Where are you located, and is this a new symptom or a new car?

Can you move the shutoff lever shaft in/out (axial play) of the pump? If so, it is possible that someone has replaced the seal and did not install the snap-ring and spacer before installing the shutoff lever.

If all is well externally, remove the shutoff actuator on top (need to remove the intake plenum and ALDA first), look down to see if the arm that is inside of the pump has been bent and is binding with other linkage. Does it still bind with the (vacuum) shutoff actuator removed? If the shutoff lever seal was serviced incorrectly, it is possible that someone has bent it internally (removing threaded bushing instead of snap-ring).

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Gone to the dark side

- Jeff