A method for operating an internal combustion engine with multiple cylinders. Each cylinder of the internal combustion engine includes at least one fuel injector, and each fuel injector is activated for opening and closing via a solenoid valve of the respective fuel injector. Structure-borne sound waves emitted by the fuel injectors and/or accelerations caused by the fuel injectors are detected by measurement. The structure-borne sound waves detected by measurement and/or the accelerations detected by measurement are evaluated, and based on the evaluation, characteristics of the fuel injectors are automatically determined.

A fuel tank containing a fuel and oil mixture is managed to determine if the fuel and oil mixture contains the correct ratio for a motor. The fuel tank containing a fuel and oil mixture is monitored. A fuel to oil ratio is selected for the motor. A combined viscosity of the fuel and oil mixture is calculated with respect to the fuel to oil ratio, and the temperature of the fuel and oil mixture. The combined viscosity is used to determine a predetermined range of the combined viscosity. The viscosity of the fuel and oil mixture within the fuel tank is measured as a measured viscosity. If the measured viscosity of the fuel and oil mixture does not correspond with the predetermined range, then a user may be alerted that the measured viscosity does not correspond with the predetermined range.

A method for controlling a dual fuel engine system includes determining a friction power loss amount of an internal combustion engine of the dual fuel engine system, where the friction power loss amount is based on an engine speed of the internal combustion engine and a friction torque estimate. The method also includes determining an accessory power loss amount of a power of the internal combustion engine, where the accessory power loss amount is based on the engine speed and an accessory torque estimate. The method further includes estimating a net engine power amount based on the accessory power loss amount and a brake power amount of the internal combustion engine, estimating an indicated diesel power, and estimating, based on the estimated net engine power, a first indicated engine power and a first gas power.

A method of detecting uncontrolled combustion in an internal combustion engine includes sampling in-cylinder pressure sensor configured to measure pressure in a cylinder of the engine and generate a pressure signal, calculating a combustion intensity metric based on the pressure signal, determining a parameter describing how close the engine is to an uncontrolled combustion condition based on the combustion intensity metric, and controlling a substitution rate of a first fuel and a second fuel based on one or more of the parameter and the combustion intensity metric.

A fuel tank containing a fuel and oil mixture is managed to determine if the fuel and oil mixture contains the correct ratio for a motor. The fuel tank containing a fuel and oil mixture is monitored. A fuel to oil ratio is selected for the motor. A combined viscosity of the fuel and oil mixture is calculated with respect to the fuel to oil ratio, and the temperature of the fuel and oil mixture. The combined viscosity is used to determine a predetermined range of the combined viscosity. The viscosity of the fuel and oil mixture within the fuel tank is measured as a measured viscosity. If the measured viscosity of the fuel and oil mixture does not correspond with the predetermined range, then a user may be alerted that the measured viscosity does not correspond with the predetermined range.

A sensor failure diagnostic apparatus includes a first estimation unit to estimate a mixing ratio of each type of a molecular structure included in a fuel, based on combustion parameters when a combustion of an internal combustion engine is executed in different combustion conditions, among the combustion parameters sensed by a combustion sensor, a second estimation unit to estimate the mixing ratio, based on characteristic parameters sensed by a characteristic sensor, a combustion sensor diagnostic unit to determine whether a failure of the combustion sensor exists, based on a sensed value of the combustion sensor when the combustion is not executed, and a characteristic sensor diagnostic unit to determine whether a failure of the characteristic sensor exists, by comparing the mixing ratio estimated by the first estimation unit with the mixing ratio estimated by the second estimation unit when the combustion sensor diagnostic unit determines the combustion sensor is normal.

A system for remotely monitoring and controlling operation of a hydro-diesel engine, having: (a) a diesel engine assembly; (b) a hydro-diesel assembly connected to the diesel engine assembly; (c) a remote control system; and (d) a remote computer system in communication with the remote control system, wherein the remote computer system is configured to instruct the remote control system to turn off operation of either: (i) the hydro-diesel assembly while permitting the diesel engine assembly to continue operation while the hydro-diesel assembly is not operating, or (ii) both the hydro-diesel assembly and the diesel engine assembly.

A fuel tank containing a fuel and oil mixture is managed to determine if the fuel and oil mixture contains the correct ratio for a motor. The fuel tank containing a fuel and oil mixture is monitored. A fuel to oil ratio is selected for the motor. A combined viscosity of the fuel and oil mixture is calculated with respect to the fuel to oil ratio, and the temperature of the fuel and oil mixture. The combined viscosity is used to determine a predetermined range of the combined viscosity. The viscosity of the fuel and oil mixture within the fuel tank is measured as a measured viscosity. If the measured viscosity of the fuel and oil mixture does not correspond with the predetermined range, then a user may be alerted that the measured viscosity does not correspond with the predetermined range.

A device is provided, which makes it possible to perform a failure diagnostics for a filter more accurately even in the case of an internal combustion engine which is constructed to be capable of using both of gaseous fuel and liquid fuel. The device of the invention comprises judging means which judges any failure of the filter by comparing the added-up amount of the particulate matter contained in the exhaust gas as detected by a PM amount detecting sensor during a predetermined period and the added-up amount of the particulate matter contained in the exhaust gas as estimated by PM amount estimating means during the predetermined period, wherein the PM amount estimating means estimates the added-up amount of the particulate matter contained in the exhaust gas on the basis of the predetermined parameter and only a fuel injection amount of the liquid fuel out of a fuel injection amount of the gaseous fuel and the fuel injection amount of the liquid fuel.

A control system for a dual fuel engine having a liquid fuel supply and a gaseous fuel supply is disclosed. The control system may include at least one sensor operably coupled to a cylinder of the dual fuel engine and configured to monitor cylinder condition and transmit a cylinder condition signal. Additionally, a controller may be communicably coupled with the at least one sensor and the controller may be configured to receive the cylinder condition signal and determine whether the cylinder is operating in an abnormal operating condition. Whereas the controller determines the cylinder is operating in the abnormal operating condition, the controller sends a control signal for the liquid fuel supply to provide an amount of liquid fuel which is greater than an amount of liquid fuel supplied to the cylinder during a normal operating condition.