Throttle Body Idle Issue

[Stalker]

Hi all,

Before I start, I have searched for this problem and followed the numerous recommendations detailed in a number of posts. That said, I got the itch this weekend to switch out my throttle body. I bought the billet flow part a while ago and just couldn't see it sitting on my shelf any longer. The install went pretty smoothly and I tried to follow Billet flow's instructions as well as I could. Although between the old instruction sheet and the revised ones that came with the part, they were a little confusing. However, that is beside the point. The part was mounted and the car runs. I have tried to adjust the idle using both the supplied instructions and the other methods mentioned on these boards. And I have partial success. When I start the car up, cold or hot, it will drop down to ~750 rpm idle. The problem is that the car doesn't want to drop down to that idle when coming to a stop. The idle seems to stick at ~1500-1750 and if I rev a couple of times will drop down to ~900 rpm. Eventually the SES light comes on (as expected for a high idle).

The last method used to set the idle involved removing the IAS and blocking the holes. Adjusting the throttle stop till the car idled at ~750 rpm. Then reattaching the IAS and setting the TPS to ~.98v. My only other observation, other than the idle, is a slight stickyness to the throttle pedal when coming off zero throttle. I assumed this was probably some sort of vacuum effect caused by the oval TB.

Does anyone have any suggestions or thoughts on what to look at to fix this? On the intake side I have the Steeda CAI, stock MAF, Billet flow TB & Plenum. I am running a stock chip.

Thanks for any help.

 

[NightEnforcer]

1st Trade it in for and Accufab throttle body. Just kidding. Doug makes a good product. Call him Tuesday. He will walk you through it or replace it if there is a problem. Did you disconnect the battery after installation and allow the computer to reset? Hit the brakes while the batterey is disconnected as well. I left mine off for about an hour and then followed the connection procedures as outlined in the owners manual. Then you need to drive the vehicle for about 20 to 30 miles to allow the computer to relearn. It is my understanding that the the computer actually adjusts the idle after the initial settings are aquired.

 

[§ilver§nake]

Originally posted by NightEnforcer
...Then you need to drive the vehicle for about 20 to 30 miles to allow the computer to relearn. It is my understanding that the the computer actually adjusts the idle after the initial settings are aquired.

DITTO.

 

[Stalker]

Yeah.. I reset the computer in between each step, per the instructions. This basically involved disconnecting the negative ground and turning on the lights for a few minutes. I am pretty sure that I am doing that correctly, as the SES light gets reset and all the gauges go through a reset sequence when the power is reconnected. As for the driving, I went out for about an hour just to make sure the EEC had a chance to adjust to the new settings. I would think that I had a vacuum leak, but the car WILL idle at 750. It just has problems coming down off revs.

 

[03 DSG Snake]

I had problems with the idle on mine, sent it back to be "revised", put it back on. Then got sick of it and bought the Accufab..

 

[ALA G8R]

You might want to try a return spring to force the single blade butterfly closed. Sounds like you are getting too much air that is causing the high idle.

 

[03 DSG Snake]

Originally posted by ALA G8R
You might want to try a return spring to force the single blade butterfly closed. Sounds like you are getting too much air that is causing the high idle.

The spring has so much tension on the BF, that it actually increases pedal effort somewhat. That should be plenty of spring?

 

[Stalker]

what's wierd is that it's so predictable. Coming off of revs it will stay at 1750 then I pump the throttle and it will drop to 1500. If I pump the throttle again it will drop to 900. I would think it was a air leak execpt for the predictability.

 

[sambandit]

Do you have a new gasket between the new plenum and back of the supercharger?? When I put my accufab on, I didn't replace the gasket. I had very similar problems for a week until I figured out it was just a vacuum leak at that location!! I would search for vacuum leaks first!

 

[Stalker]

I thought about that. I do have a new gasket there. I didn't do anything special with it, however. Just a simple paper gasket. Wouldn't a vacuum leak through the gasket keep it from ever idling at 750?

 

[Stalker]

I just went out and started it up. Got the idle up to 1500 then got under the hood and looked at the throttle position. Floating above the stop screw. I could manually close the throttle and the idle went right down to 750. Maybe the return spring isn't strong enough? Obviously the blade is partially open and this is dictating my idle speed.

 

[jumpincactus]

Seems I remember that 03 Rocks had this same issue when the not to be mentined TB first came out last year. Thought the fix was a stouter spring...........................

 

[NightEnforcer]

Did you talk to Doug yet? It sounds like a bad TB.

 

[Stalker]

I've PM'd him... waiting for a response. If I don't hear from him tonight then I'll dig up the phone # and try to give him a call.

 

[MidLifeC]

Give Doug a chance to reply, he sometimes works late in his shop.....

 

[CobraBob]

You've got to give the computer a couple of days to adjust to the new throttle body. When I installed my Accufab I had a slightly higher idle and a slow return to idle. But after about two days the idle returned to the stock setting and the return to idle went back to normal. It's been fine ever since. By the way, I didn't touch the voltage setting. Didn't really have to. I just let the computer adjust.

 

[dougwg]

Originally posted by Stalker
I just went out and started it up. Got the idle up to 1500 then got under the hood and looked at the throttle position. Floating above the stop screw.

Floating??

It can't do that, you will have a high idle...

... raise the stop screw to meet the lever and reset your computer...just like it says in the instructions..

I'm here right now...I'll be here all frigin night working on a hot job...gimme a call if you like...

P.S. Looks like a 28 hour day for me....

 

[Stalker]

I've tweaked it a little and it is better. I'll make some more small adjustments and then give it a couple of days to see if it settles down. One more question for you: Is it expected to have the SES light on after the idle is as good as it's going to get? Do I need to invest in a code reader to clear the error codes? I've been waiting for the predator. But driving around with the SES light on is kind of a drag. And forgive the noob question. But if I clear the error codes for high idle, is this something I am going to have to continually clear until I get a new tune on the engine?

 

[ALA G8R]

You should expect to idle just like stock, nor should you accept it. I wouldn't accept living with the SES indicator continually coming on. Then you will tend to ignore the SES light when it comes on for some other reason.

Autozone will read the OBDII codes for free. The SES indicator can be reset by disconnecting the battery.

Peace.

 

[CobraBob]

Originally posted by ALA G8R
You should expect to idle just like stock, nor should you accept it. I wouldn't accept living with the SES indicator continually coming on. Then you will tend to ignore the SES light when it comes on for some other reason.

Autozone will read the OBDII codes for free. The SES indicator can be reset by disconnecting the battery.

Peace.

Good advice! :beer: