basis of a target injection amount of a fuel injection valve and an air intake amount of an engine. A first determination unit determines the relationship of a detected value to the estimated value of the oxygen concentration, in both a fuel-injecting state and a non-fuel-injecting state. For each of a plurality of cylinders, a second determination unit acquires crankshaft angular acceleration during the expansion strokes of the cylinders in the fuel-injecting state, and determines the relationship of each angular acceleration to the average value of all of the angular accelerations. An abnormality determination unit determines whether or not there is an abnormality in an engine system on the basis of the determination results of the first and second determination units.

A system may include at least one engine bank including a plurality of fuel injectors. At least one exhaust temperature sensor is coupled to the engine bank(s). The exhaust temperature sensor(s) is configured to output at least one temperature signal regarding an exhaust temperature of the engine bank(s). A traction system is configured to output at least one electrical signal related to a power output of a vehicle. A control unit is coupled to the exhaust temperature sensor(s) and the traction system. The control unit is configured to receive the temperature signal(s) and the electrical signal(s). The control unit is configured to determine a mechanical and electrical health of the plurality of the fuel injectors by determining a temperature differential value of the temperature signal(s) and a power differential value related to the electrical signal(s), and analyzing a combination of the temperature differential value and the power differential value.

Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, operation of a port fuel injector is deactivated in response to an indication of reduced performance of a direct fuel injector so that degradation of the direct fuel injector may be reduced.

A method for recognizing a state change of a fuel injector of an internal combustion engine, in which fuel from a high-pressure accumulator is injected into a combustion chamber with the aid of the fuel injector. A value that is representative of a static flow rate of fuel through the fuel injector is ascertained. A state change of the fuel injector is deduced when the representative value differs from a comparative value by more than a first threshold value.

A safety system for 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 system is implemented as a wiring harness disposed exclusively on the engine which simultaneously disables one or more ignition coils and prevents 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 system 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.