So I have a NOS Holley 58mm throttle body, which is pretty much a Holley TB with nitrous ports build in. Anyway under normal driving conditions the TB will stick open 8% unless I let off the throttle fast or blip the throttle to get it to close 100%. Its killing gas mileage and my brakes.

So what can be done to get my TB closed under normal everyday driving?
I have read a few threads about fixing them, but everything I have done, besides adding a helper spring, doesn't seem to help.

Ive drilled holes for the spring to add more tension, but it didn't help. I also drilled a hole to let so air into the motor while idleing so the IAC motor isn't doing all the work.

I think it is vaccum related, cause with the motor off it will close all the way(verified with my scanmaster). The blades are not cantacting the throttle body anywhere so I dont know what the problem is or how to fix it.

I dont want to switch TB's cause I have spent many hours polishing this one and trying to get it to work properly and I dont want to add a helper spring if I can get away with it.

Anybody have any help for this?

 

A search should turn something up because the sticking is a well know issue with the Holley TBs.

 

Yeah I searched and I tried everthing I found, but it still stickes open so I was wondering if someone had any other fixes.

 

Mine was doing this also. I noticed the throttle cable was getting tight before the throttle would close all the way so i just unbolted the arm from the side of the throttle body and then positioned it where it would rest and then tightened it down.

 

I just had a very similar problem with my Summit 58mm TB. It would not close entirely unless I quickly blipped the throttle. Upon closer inspection, it turned out that the attachment point on the throttle body for the cruise control cable was in a slightly different position, as compared to the stocker. On my car (97) the adjustment thingy is located on the cruise control cable near the fire wall (it may be hidden by the brake booster).

Slide up the adjustment clip and the cable automatically lets out a bit as the throttle return springs pull out the cruise cable just a little. Then just slide down the adjusting clip and you are in business. On other year cars the adjustment may be different but you can look it up on Shoebox.

Good luck