Abstract: The variable valve timing control device according to the present invention controls the valve timing of the intake valves of the engine based on the optimum valve timing at the full load operation of the engine. Namely, the variable valve timing control device of the present invention determines the valve timing in accordance with the combination of the present engine load and the present engine speed in such a manner that the deviation of the valve timing from the optimum valve timing when the engine is operated in full load at the present speed does not exceed a predetermined maximum allowable value. Since the valve timing of the engine is always set within a range determined by the maximum allowable deviation from the optimum valve timing for the full load operation, when the engine is accelerated to the full load condition the amount of the change, i.e., the amount of the operation of the variable valve timing control device is kept always within the range determined by the maximum allowable deviation.

Abstract: A malfunction detection apparatus for detecting a malfunction in an evaporated fuel purge system in which fuel vapor from a fuel tank is adsorbed in an adsorbent in a canister and the adsorbed fuel vapor in the adsorbent is purged into an intake passage of an engine. The apparatus includes a detection part for detecting a concentration of fuel in the fuel vapor purged into the intake passage so that a change in the detected fuel concentration from a time when a purge cutting is performed to a time when a purging is performed after the purge cutting has been performed is detected, and a discrimination part for determining whether there is a malfunction in the system on the basis of the change in the detected fuel concentration by the detection part.

Abstract: A malfunction detection apparatus for detecting a malfunction in an evaporated fuel purge system in which fuel vapor from a fuel tank is adsorbed in an adsorbent in a canister and the adsorbed fuel vapor in the adsorbent is purged into an intake passage of an engine. The apparatus includes a detection part for detecting a concentration of fuel in the fuel vapor purged into the intake passage so that a change in the detected fuel concentration from a time when a purge cutting is performed to a time when a purging is performed after the purge cutting has been performed is detected, and a discrimination part for determining whether there is a malfunction in the system on the basis of the change in the detected fuel concentration by the detection part.