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throttle plate adjustment?

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Old May 30, 2010 | 01:14 PM
  #1  
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Default throttle plate adjustment?

Does anyone know how to adjust the throttle plate mechanism?

Picture is from Dwaynes intake epic
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Old May 30, 2010 | 01:44 PM
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You shouldn't need to adjust that stop, it has been set to allow the correct amount of residual air through to allow the ISV to control idel OK.

But if you fit a new throttle switch, the mounting tabs are slotted to allow correct operation.
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Old May 30, 2010 | 02:37 PM
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I wouldn't adjust it John except for the fact it appears to have been backed off, perhaps in effort to reduce the high idle.

I'm thinking of rebuilding the throttle body with new sealed bearings. As mentioned the mechanism was bent to the point that when the throttle was opened beyond 3/4 the mechanism scraped the throttle body.
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Old May 30, 2010 | 02:41 PM
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I have always set them to where you can just see a sliver of light under the plate with a light source on the other side, do not let it go fully closed or it will develop a hard spot in the throttle after a while.
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Old May 30, 2010 | 06:11 PM
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Took some pics of the t.body then removed the TPS.

The throttle plate shaft has some movement indicating a possible bearing failure and also the bearing is not recessed as shown in Dwaynes intake epic. Assuming the t.bodies from the S4 to GT are same the bearing is then in a displaced position.
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tplate shaft 001.JPG (127.9 KB, 438 views)
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tplate shaft 002.JPG (118.8 KB, 358 views)
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tplate shaft 003.jpg (37.7 KB, 386 views)
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tplate shaft 004.JPG (109.8 KB, 389 views)
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tshft brg 001.JPG (116.4 KB, 401 views)

Last edited by the flyin' scotsman; May 30, 2010 at 06:51 PM.
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Old May 31, 2010 | 12:42 AM
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Though its hard to see in the previous pics the outer spring is not in the correct position. Also the inner plastic piece was broken.

When the shaft was pulled one of the 'wavy' washers was missing.
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tbody springs shaft etc 001.JPG (145.2 KB, 376 views)
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tbody springs shaft etc 003.jpg (45.6 KB, 386 views)
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tbody springs shaft etc 004.jpg (50.7 KB, 392 views)
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Old May 31, 2010 | 01:58 AM
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if your this fa,
r make sure that the nut stop is on the roll pin for the flappy stop.
its best to tap the stop onto the roll pin instead of trying to twist the nut head as the roll pin can shear off.
A dab of green loctite after things are adjusted will keep the nut stop in place
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Old May 31, 2010 | 12:57 PM
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Not sure I got your point stan...............the car is a '90 GT and has an off centre bolt for the flappy stop.
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