Thread: Ignition Timing
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jwasbury jwasbury is offline
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Join Date: Jan 2008
Location: Weehawken, NJ
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Originally Posted by 930turbo View Post
Your '79 has two ports, one vacuum and the other boost. The port on top is influenced by vacuum, the port at the base/front is boost. This allows the vacuum to lean slightly under light load and enrich slightly under boost.

FWIW, I tested my Control pressure regulator (WUR), and found that it does not respond to vacuum, only to boost. This is on my '79 US model.
AFAIK, there is only one port that goes to the Manifold on my WUR (which is the correct p/n for a '79 US), the port on top is a vent which is plumbed to the airbox.
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Old 02-11-2009, 10:33 AM
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