Abstract: A catalyst heating control apparatus includes a catalytic converter arranged in an exhaust passage of an internal combustion engine, a heating part for heating a catalyst of the catalytic converter after the engine has started operating so as to promote a catalytic conversion of exhaust gas from the engine, a detecting part for sensing a temperature of engine coolant of the engine and a calculating part for determining a releasing condition based on an engine temperature sensed by the detecting part at the start of the engine operation. The heating of the catalyst of the catalytic converter is stopped when the releasing condition is satisfied. A stopping part stops the heating part from heating the catalyst of the catalytic converter when an operating condition of the engine satisfies the releasing condition.

Abstract: A device for determining a malfunction of an engine cylinder of an internal combustion engine, comprising a first detection unit for detecting a first engine speed at a predetermined first crank angle, and a detecting second engine speed at a predetermined second crank angle, during a power stroke of two engine cylinders under a continuous combustion cycle, a difference calculating unit for calculating a difference between the first and second engine speeds, a misfire determining unit for determining that a misfire has occurred in a corresponding engine cylinder when the difference is outside a predetermined limit, a malfunction determining unit for determining that a malfunction has occurred in the corresponding engine cylinders when a frequency at which the misfire determining unit determines that a misfire has occurred is larger than a predetermined frequency, a second detection unit for detecting a current engine load, and a first changing unit for changing at least one of the predetermined limit and the

Abstract: An intake air control device including swirl control means for controlling the intensity of a swirl in the combustion chamber. If combustion becomes worse during driving conditions under which a strong swirl should be created, an order means issues an order to actuate the swirl control means so as to weaken the intensity of the strong swirl. Next, a determination means determines whether combustion after the order is worse than combustion before the order, and when the result is negative, it is determined that a swirl control means problem has occurred.

Abstract: An air-fuel ratio control device comprising an O.sub.2 sensor arranged in an exhaust passage, an air-fuel ratio feedback correction amount calculating unit for calculating an air-fuel ratio feedback correction amount in accordance with an output of the O.sub.

Abstract: An evaporative fuel apparatus includes a first purge passage which connects a canister and an intake passage of an internal combustion engine and through which fuel vapor, stored in the canister, is purged into the intake passage, a control part provided in the first purge passage for controlling a flow of fuel vapor being fed from the canister to the intake passage, a detecting part for detecting a malfunction occurring in the control valve, a second purge passage which connects the canister and the intake passage and through which fuel vapor, stored in the canister, is purged into the intake passage, and a passage switching part for carrying out a passage switching to the second purge passage if a malfunction is detected by the detecting part, allowing the fuel vapor from the canister to be fed into the intake passage through the second purge passage.

Abstract: A diagnosis device for an exhaust gas recycling device diagnoses whether or not an exhaust gas recycling device is operating normally; the temperature of an exhaust gas recycling passage is detected by a temperature detection means, a decision is made by an exhaust gas recycling operating region detection means whether or not the operating region is such as to carry out exhaust gas recycling, when a decision is made that the operating region is such as to carry out exhaust gas recycling a counter is incremented and when otherwise is decremented, and a decision that the exhaust gas recycling is not being carried out normally, that is that the exhaust gas recycling device has failed, is made when the count value of this counter is at least a certain value and the temperature of the exhaust gas recycling passage is not more than a certain value.

Abstract: A diagnostic system of an air-fuel ratio control device including an O.sub.2 sensor and an air bleed control valve actuated in response to a signal output by the O.sub.2 sensor. When the electric control current fed into the air bleed control valve reaches an upper limit or lower limit and remains at the upper limit or lower limit for a fixed time, the diagnostic system determines that the air-fuel ratio control device has malfunctioned. When the temperature of the engine cooling water is high, a diagnosis is prohibited, to prevent an incorrect diagnosis.

Abstract: There is an indicating device constituted so as to be apt to indicate the data such as the magnification ratio of an objective lens, the value of NA, the data or the like in the visual field of a microscope and at the same time to record these data in photograph. This indicating device is provided with a display means (17) able to indicate various sorts of data informations through the data processor (16) and polarizing prisms (10, 11) arranged between the objective lens (9), display means (17), photographing lens (14) and eyepiece (13) to divide the light bundle from the objective lens (9) and the light bundle from the data display means (17) respectively and to make them advance to the eyepiece (13) and photographing lens (14), and the data informations displayed on the display means (17) are imaged on the image forming face (12) inside the eyepiece (13) and on the dry-plate (15).