LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Help!!!

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Old Apr 16, 2010 | 10:49 PM
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Ok guys, I just installed a set of 1.6 rr, a bbk 52mm tb, as well as a full tune up on my wifes car.Now it is idles about 1900rpm. I have set the adjusted the tps, the iac counts are good, the idle screw it adjusted all the way, and I can not find a vac leak. Idle in the tune is set at 900rpm. Any help would be great I am at a loss and it is driving me nuts.
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Old Apr 16, 2010 | 11:09 PM
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Does the idle change as you loosen the screw on the throttle body when the car is on or is it a constant 1900rpms no matter what?
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Old Apr 17, 2010 | 07:47 AM
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Constant.
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Old Apr 17, 2010 | 08:30 AM
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What brand TB and did you buy it new or used? also did you clean the tb?
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Old Apr 17, 2010 | 08:38 AM
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bbk, new, and yes I cleaned it with tb cleaner before I installed it.
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Old Apr 17, 2010 | 09:36 AM
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Thats your problem. You are not supposed to clean the BBk's with TB cleaner. BBk's have a coating on the TB blades and if you use TB cleaner it takes the coating off and causes high idle. It was in the the paper work I got with my used 52mm.
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Old Apr 17, 2010 | 10:01 AM
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You sure there are no vac leaks? Is the IAT back in?
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Old Apr 17, 2010 | 10:13 AM
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1900 rpms isn't going to be caused by a coating being cleaned off. Start with the adjustment screw backed out all the way (blades 100% closed). Set the IAC so that the voltage is about .45v-.55v If it's still idling at 1900 you MUST have a vacuum leak somewhere. You can spray carb cleaner around the intake, when you spray near the leak you will hear the idle change...look in that area for a leak.

maybe take some pics and post em up.
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Old Apr 17, 2010 | 11:20 AM
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The coating quite thick on the edge of the blade, it will cause this. It is in a document by BBK that came with mine that said DO NOT USE TB CLEANER. The use of TB cleaner will remove a coating from the outer edge of the TB blades and cause a high idle condition. If my box wasn't packed away in storage I get the paper out and show you but I know for a fact MY BBK TB has a coating on the outer edge of the TB blades (it's black) and you are not supposed to use TB cleaner on them. Mine is at least 3 years old so I don't know if they have changed it but You are talking about the outer edge of the blades with a coating farley thick, I asure you it will cause a high idle.
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Old Apr 17, 2010 | 06:39 PM
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Originally Posted by jaycenk
Thats your problem. You are not supposed to clean the BBk's with TB cleaner. BBk's have a coating on the TB blades and if you use TB cleaner it takes the coating off and causes high idle. It was in the the paper work I got with my used 52mm.
I did not spray the blades.

I checked again for leaks and found a small one that I took care of, the rpm's did drop down to 1500-1600. So I thought I would put the stocker back on and it didnt help,still at 1500-1600.

I have never had this kind of problem for so long it is driving me nuts.
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Old Apr 20, 2010 | 07:17 AM
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Any updates im having the exect same problem
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Old Apr 20, 2010 | 05:35 PM
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Nothing new I havent had a chance to really work on it anymore
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Old Apr 21, 2010 | 01:00 AM
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Is the thotle cable hanging it open a bit? Is the linkage stop sitting flat on the TB stop?
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