c4 Throttle body
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3rd Gear
Joined: Apr 2012
Posts: 3
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c4 Throttle body
Have 85 w/standard TB - While driving sometimes it will stick at a high idle a simple tap on gas pedal will drop it- but it is annoying- TB was cleaned thoroughly. Should the two plastic sides be joined or how far apart should they be? I think my problem lies with the spring assembly-
Thanks
Thanks
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Joined: Aug 2012
Posts: 75
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From: Lubbock, Texas
I just yesterday dealt with the exact same issue on my 90. I tried cleaning and adjusting and looking for vacuum leaks, etc.
What finally did the trick was to take the throttle body off the car, a ten minute job, and, after cleaning it thoroughly, smooth the bores where the butterflies close with 600 and polish the edges of the butterflies, removing the sharp edges. Before I did this, it would not only stick at high idle as you describe, it was also sticky coming off idle, making it very difficult to launch smoothly. Also felt crappy as a result. I'm very happy with the results; feels like it should now. All told, took about 45 minutes and half a sheet of 600 cut in band-aid sized strips. The 600 leaves a nice shiny smooth surface and doesn't remove any appreciable material.
What finally did the trick was to take the throttle body off the car, a ten minute job, and, after cleaning it thoroughly, smooth the bores where the butterflies close with 600 and polish the edges of the butterflies, removing the sharp edges. Before I did this, it would not only stick at high idle as you describe, it was also sticky coming off idle, making it very difficult to launch smoothly. Also felt crappy as a result. I'm very happy with the results; feels like it should now. All told, took about 45 minutes and half a sheet of 600 cut in band-aid sized strips. The 600 leaves a nice shiny smooth surface and doesn't remove any appreciable material.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
If the throttle only sticks while the engine is running ,then this is most likely your cause
