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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,273
With all the confusion and multiple names for the deceleration valve, AAV, and AAR I just call them golden saucer valves now.
The early 930's had 2 golden saucer valves, one has a small vacuum line that opens it during times of high intake manifold vacuum and that one is the deceleration valve or vacuum limiter valve.

The other saucer valve doesn't have a small vacuum line that operates it and only the 2 larger hoses that bypass the throttle body. That one is called the AAV most of the time and the late eightee's 930's do not have one of those, thankfully.

The last throttle body bypass valve is the AAR that is cast aluminum and looks nothing like a golden saucer valve. This one bypasses air around the TB when the engine is cold so the idle is raised. I call that one the aux. airslide valve to try and make it less confusing.

Your engine is running a little rich when idle oscillates while warmed up. There are alot of things that could cause that and the simplist thing may be the air sensor plate pivot bearing is just a little stiff or gummed up and not raising back up to where it should at idle.
Could be a vacuum leak(s) and could be your control pressure regulator being inconsistant too.

Next time you have the rear tin off you might want to take the time to strip off all the rust with phosphoric acid, sand or bead blasting, or wire brushes on a die grinder... whatever works for you. Then paint it with 1500 degree header paint or barbecue paint.
It'll stink when the paint burns off right above the turbine housing at first but will make the tin last longer and look alot better down the road.
They are getting very expensive for a piece of stamped out and spot welded sheet metal and not easy to find when they rust away.
Old 10-20-2009, 11:15 AM
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