PontiacBonnevilleClub.com

A couple years ago I lost the ability to control the air conditioner vents on my 98 SSEi. It only blew out the defroster and floor vents. I found a post that diagnosed the problem and fixed it. - http://www.pontiacbonnevilleclub.com/fo ... =19&t=2884 - Which was so simple and effective I felt dumb. It worked great until this spring. Under acceleration, it would divert the air from where ever to the floor/defrost. I figured i had a vacuum leak some where and just lived with it as it seemed to be localized to the air-co system. But it got progressively worse as the summer went on and now that is it 105 it is not working at all. Now the air is freezing cold and blow fast(high volume) the car EVENTUALLY cools off and I get a lovely frost patch on my windshield! It is only the air diversion part of the system. I replaceed a couple suspicious vacuum lines under the hood. As I was looking under the dash, I noticed the recirculate door does work. I assume vacuum controlled as well.

Now for the questions:
1 - Is there a good starting place to start inspecting the vacuum system, a place that is more prone to problems?

2 - Is there an easier way to go about tracing the vacuum lines that tearing out things like the dash? I am kind of wishing I had bench seats.

3 - I am just assuming the problem is with the vacuum system. The way the problem started (it only happened under load) and got worse. That says vacuum leak to me. But I may be wrong, I checked the applicable fuses, did not check relays. Does this sound like anything else could be wrong?

I miss my baby and a dark car in an Oklahoma summer is a pain with a good air-co. So no driving for me!!

Squirt some intake cleaner at some of the joints/connections of the vacuum lines while the engine is running. If the RPM rises, it indicates a vacuum leak.

The post you linked to also talks about the connection at the reservoir as well as the nipple collapse problem at the programmer, you might want to look at those as well.

Ok, I will have some time this evening to try that. I visually checked the reservoir and and connection. I did check the vacuum system under the hood and I am 95 percent sure it is not there. But again, I will try the intake cleaner.

Finally had enough time off to poke around. Thankfully it was not so hot that I wanted to kill myself. So I was standing if front of the car and just happened to look up and said, that looks like a vacuum line. Whoo hoo, I missed one and it was completely rotted apart. AND it terminated right as it went into the firewall. No tearing things apart for me! It was the little exposed loop from the vacuum reservoir to the check valve near the firewall. I feel dumb for missing it all this time, IT WAS RIGHT ON TOP!! I kind of forgot what cool air felt like. I'm sure my wife's mom is happy to know I fixed the problem a few days after I had to pick her up from the airport on a 104 degree day!