Greg --

The air mass meter measures the air "inhaled" by your engine. The amount of air going into your engine depends on engine speed and throttle position (how much you're pushing the pedal). The fuel injection controller pulses the injectors to send fuel to the cylinders in an amount proportional to the air induction, load, and temperature.

When you unplug the AMM, the controller reverts to a fixed "recipe" of fuel delivery. It no longer depends upon an airflow measurement, but uses an internal (pre-programmed) value for driving the fuel injectors. This is called the "limp home" mode, and allows you to drive slowly, off the highway, home, or to the shop if/when the AMM fails.

With the AMM unplugged, as you push more and more on the accelerator you're sending increasing amounts of air into the engine -- but the controller no longer knows this, and continues to send the same fuel flow. So you're running your engine more and more lean.

Conventional wisdom says this is not good -- running an engine overly lean can burn valves, you have no real power, and you will be unsafe on the roads.

I wouldn't do this.

To answer another of your questions -- the AMM is an instrument called a "hot wire anemometer". Basically, it's a wind speed meter.

The AMM has a heated platinum wire. As air flows past this heated wire, it removes heat from the wire (cools it), and the wire's resistance changes. More air, more cooling, and more resistance change. The built in electronics measures this resistance change and translates it to airflow. Based on this, the electronics tailors the fuel flow through the injectors to maintain proper mixture.

BTW -- be sure you ONLY unplug/replug the AMM with the ignition off. Otherwise you risk damaging an expensive component (that might not be defective).