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Rawknees'Turbo Rawknees'Turbo is offline
Mighty Meatlocker Turbo
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Join Date: Apr 2016
Location: North TexASS
Posts: 15,546

Pud, nope. The idle increased when you did that because the small hose is attached to a vac nipple that is below the throttle plate, and by removing the hose and running the engine with it open, unmetered air entered the primary intake manifold (acted like a second, throttle air bypass/idle screw).

When that hose is attached, and if the vac limiter is working correctly, during closed throttle, the diaphragm in the vac limiter is pulled back in such a way that unmetered air is allowed to pass into the primary intake manifold (by way of the two bigger hoses), after the throttle plate - this is what causes the engine rpm to drop so slowly during closed throttle. Usually when they go bad (tear in diagram, corrosion inside, etc.), air leaks past at all times and you end up with a high idle that you can't adjust - usually worse when engine is hot.

Last edited by Rawknees'Turbo; 01-16-2017 at 10:38 AM..
Old 01-16-2017, 10:35 AM
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