ok bill sorry about not being that descriptive. if i pull the vaccum line off the brake booster the idle does not change. if i pull the vaccum line off of the purge valve the idle gets higher.

OK. You pull the vacuum line off the brake booster and plug the line?
OR....You pull the vacuum line off the brake booster and let the vacuum line suck air?

Which did you do?

If you pull off the line and plug it and the idle does not change, that would imply no leaks in the booster.

And did you plug the line to the purge valve when you pulled it?

And did the idle improve, smooth out, when it got higher?

i pull the line off the brake booster and dont plug it and the idle does not change if i plug it it doesnt change either now i pull it off the purge and the idle goes up and i plug it and it goes back down

This does not sound right.

The brake booster line to the intake manifold is really big. If you pull it off and let it suck air, there should be a huge difference in the idle. And the idle should return to normal when you plug it.

Unless there is a check valve that I'm unaware of. I'll check this out on my car just to make sure and get back to you.

ok thanks

When I pulled the big vacuum line off of the brake booster on my '95 SLE and let the hose suck air, the engine almost died, it stumbled, then began to run a little more quickly and finally resumed a functional but kinda lopey idle. The PCM must be able to compensate very quickly for even huge vacuum leaks. When I reattached the hose to the booster, it regained the normal idle even faster.

This ability of the PCM to compensate for such a huge vacuum leak means that you need to be very quick in evaluating the change in idle quality when a hose is removed in order to determine if the vacuum system you are disconnecting has a leak or not.

One thing you might want to try is to find someone with an engine similar to yours and compare what happens between the two when you pull off a hose.

Are there any BC members near you who could help out this way?

i dont know anyone from around here thats a part of bonnevilleclub even though that would be great

Where are you located?

westchester county ny

btw there was a check valve where all the 2 hoses connect onto the brake booster i pulled it off of there and it did the same thing as when i pulled it off the purge so that rules that out.

i will have a 92 parts bonneville tomarow to take any parts off i want as long as i can leave it at my house for 2 weeks any ideas on what i should take off and what i shoud start taking off to see what my problem is.