The throttle switch is part of what tells the ECU to cutoff fuel to the
engine during coasting. When you are driving and you let off the gas
pedal the injectors get turned off since no power is needed. When you
put your foot back on the gas the switch opens and tells the ECU to turn
the injectors back on. If the switch sticks closed there will be
hesitation. If the switch is out of adjustment it can cause similar issues.

The ECU looks at engine rpm as well as the switch to determine whether
or not to cutoff the injection and when to turn it back on.

Mark

Martin Jagersand wrote:
> Thanks for the tip. Indeed it is an US spec FI engine.
> I'll try to unplug the throttle switch and see what happens.
> What does the switch control anyway?
>
>