Air Charge Temperature Sensors
The air charge temperature sensor is a tiny computer in the engine that collects information about the temperature and pressure of the air entering the combustion chamber. It works in tandem with the manifold absolute pressure sensor and sends this information to the ECU, or the engine control unit. This information is used in calculating the density of the air and then in calculating the amount of fuel to add to the mix for combustion to happen optimally. At wide open throttle, the air charge temperature sensor’s information is critical since the oxygen sensor is not in use at that time. At idle this information is also important in determining the idle speed. It is used on turbo engines mostly in the 1980s. When it is malfunctioning the care may be difficult to start or stall when the car comes to a stop. Replacement may require the removal of other parts like the air duct assembly.