MAF

A mass airflow sensor is used to determine the mass of air entering an electronically fuel-injected engine. The air mass information is necessary for the engine control unit (ECU) to calculate and deliver the correct amount of fuel to the engine. Air changes its density as it expands and contracts with temperature and pressure. In automotive applications, air density varies with the ambient temperature and altitude, and this is an ideal application for a mass sensor. There are two different styles of MAF sensors that are used in the F body from 94-02. The LT1 motors (94-97) employs a hot wire sensor that heats up a wire suspended in the air stream. As the wire heats up the electrical resistance increases, as more air flows over the wire it decreases the temperature of the wire and electrical resistance decreases. In response to this cooling more current is supplied by the ECU to the wire suspended in the air stream to maintain the temp of the hot wire. The ECU calculates how much air is flowing through the motor based on how much current has to be supplied to the hot wire to keep it at the specified temp. LSx powered f bodies (98-02) use a "coldwire" MAF system where the inductance of a tiny sensor changes with the air mass flow over that sensor. The sensor is part of an oscillator circuit whose oscillation frequency changes with sensor inductance; the frequency is related to the amount of air passing over the unit. This oscillating electrical signal is then fed to the car's ECU.