You have a vacuum problem. Unfortunately, I can't help because
1) I don't know what I'm doing
2) My model is different than yours.

However, I am going to fix mine tonight while I have a Mity Vac. I rented it for free from Auto Zone. They have a free rental program on a lot of tools.

My vac pump is under the rear seat, yours is different.

Good luck with it.

Jeff 1991 300d