i have a 58mm BBk tb that is giving me problems. the car idles great but when i touch the gas it sticks around 1200-1500 rpms. i have to hit the gas to get it to come down.

the idle screw is backed off and the TPS is within the normal range. when it hangs open you can see the stop is off the idle screw and you can push it closed but it opens just a hair when you take your finger off the stop. if you shut the car off when its stuck around 1500 you can watch the throttle close back up. with the car off it works perfect

 

no ideas other than BBK's suck?

 

How is the return spring tension? I know that has been a problem on the Holleys, and there is an extra hole or two that allow you to increase the spring tension.... which helps sometimes. Not sure it the BBK is the same with regard to the extra holes.

 

I have a ported stock tb and mine was idling high too. I compared it to another stock tb and on the stock one that idled right, the stock one's stop screw actually extened out further OR it held the TB ever so slightly open more.
So I removed the ported TB and took a 15 torx driver and screwed the stop screw to hold the blade open further about 2-3mm more. Problem is solved now. NO more high idle. I surmise that the IABPS and TPS sense that the throttle will drop too low and i the IABPS holds it open.
Just a guess.
Might wanna give it a try.
Also check for leaks in your tubing prior to the MAFS/TB

 

My holley did the EXACT same thing. The solution? I just lubricated the shaft passages at all the locations (4) where it passes through the housing. I used some graphite lubricant and some penetrating oil. About a year and a half latter NO problems. Adjusting the spring is also a simple solution.

 

yea, I would have to say that you should lubricate the shafts and adjust the spring tension. That should fix the problem

 

thanx guys. i was gona try adjusting the spring. it does feel pretty weak compaired to the stocker.

its lubed pretty good but i add more.

the stop screw is backed way down. when i first start it she idles right around 800.

 

I have the same problem with my 58 mm BBK. It sticks sometimes. Since I have a 6-speed, it doesn't make a whole lot of difference. I just have to rev it on occasion to get it to drop. It seems to do it mostly when cold. Once it warms up, the shaft seems to move better and it works fine.

BRAD