Hi all,

My Bonneville idles rough. I don't get any computer codes. I replaced the plugs and wires. I did a compression check and that seems to be fine. So, my thinking is that it might be a vacuum problem. I did some poking around under the hood and found a few things.

First, on the back side (towards the passenger compartment) of the vacuum source on top of the */C there are 3 vacuum lines. One of them is a big line that keeps vacuum in the reservoir, then there is another one in the middle. Finally, they third one (towards the passerger side) just has a short hose with a bolt in to plug it. Is that right? If not, where is that line supposed to go?

Second, to left of the vacuum canister (as you're looking at the car from the front) there is a black box with 2 vacuum lines coming out of the bottom. On my car the top one has a line connect to it, but the botton line has nothing. Should there be something connected there? If so, where does it go?

Finally, on the side of the cruise control module there is a tube that sticks out that looks like it should have a vacuum line attached to it, but there is not. Any ideas on this one? The cuise control does not work.

Thank you in advance for any help here. I hope my descriptions are accurate enough. I have pictures, but it doesn't seem I can attach them to this post.

Thanks!

If your describing the hose i am thinking of (with the bolt in it) it should goto the fuel regulator. That would be a huge reason for running rough...

On the other side of the vaccum "distribution block" (towards the front of the car) there is two hoses coming out (on my 94 anyway) they have two 180* elbows and then small plactic vaccum lines.. one will run to a canister and the other will goto the cruise control.

I hope that helps...

PS... there should be a sticker on top of your radiator that describes where all of the vaccum lines should go...

He'* right, I believe. The bottom vacuum prong on the tank should go to the cruise. The other controls where the climate control blows.

I would guess that if your car has no vacuum supply to the regulator, it would dump in way too much fuel at idle.