[metroschultz]

That is the start capacitor.
If the pump starts quickly and runs smoothly, then you have a mechanical issue.
Did you purchase new or used?
Did it work yesterday and quit today?
or Has it been ailing since you owned it?
You may want to disassemble the unit and check clearances on all the moving parts.
Yes you are going to need the specific oil that manufacturer calls for. (Google?) Some use mineral oil, some use ester and some use pag (?others?). All available in different viscosities.
If you have a manual that will help. If not you need to do some research and get info on your unit.
We will help as much as possible.
There are hundreds of different types of vacuum pumps on the market so getting info is crucial.
TTFN