Hi all.. I did a search and looked in the Techinfo but came up with nothing on the topic, so here goes.

My car is a 1994 SSE with the electronic Climate Control. Everything works fine EXCEPT this... When I have the air blowing out the dash vents ( mid level) and am driving under acceleration, the air flow drops considerably and blows out the floor ducts. When I coast or idle, the air flow returns to the vents in the dash.

I assume this is due to a vacume problem, but it is just a guess as I really do not know what to check. Any of you have this happen and or know what to look for?

Thanks in advance.

I did find one topic that talked about your problem but there was no definative answer.
http://www.bonnevilleclub.com/forum/viewtopic.php?t=357

Usually when there is a loss of vacuum to the climate control system, the air flow defaults to the defroster not the vents. That makes it a bit of a head scratcher but the first thing to check is the vacuum reservoir and the line to it. I wouldn't expect to see it totally disconnected but check for dry and brittle rubber connections that would cause a small leak.

Thanks for the info, If anyone else has any it would be great to know about.

I'll bet any amount of money it'* the vacuum hose that runs to the firewall.

One thing I want to be sure and clarify though is that the vents, defrost, and floor vents all operate accordingly. So I am obviously getting some vacuum in order for the change of airflow correct? Its just the change of airflow under acceleration that gets me confused.

My 93 diagram is showing that the floor vents are partially open by design so you will always have some air to the floor. I can now stop scratching my head trying to figure that out. So this means that you are simply loosing vacuum pressure, as in a leak, rather than a completely dicsonnected vacuum line.

Off to use my new vacuum gauge to find out where my system is failing. Will double check my open by design on FSM in a little

Edited because it took me so long to fix it. Hose from intake unplugged at firewall. Camera giving hard time. Off to get some fresh vacuum line. Good thread, how is it everyone starts a thread with my problems right before I have them?

The vacuum line problem was right on. Although I have not touched it yet,, ( I plan to tackle it tomorrow if work is slow enough) I looked at it Today and sure enough the vacuum line kinda crumbled as I touched it. I noticed it comes from the firewall and goes into a plastic T that also is connected to my air compressor for the air leveling system and I supose also works the trunk air compressor system. Anyway, the plastic T was also brittle enough it broke too. So I plan to replace my vacuum lines within the next day or two and I will sure let you know how it turns out. I think it will fix my problem.

Thanks for all the help and possible areas to look for. And once again, I will let you know if it fixes the problem.

WAIT!

Ummmm....the ELC suspension and compressor don't have ANYTHING to do with vacuum whatsoever. Re-trace that line. I bet you'll find it goes to your charcoal canister

I've gotten the vacuum line, but do I really need to replace a crumbling cracked falls off by itself line if it'* holding at the moment....lol

When you go to buy vacuum line, bring a piece of the old one with you. There are many sized and when they ask and you say "small" they'll ask you to identify the size in question. Easy to do if you have a piece of it ready. Also, pick up more than you need....it never hurts to have a little sitting on the shelf. It cost me about 50 cents for 4 feet of it. (The whole time Randy'* looking at me with a "whatcha doing with 4 feet" look.)