Abstract: According to one embodiment of the invention, an internal combustion engine includes a first exhaust port in a cylinder head of the internal combustion engine, a first one way valve coupled to a secondary air system, the first one way valve configured to restrict fluid communication from the first exhaust port to the secondary air system. The engine also includes a second exhaust port in the cylinder head and a second one way valve coupled to the secondary air system, the second one way valve configured to restrict fluid communication from the second exhaust port to the secondary air system, wherein the first and second exhaust ports are in fluid communication with a turbocharger.

Abstract: A system according to the principles of the present disclosure includes a desired injection duration module, a fuel control module, and a throttle control module. The desired injection duration module determines a desired injection duration. The fuel control module compares the desired injection duration to an injection duration limit and controls a fuel injector of an engine based on the injection duration limit when the desired injection duration is greater than the injection duration limit. The throttle control module controls a throttle of the engine based on the injection duration limit when the desired injection duration is greater than the injection duration limit.

Abstract: According to one embodiment of the invention, an internal combustion engine includes a first exhaust port in a cylinder head of the internal combustion engine, a first one way valve coupled to a secondary air system, the first one way valve configured to restrict fluid communication from the first exhaust port to the secondary air system. The engine also includes a second exhaust port in the cylinder head and a second one way valve coupled to the secondary air system, the second one way valve configured to restrict fluid communication from the second exhaust port to the secondary air system, wherein the first and second exhaust ports are in fluid communication with a turbocharger.

Abstract: A vehicle engine utilizes adaptive knock retard in which non-volatile memory cells store slowly changed values based on sensed knock to retard ignition timing. Upon engine start, the values in one or more of the memory cells may be reduced in a proportional manner to provide a more advanced engine ignition timing more appropriate to engine warmup. The proportional reduction is based on the sensed engine coolant temperature at the initiation of engine operation, either by itself or through the difference between it and the stored engine coolant temperature from just before the cessation of the last period of engine operation.

Abstract: An ignition timing system activates combustion ignition apparatus in a combustion chamber at times established at least partly in response to a knock retard value. The knock retard value is normally modified in response to a knock signal generated by a knock sensor during a knock window corresponding to a predetermined crankshaft rotational angle in which knock is to be sensed. However, if the knock signal is determined to be present at the beginning of an occurrence of the knock window, modification of the knock retard value in response to the knock signal is prevented during that occurrence of the knock window, since a knock signal already present at the beginning of the knock window is assumed to be noise.