For other uses, see Warm air intake (disambiguation). A heated air inlet or warm air intake is a system commonly used on the original air cleaner assemblies of carburetted engines to increase the temperature of the air going into the engine for the purpose of increasing the consistency of mixing of the air and fuel in order to reduce engine emissions and fuel usage. Heated air intake systems operate on the principle of increasing the temperature of the air. The fuel will more effectively stay in suspension in the air rather than falling out of suspension and forming droplets on the floor of the manifold. Warm air from the outside of an exhaust manifold is drawn up into the air cleaner to increase the air temperature as quickly as possible after the engine starts. The air cleaner assembly incorporates a thermostatic vacuum switch that responds to the air temperature after the air filter element and actuates a vacuum motor that moves the control flap to allow the air to be drawn from a cooler location such as the top of the engine bay or outside the engine bay.

If the air becomes too cold, the thermostatic switch will automatically change back to drawing heated air from around the outside of the exhaust. The system was often used with computerised carburettors or throttle body injection systems but is typically not used with multi-point fuel injection, as the problem of fuel falling out of suspension does not occur when the fuel injectors are located close to the inlet valves.how do spider plants clean air There are exceptions to this however. rental of air purifierSome vehicles, such as the 1992 and 1993 Fox body Mustangs, do use such as a system even though they have multi-port fuel injection, presumably to help the air-fuel mixture burn at the proper rate in cold weather, as even though the fuel has finely atomized, it has not properly vaporized, and therefore flame propagation will be otherwise slower. air purifier motor

These vehicles have a MAF sensor, Air Temperature sensor, and when equipped with the 2.3L 4-cylinder, two spark-plugs per cylinder. This combination ensures the air is just warm enough to vaporise the droplets and does very noticeably improve performance and emissions at the same time in cold, northern winter weather. Heating of the intake air is specifically used for liquid fuels such as petrol that do not atomize easily under the temperature and pressure conditions present in the intake system of an engine prior to coming up to full operating temperature. Fuels such as liquefied petroleum gas and natural gas do not require this heating, as they are in gaseous form in the intake, mix more effectively with the air and cannot fall out of suspension. While heating the inlet air provides a benefit by improving homogeneity of the inlet air and fuel, it has the disadvantage of reducing air density, which reduces the volumetric efficiency of the engine. The installation of a heated air intake system is hence beneficial to engine emissions but decreases maximum available power.

Where heated air intake air cleaner assemblies are fitted to engines, it is a common perception that they reduce maximum engine power and it is consequently common for them to be removed and a more open air cleaner assembly fitted in their place. This has the benefit of a marginal increase in power with the disadvantage of significantly increased emissions and, in some jurisdictions, making the vehicle illegal. ^ "Automotive Mechanics: Service, Repair, Diagnostics"; James E Duffy, Martin T Stockel & Martin W Stockel; MARK’S CORNER – AUTO REPAIR HELP THERMOSTATIC AIR CLEANER (TAC) Troubleshooting a car’s emission system often involves inspection of the thermostatic air cleaner (TAC system). The TAC is used to provide warm air to the air cleaner during cold start up. This helps to improve cold engine performance and reduce automotive emissions by providing better fuel vaporization. The TAC system is primarily used on carbureted and throttle body injected vehicles.

The typical TAC system uses a vacuum motor to actuate an air flow door, located in the air cleaner inlet. The vacuum motor is operated by a signal from a thermostatic switch located in the air cleaner assembly. Warm air is supplied to the air cleaner via a hose that connects from a shroud mounted on the exhaust manifold, to a port on the underside of the air cleaner inlet. During cold engine operation, the actuator closes the air flow door and warm air is drawn into the engine from around the exhaust manifold (take special note of this during a diagnosis of the TAC system). As the engine warms up, the vacuum signal is removed from the actuator and the door slowly opens to allow cooler air to enter through the air cleaner inlet, while at the same time, blocking warm air from the exhaust manifold. Some TAC systems do not use a vacuum actuator to control the air inlet door. Instead, a sealed actuator containing wax is used. When the engine is cold, the wax solidifies and contracts, causing the door to close.

As the engine warms up, the wax liquefies and expands, placing pressure on a piston that is used to actuate the door. The TAC system functions well to aid in cold start up. However, if the air cleaner door were to stay in the closed position after the engine reaches operating temperature, lack of power and hard starting could result. Visual inspection of the TAC system can usually determine if this is the cause of these symptoms. If you are doing the auto repairs yourself or if you have hired your local auto repair mechanic to do it for you, the first step should be to visually inspect the TAC system. gave up on sports when the Browns left Cleveland and now spends his Sundays working under a shade tree in the back yard tuning his son’s soap box derby car.)The following terms and their definitions are related to both OBD1 and OBD2 systemsThe requested URL /EAC%205086%20EAC5086%20Jaguar%20Vacuum%20Thermal%20Valve.htm was not found on this server.Select a different machine