Abstract: A system for a vehicle includes a humidity determination module, a specific humidity module, and a parameter control module. The humidity determination module determines a first specific humidity of air based on a relative humidity of the air measured by a humidity sensor in an intake system of the vehicle. The specific humidity module sets a second specific humidity of the air equal to one of the first specific humidity and a predetermined specific humidity of the air in response to a comparison of a mass air flowrate (MAF) into an engine and a predetermined flowrate. The parameter control module controls at least one operating parameter of an engine based on the second specific humidity.

Abstract: A system for a vehicle includes a humidity determination module, a specific humidity module, and a parameter control module. The humidity determination module determines a first specific humidity of air based on a relative humidity of the air measured by a humidity sensor in an intake system of the vehicle. The specific humidity module sets a second specific humidity of the air equal to one of the first specific humidity and a predetermined specific humidity of the air in response to a comparison of a mass air flowrate (MAF) into an engine and a predetermined flowrate. The parameter control module controls at least one operating parameter of an engine based on the second specific humidity.

Abstract: A fuel control system for an internal combustion engine includes a fuel starvation detection module and a fuel pump protection module. The fuel starvation detection module detects when a fuel pump is delivering less than a predetermined amount of fuel based on a fuel level in a fuel tank, a fuel pressure in the fuel pump, and an air/fuel (A/F) ratio of the engine. The fuel pump protection module decreases an amount of fuel supplied to the engine during a period after detecting that the fuel pump is delivering less than the predetermined amount of fuel.

Abstract: A fuel pressure control system for a vehicle comprises a pressure regulator module and a pressure increasing module. The pressure regulator module regulates a fuel pressure supplied to an engine to a first predetermined pressure during an engine running period. The pressure increasing module selectively increases the fuel pressure to a second predetermined pressure during the engine running period when a counter value is one of greater than and less than a predetermined final value. The second predetermined pressure is greater than the first predetermined pressure, and the counter value is set to the predetermined final value after the engine is started for a first time after being assembled.

Abstract: A fuel control system for an internal combustion engine includes a fuel starvation detection module and a fuel pump protection module. The fuel starvation detection module detects when a fuel pump is delivering less than a predetermined amount of fuel based on a fuel level in a fuel tank, a fuel pressure in the fuel pump, and an air/fuel (A/F) ratio of the engine. The fuel pump protection module decreases an amount of fuel supplied to the engine during a period after detecting that the fuel pump is delivering less than the predetermined amount of fuel.

Abstract: A fuel pressure control system for a vehicle comprises a pressure regulator module and a pressure increasing module. The pressure regulator module regulates a fuel pressure supplied to an engine to a first predetermined pressure during an engine running period. The pressure increasing module selectively increases the fuel pressure to a second predetermined pressure during the engine running period when a counter value is one of greater than and less than a predetermined final value. The second predetermined pressure is greater than the first predetermined pressure, and the counter value is set to the predetermined final value after the engine is started for a first time after being assembled.