vaccuum, weird problem?

[mailmanmike]

Hi all, I searched this forum for an answer, but I'm not sure I found it, so:
83 300d turbo, 230,000 miles.
Suddenly one day, engine wouldn't shut off without depressing locks on door.
Then, suddenly, a month later,engine won't shut off AND no power brakes.
Car sits overnight, starts, power brakes come back.
After car gets warmed up and re-started, brakes and shutoff go out again.
Am I more than likely looking at a vaccuum pump?
If so, is it common for them to intermittently go bad?
Thanks in advance.