Systems and methods for detecting at least one non-functional combustion chamber of an engine comprising a plurality of combustion chambers are described herein. In response to detecting a partial output power loss of the engine, one of the plurality of combustion chambers is assessed by monitoring an engine parameter indicative of an output power of the engine, determining whether a change in the engine parameter has occurred, when the change has occurred, determining that the combustion chamber is functional, and when no change has occurred, determining that the combustion chamber is non-functional and discontinuing fuel injection to the non-functional combustion chamber.

A combustion pressure sensor has a case member with a joint surface on the side of a tip end and in which an opening portion is provided. A joint surface of a pressure reception member on which a combustion pressure acts is brought into planar contact with the joint surface of the case member so as to block the opening portion. A welding portion joins the joint surfaces to each other. A piezoelectric element stored in the case member converts a pressing force based on the combustion pressure transmitted from the pressure reception member into a signal. On the side of one edge side in at least the one joint surface, the one joint surface is limited to a given depth of welding from the other edge side. A predetermined clearance portion is provided so as to form a predetermined gap with the opposite joint surface and a welding portion is provided which includes at least all the limited joint surface from the other edge side in the one joint surface.

A method of estimating a compressor inlet pressure for a turbocharger includes: measuring an ambient temperature of air flowing into the compressor; measuring a flow rate of the air into the compressor; measuring a boost pressure of the air from the compressor to an engine; determining a speed of a turbine of the turbocharger; defining a pressure ratio as the ratio of the boost pressure to the compressor inlet pressure; defining a function as the function of the compressor flow rate, the ambient temperature, the compressor inlet pressure and the turbine speed; and equating the pressure ratio and the function and recursively solving for the compressor inlet pressure.

Methods are provided for reliably self-testing a water injection system that injects water into the engine responsive to engine operating conditions such as knock, the water injection system refilled manually or via the collection of water on-board the vehicle. Responsive to a water injection error, learned based on a change in a defined set of engine parameters while ramping water injection during selected conditions, the presence of clogging in a water line may be determined. Based on a degree of clogging, subsequent water injection may be appropriately adjusted.

A method for predicting failure in a cylinder of a multi-cylinder engine is provided. Each cylinder has an associated pressure sensor to provide a signal indicative of pressure in the cylinder. The method includes identifying whether there is a non-fueling interval associated with any of the cylinder on the engine. The method includes determining at least one of parameters such as an indicated mean effective pressure, a peak cylinder pressure, a total heat released, or a total duration of heat released over a combustion cycle for the cylinder. The method includes comparing the at least one of the parameters with predefined threshold value, determining whether any of the parameters exceeds the predefined threshold value, and generating a signal indicating the impending cylinder failure if at least one of the parameters exceeds the corresponding predefined threshold value.

An engine unit includes an internal combustion engine and a misfire detection device. The misfire detection device includes a rough road traveling determination unit that: (a) determines a rough road traveling state based on a distribution state of a crankshaft rotation speed fluctuation physical quantity acquired by a crankshaft rotation speed fluctuation physical quantity acquisition unit, or (b) includes a vehicle traveling state detection unit for detecting a physical quantity in relation to a vehicle traveling state except the crankshaft rotation speed fluctuation physical quantity, and determines a rough road traveling state based on a detection result obtained by the vehicle traveling state detection unit; and suspends a determination of a misfire in the internal combustion engine based on a determination result obtained by the rough road traveling determination unit.

A device for monitoring the function of an engine is powered by heat from the engine or other sources other than a conventional, external direct electrical power supply, which may create sparks and/or be unavailable. The device monitors one or more of heat, vibration, or other parameters and can detect certain problems with engine function. The device is particularly suited for remote engine monitoring, and can store and/or display data concerning monitored engine characteristics, and/or directly or indirectly send such data to a location removed from the engine.

An engine trigger wheel is disclosed having a central annular portion and a cylindrical rim portion defining a number of trigger teeth, wherein the central annular and cylindrical rim portions are pressed from a single piece of metal. A number of balance apertures are formed in the central annular portion to move a center of mass of the trigger wheel away from an axis of rotation. The engine trigger wheel when fastened to one end of a crankshaft of an engine provides both an indication of the angular position of the crankshaft and a counterweight function.

A pressure detecting device that detects the combustion pressure in an internal combustion engine includes: a piezoelectric element that outputs a charge signal corresponding to the pressure in a combustion chamber; and a mounting board on which are mounted an integrating circuit that integrates the charge signal outputted by the piezoelectric element and an amplifier circuit that amplifies a voltage signal obtained by integration. On the mounting board are provided: a power receiving terminal that receives a power-supply voltage from a controller; an output terminal that outputs an output signal after amplification to the controller; and a grounding terminal for making the ground of the controller and the mounting board common. Furthermore, in the mounting board, the grounding terminal and grounding ends of the integrating circuit and the amplifier circuit are connected by way of grounding ferrite beads.

A plasma header gasket for use with an internal combustion engine includes electrodes disposed around the perimeter of apertures in the gasket corresponding to piston cylinders in the engine. The electrodes produce a plasma spark in time with the engine to increase the efficiency of combustion. The plasma spark produces an ignition discharge compatible with various types of engines and types of fuels.