Be careful of confusion due to labelling. The throttle plate is likely not visible. It is hidden well below the airflow meter plate. The throttle plate is connected to the throttle linkage, and can be expected to open when the accelerator is pressed. It is bypassed by the idle control valve, whose opening is controlled by the engine management computer.

The airflow meter plate is not operated by any linkage or computer. It is designed to open as a function of airflow demand - as airflow increased, it is pulled open by the differential air pressure only. It is linked to the fuel distributor, and determines mechanically the fuel mixture.

Now reanalyse what is happening.

Steve

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'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7