MAP/AMF???

[NoHachi]

AFM stands for air flow meter and thats exactly what it does, measure the amount of air going into the engine allowing the ecu to add correct amounts of fuel. 2 Styles are known, newer models use a couple (or mesh) of heated wires and calculate the amount of air by measuring the temperature=resistance drop over the wires. The AE86 uses a kind of flapper gate, where the air pushes a springloaded flapper out of the way before entering the engine.deflection angle and rate of the flapper give hints about the amount of air going in. Either way, there are some things placed in the airflow to measure it, this causes minor resistance.

MAP=Manifold Air Pressure based. Here you measure the pressure drop in the manifold resulting from the engine sucking in air. The higher the vacuum, the higher the flow, the more fuel needs to be injected.