Wanna screw? (tb)

[ShiftTheDrift]

Can anybody help me identify this screw and it's purpose on a BBK 70mm throttle body? The last person who worked on this didn't have a "clue" as to what it did, therefore, he turned every way possible, .

All I'm attempting to do is change the idle and I get an answer from BBK if my life depended on it. So what I'm asking is what screw does what and by turning one screw, do you have to compensate by turning the other screw? It's frustrating when you can't even get cooperation from the people that manufacturer the damn thing. In my opinion, BBK Performance has the absolute worst technical support I've ever seen!

 

[SN95StangMan]

The one on the right is the one you want to use to adjust the idle. If you try to move the other screw it will probably give you a funky idle.

 

[ShiftTheDrift]

I'm assuming, because the image is on it's side, the right screw is the one I'm talking about?

 

[SN95StangMan]

Yea, that screw and the thing next to it on the TB is the IAC (idle air control). Unplug it, then turn the screw, plug it back in, and check your idle.
And BBK doesnt have the worst technical support ever, that honor belongs to Saleen.

 

[ShiftTheDrift]

Gotcha..

Just in case the "throttle plate screw" was adjusted, do you know the preset from the factory?
I think it's completely whacked. Thanks Eddie!

 

[ShiftTheDrift]

UPDATE

I got a call back from BBK's technical support and here's what they had to say:

The flathead screw next to the TPS serves no purpose and should be all the way closed. The only reason BBK manufactured this screw into this particular model is because the stock TB included one. Idle adjustments should be made using the 3mm Allen screw only. The new throttle bodies do not include this flathead screw next to the TPS.

Make sense to anybody?

 

[95BLBLVert]

If you adjust the idle screw you need to check the voltage reading of the TPS and readjust as necessary. You can search for a post on how to properly do this.

 

[ShiftTheDrift]

During my lunch, I closed the flathead screw all the way as BBK instructed me too, obviously making note of where it was at originally.

Now, the damn car won't stay running. I've cleared all the tables in ECU by disconnecting the battery and it runs for about 10 seconds...then dies.

I'm lost and I think BBK is full of sh**.

 

[ShiftTheDrift]

If you adjust the idle screw you need to check the voltage reading of the TPS and readjust as necessary. You can search for a post on how to properly do this.

Why would the voltage change if you're adjusting for idle?

 

[95BLBLVert]

Because when you turn the idle screw you are also turning the butterfly shaft and in turn changing the postion of the tps.

The other screw I believe affects the amount of air bypassed around the butterfly. I would back the screw out until its flush with the housing and then see if it idles properly.
Ford put that there for a reason.

 

[ShiftTheDrift]

Okay, my research shows the TPS sensor is not adjustable on 94/95s.

 

[Rootus]

For the IAC screw, close it all the way, then back it off one or two turns.

For the other one, I'd adjust it so that it stops the butterfly just before it hits.

To adjust the idle properly, use a chip or tuner.

Dave

 

[ShiftTheDrift]

Sounds good.. I do have a custom chip programmed by JMS. The chip's documentation indicates idle at 850. The big problem I'm having is the idle sticks between 1500 and 2000 rpm at rolling stop. For example you pull up to a stop sign, it might take roughly 5 to 8 seconds to stabilize.

Regardless of this chip's idle set to 850, the engine still idles at 1000 no matter what.

Perhaps I should have mentioned this earlier? This is ultimately what I'm trying to get solved.

 

[mytight95]

Then plug it back in doe as hairy stated and adjust the TB butterfly screw just before the TB shuts. you will have to unplug the IAC motor the allen screw is attached to sorta, and adjust the idle to around 850 rpm. by turning the allen counter clockwise, you will raise the idle. Don't worry about the voltage on the tps, the computer will conpensate that coltage and bring it down to a normal idle. The iac motor acts as a supply for air for the car, kinda pumps air into the tb by a little plastic pieces that fluctuates open to closed.


bbk was right in their instructions *sorta*


jason

 

[ShiftTheDrift]

Well, I'm getting off work and printing this thread out...
I'm gonna go try what you all suggested and I'll post my results in the morning. Thanks again!

 

[Rootus]

The big problem I'm having is the idle sticks between 1500 and 2000 rpm at rolling stop. For example you pull up to a stop sign, it might take roughly 5 to 8 seconds to stabilize.

Hanging idle is a bitch to solve sometimes. It's not uncommon to meet people using tuning devices that are unsuccessfully trying to battle hanging idle problems, because there are so many things that can cause the EEC to behave that way. I would pull codes to make sure it isn't something obvious, and then talk to JMS since they burned the chip. There are settings in the EEC calibration that specifically affect idle decay rate, and then things like timing & fuel delivery can also have a pronounced effect. The downside of a mail order chip is the inability to tweak things realtime. The upside is they ought to know by now what they're doing .

Dave

 

[ShiftTheDrift]

Well, I started on this with a buddy at 5:30pm, pst and now walking through the door of our apartment, it's now 1:38am. I'm about ready to say screw it. I can't get this damn thing to idle for sh**. I've tried everything this thread presents, plus more and no matter what, the car either dies, idles at 1100 rpm with the a/c and lights on, or it idle hunts. This problem is pushing me to the limit. EFI systems can kiss my ass!

Since I have to work today, I'm exhausted and I'm going to bed.

 

[94TURBO5 O]

Funny thing is I have the same problem with hanging idle and I just live with it. I also have ajusted that screw to get my idle right. hmmm?? Maybe I need to close it and just ajust the idle screw alone.
Just stay calm man and it will work out for you. It gets frustrating as hell to own a Stang sometimes but its so worth it everytime its running mint and you spank some azz!

 

[ShiftTheDrift]

Well damn it, I called JMS and they want the chip sent back for review.

In the meantime, can anybody recommend a better TB, other than BBK for my car?

 

[go.rei GT]

Note to self: use sexual innuendos in title, when wanting people to view your thread. 232 views, jeez...