A method and apparatus are disclosed for detecting a clogging of a fuel injector of an internal combustion engine. Each fuel injector of the plurality of fuel injectors may be tested for a clogging. A test injector is switch off. A requested value of a fuel quantity to be injected by the other fuel injectors of the plurality of fuel injectors is adjusted to operate the internal combustion engine in an idle mode. A difference is calculated between the requested value of the fuel quantity and a reference value of the fuel quantity to be injected by all the fuel injectors of the plurality of fuel injectors to operate the internal combustion engine in idle mode. The calculated difference for each test injector is used to identify if the test injector is clogged.

A throttle body fuel injection system and method that is arranged to easily replace four-barrel carburetors includes a throttle body assembly with four main bores, each with a throttle plate and an associated fuel injector. Each injector feeds fuel into a circular fuel distribution ring via a fuel injection conduit, which introduces pressurized fuel into the air stream. The fuel distribution rings and bores have profiles that avoid constrictions for to prevent low pressure zones according to the Venturi effect. Fuel is injected through downward-facing outlets at or near the bottom end of the rings. The fuel injection rings are two-piece, each formed of an insert pressed into an outer housing. The insert includes axial grooves intervaled about its exterior circumference of insert that are joined by a circumferential groove formed about the insert. The grooves are in fluid communication with a conduit that supplies fuel from a fuel injector.

A method for controlling engine revolution per minute (RPM) includes: a frequency deriving process for deriving a frequency from change in engine RPM detected by a detector by a controller during driving of the engine; a frequency conversion process for converting a derivation frequency derived in the frequency deriving process into a conversion frequency via a predetermined conversion process by the controller; a frequency comparison process for comparing an amplitude of the conversion frequency at which engine RPM is to be changed among conversion frequencies converted in the frequency conversion process with an amplitude of a reference frequency pre-inputted to the controller; and a fuel injection amount adjusting process for deriving a correction value based on a result derived in the frequency comparison process, for applying the derived correction value, and for controlling an injector by the controller to adjust a fuel injection amount.

A method and apparatus are disclosed for detecting a clogging of a fuel injector of an internal combustion engine. Each fuel injector of the plurality of fuel injectors may be tested for a clogging. A test injector is switch off. A requested value of a fuel quantity to be injected by the other fuel injectors of the plurality of fuel injectors is adjusted to operate the internal combustion engine in an idle mode. A difference is calculated between the requested value of the fuel quantity and a reference value of the fuel quantity to be injected by all the fuel injectors of the plurality of fuel injectors to operate the internal combustion engine in idle mode. The calculated difference for each test injector is used to identify if the test injector is clogged.

A method of operating an internal combustion engine, and more particularly a fuel injector is disclosed. The fuel injector is commanded to inject a fuel requested quantity. The fuel requested quantity is adjusted by closed-loop for controlling an engine speed to match a target value thereof. A value of a first parameter indicative of an amount of electrical energy supplied to an electric battery by an electric generator coupled to the internal combustion engine is measured. A value of a voltage generated by the electric battery and a value of the engine speed are measured. A reference value of the fuel requested quantity is calculated on the basis of the voltage value, the engine speed value and the value of the first parameter. A difference between the value of the adjusted fuel requested quantity and the reference value is calculated and used to control the internal combustion engine.

A method for operating an internal combustion engine in an idle mode, in which an ignition angle and/or an air quantity of the internal combustion engine is influenced and/or is modified as a function of an idle rotation speed of the internal combustion engine. The ignition angle and/or the air quantity and/or a fuel quantity for at least one combustion chamber of the internal combustion engine is modified as a function of at least one variable characterizing a combustion event in the combustion chamber.

According to the present disclosure, there is provided a method for controlling an RPM of an engine of construction machinery, including and converting and setting the received load factor to a load variation rate; receiving a current load factor of the engine and converting the received current load factor of the engine to a load variation rate; controlling driving of the engine with a corrected RPM, which is obtained by decreasing the RPM of the engine by a predetermined rate from a preset RPM when the current load factor of the engine and the load variation rate according to the current load factor are equal to or smaller than a predetermined rate of the predetermined load factor of the engine and a predetermined rate of the load variation rate for a first time, respectively; and controlling continuously decreasing the corrected RPM to a predetermined rate or smaller, when the current load factor of the engine and the load variation rate according to the current load factor are equal to or smaller than the predetermined rate of the predetermined load factor of the engine and the predetermined rate of the load variation rate for a second time, respectively.

A single input engine controller and system are provided for translating a single input indicative of the amount of fuel to be supplied to an engine from a fuel control interface into separate signals for controlling the amount of fuel supplied to the engine and the RPM of a propeller powered by that engine. The single input controller translating the single input into the separate signal for the RPM of the propeller according to a fuel efficiency relationship between the fuel amount and the propeller RPM.

A method and apparatus controlling the fuel-to-air ratio of a fuel and air mixture supplied to an operating engine includes the steps of determining a first engine speed before enleanment of the mixture, determining a second engine speed near or at the end of a period of enleanment of the mixture, and after ending the enleanment, determining whether the engine speed recovers within a predetermined range of the first engine speed and if so determining a delta speed difference between the first and second speeds and using this delta speed difference as a factor in determining a change in the fuel-to-air ratio of the fuel mixture supplied to the engine.

The present disclosure relates to a system for controlling vibration of an engine including an engine inertia portion which rotates together with the engine and a sub-inertia portion which influences a rotation speed of the engine and is separately provided, and a damper which is disposed between the engine inertia portion and the sub-inertia portion for reducing a vibration. The present disclosure includes: determining whether a vehicle is in an idle state; sensing rotation speeds of the engine inertia portion and the sub-inertia portion, respectively; calculating an average value of the rotation speeds of the engine inertia portion and the sub-inertia portion; calculating an error value from the average value; and PI controlling by receiving the error value.