Retune after 58mm TB install.
Thread Starter
Registered User
Joined: Apr 2005
Posts: 1,830
From: Colorado Springs, CO
Retune after 58mm TB install.
I installed my new NOS Holley 58mm TB the other day and i've noticed it seems to be running richer. I can really smell it now, whereas before it was barely noticeable. Also I have lost about 2mpg with the same driveing. Could this be because by the new TB or does this colder winter air have anything to do with it?
My TPS at idle is around .66 and about 4.00 at WOT. I think it was about .68 stock, but it is still within specs. Sometimes the throttle stickes open 1%, it only does this with the engine running so i'm assumeing its vacuum related. I already have it set to the strongest blade return spring setting. I have checked to make sure the blades are not makeig contact with the houseing and holding it open, and i have greased the shaft where it makes contact with the houseing. Is there anything else I can do to get it to close all the way?
My TPS at idle is around .66 and about 4.00 at WOT. I think it was about .68 stock, but it is still within specs. Sometimes the throttle stickes open 1%, it only does this with the engine running so i'm assumeing its vacuum related. I already have it set to the strongest blade return spring setting. I have checked to make sure the blades are not makeig contact with the houseing and holding it open, and i have greased the shaft where it makes contact with the houseing. Is there anything else I can do to get it to close all the way?
Thread Starter
Registered User
Joined: Apr 2005
Posts: 1,830
From: Colorado Springs, CO
I dont see how drilling another hole would solve anything since my IAC are on par. And i have it set to the tightest spring position possible. I even drilled another hole for more tension but it had too much tension and the ABS module was not pulling up the slack in the line, so it would only open to about 40% throttle even thouugh it was floored.
A guy at Holley recomended that I start the car up with the TB on, looses the blade screws and then tighten them back down to see it that would fix it. He seems to think that the vacuum is makeing it bind somewhere, causeing the blades not to close all the way. I havent tried this yet, but I guess I could the next time im in there.
A guy at Holley recomended that I start the car up with the TB on, looses the blade screws and then tighten them back down to see it that would fix it. He seems to think that the vacuum is makeing it bind somewhere, causeing the blades not to close all the way. I havent tried this yet, but I guess I could the next time im in there.
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Joined: Oct 2002
Posts: 2,277
From: Orange Kounty, Kalifornia
Re: Holley or BBK Throttle Body
--------------------------------------------------------------------------------
My problem with the borrowed BBK I had was that the IAC air passage on the back of the TB has ports cut in it to open it to the main plenum as shown here in the 2nd and 3rd pic down on this page:
http://members.***.net/chipsbyal/page/idle/index.html
That made my idle quality terrible...knowing that the Holley has some issues to I elected to go with the Holley because the IAC passages are just like the stock ones so that each cylinder gets idle air from the little bleeder holes in the runners...
What I did with the Holley to get it to work properly:
1) Drilled a small venturi hole in the IAC passage to mimic the stocker design..also shown in that link above.
2) Wound the return spring an additional 1 turn because the vacuum from the engine would keep the blades from closing when coasting down the road and sometimes at idle..see my other post on this...I just fixed this just now not even 10 minutes ago!.
*
Bottom line is I need to design & make a TB that is correct..its ridiculous that for $300-400 no one can make one that is flawless for our cars...and I never did get an answer as to if the AS&M ones have the passage like the BBK or not..that was another thread in the past couple of weeks....search on my id and you'll find a few posts/threads about this...
--------------------------------------------------------------------------------
My problem with the borrowed BBK I had was that the IAC air passage on the back of the TB has ports cut in it to open it to the main plenum as shown here in the 2nd and 3rd pic down on this page:
http://members.***.net/chipsbyal/page/idle/index.html
That made my idle quality terrible...knowing that the Holley has some issues to I elected to go with the Holley because the IAC passages are just like the stock ones so that each cylinder gets idle air from the little bleeder holes in the runners...
What I did with the Holley to get it to work properly:
1) Drilled a small venturi hole in the IAC passage to mimic the stocker design..also shown in that link above.
2) Wound the return spring an additional 1 turn because the vacuum from the engine would keep the blades from closing when coasting down the road and sometimes at idle..see my other post on this...I just fixed this just now not even 10 minutes ago!.
*
Bottom line is I need to design & make a TB that is correct..its ridiculous that for $300-400 no one can make one that is flawless for our cars...and I never did get an answer as to if the AS&M ones have the passage like the BBK or not..that was another thread in the past couple of weeks....search on my id and you'll find a few posts/threads about this...
http://web.camaross.com/forums/showt...ghlight=holley
Thread Starter
Registered User
Joined: Apr 2005
Posts: 1,830
From: Colorado Springs, CO
I guess I could see how drilling a bleed hole would help now. I read through that and now have a better understanding of why it was doing this. The next time I have the TB off, i'll probably do this.
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