Pontiac Repair: car wont enage, vacuum modulator, vacuum regulator

Question

the hose I have a 94 bonneville se. Anytime the car sits for an extended period of time, I have to pull this hose of this piece,the vacuum regulator or accumulator, I'm not sure I was given two names for it to engage in drive or reverse. If I don't do this the car will not move into gear. After I let the hose run for about a min and replug it, the car works fine. This only happens when the car sits for awhile. Whats the deal here?

Answer
Hi Ted that is a vacuum modulator. The diaphram may be leaking and filling the hose up with oil and that is why you are having that issue. Not very common but from the picture it looks pretty rotted out and it has lived a hard life. But that is what it's called.
That controls transmission up shifts. good luck :)