My idle SUCKS! What can I do??

[BlueOvalStangGT]

I finally tried messing with the Tweecer again and the car just wont idle. I loaded the stock tune on, turned off the Smog and EGR, raised the idle to 850 and the car surges, stalls and just wont idle. What can I mess with? I tried resetting the idle the manual way and that doesnt work. Could my IAC be messed up? Bad Maf? Bad TB? What do you all think?

 

[bimmertech]

after you moved the set screw for the manual idle adjustment, did you reset your tps voltage? i assume it ran fine before you put the tweecer on it.

 

[Pokageek]

Hmm... I had a very similar problem. I went ahead and upgraded my TB to a ford racing 65mm b/c it was bigger than stock AND included the new components! But to answer your question, I would suspect these parts. You can do a volt test I guees, not sure how. Considering my components had 140+miles on themn, I just replaced and luck had it, I fixed it.

 

[BlueOvalStangGT]

No I did not reset TPS, I dont exactly have the tools. And no it didnt run fine before the tweecer. I actually have had idle problems since the supercharger has been on(almost a year) but now it just wont idle period. All thats needed for TPS is the voltmeter and the allen keys for the TB right?

 

[a50sn95]

Please go here and read my posts.
Basically I pulled the spout, and the ISC wire, and messed with the idle set screw and the other idle air screw on our throttle bodies to get it to idle at about 650. This is with my combo in my sig. It can be done, you just have to mess with them until it idles. Then I started data logging the airflow numbers at 100rpm increments (approx) to 2000 rpm using feeler guages between the screw and the lever to increase an hold each step.
I then shut it off, and picked middle airflow numbers for each number in the ISC Neutral Idle Airflow. I also used a middle number for my desired idle rpm for the TB Airflow scalar. After that you work on the dashpot preposition, to keep the car from stalling when you let off.
Basically these number tell the computer what it should see at these rpm's. So it tries to make your setup match these numbers. since you move alot more air, it's not enough, which causes the bad idle and stalling issues.
I use EEC Analyzer to help with most of the calculations, I HIGHLY recommend this piece of software. It scan your Tweecer datalogs, and points you in the right direction.
You can get it from here:
http://eecanalyzer.webhop.net/

 

[a50sn95]

BTW, you can set your TPS with your Tweecer. Just hookup your laptop, start datalogging (assuming you have the TPS voltage in your payload), and turn on the key, but engine off. The dashboard will show you your TPS voltage, and you can set it. Keep in mind it does not move as fast as when the engine is running so move it and wait a second for the display to change....
Dennis

 

[a50sn95]

Oh, I don't think you will ever get it to idle right until you do these steps. Mine turns heads because it sounds so wicked at idle (750 rpm, with a nice cam...)
I can't tell you how happy this one little thing made me....
Dennis

 

[BlueOvalStangGT]

Is it the ISC or the IAC you have to disconnect? Or is that a typo? Also I have EccAnalyzer but I dont know how to use it.

 

[final5-0]

Good info Dennis!

Those two items will go a long way to helping one obtain a stable idle.

Chris.........................

You getting this?

Grady

 

[HISSIN50]

Is it the ISC or the IAC you have to disconnect? Or is that a typo?

Grady taught me that the tuning guys refer to the IAC as the ISC sometimes (ISC = Idle Speed Controller).

 

[a50sn95]

Yes, in my head IAC=ISC and ISC=IAC....
There are only two wires running to the throttle body. One is the TPS and the other is the one I am refering to. I don't actually know the correct term....

 

[a50sn95]

Also I have EccAnalyzer but I dont know how to use it.

I use EEC analyzer like this:
First only work on one thing at a time!
Since my idle was the ONE thing that really pissed me off about the way my car ran, I started here.
First, if you have entered MAF info in tweecer, use the export MAF button in Caledit to export your MAF to a file. I named mine "mymaf.maf". Just use something you will recognize.
Then start EA, and go to the MAF tab and import the MAF file you just made.
Then go to the injector slopes tab and make sure your injector slopes are the same as what you have set in Caledit.
I ALWAYS check to make sure these are done before I open a datalog in EA. Otherwise, it'd be a waste of time if you caught it later, or a BAD adjustment if you never caught it.
Then, open the datalog you want to use for this. I assume you have a tune with datalogging enabled, and have datalogged already.
If are working on something specific, there are help buttons on each tab of EA that will tell you what needs to be datalogged in order for it to make the calculations.
The help tabs ALSO tell you the steps you need to take. For instance, everything I put in my first post is in EA on the ISC (I think that's what it's called) tab. Go to that tab, and click the help button, and it will tell you how to do it. That is where I got my information from to do it on my car....
Are you spending any time on the tweecer forum?
tweecer.oplnk.net
Lots of help there, too, and Clint (EA's author) spend alot of time there....
Finally, just make sure you work on one thing at a time.....
I've been working on my MAF numbers, and my low end numbers have changed, which means all my idle adjustments are off a bit. It still idles just fine, but I know I need to go back and revisit it. But now, it will at least idle in the driveway without dying, something t wouldn't do before.....
Dennis

 

[a50sn95]

Oh, one last thing. I bet if you just simply plugged in the numbers I have posted in that link I gave you in my first thread (here ), and write it to your tweecer, it'll idle better than the stock tune does...
It won't be exactly right as I have a bigger MAF and TB, but it'll be closer than stock.
It'd only take a minute to try....

 

[a50sn95]

One more last thing....
I notice you have 36's. I was seeing max'd duty cycle on my 36's in CalCon, which is why I bumped them up to 42's....
Just make sure you look at the duty cycle sometime when you do a WOT pull.....
Dennis

 

[VibrantRedGT]

Data Log and it should tell you your TPS setting. It needs to be in the .92-.98v range at idle. If it's lower or higher it will surge. You don't need tools for this right now. Report back the numbers.

 

[BlueOvalStangGT]

Aye Aye Captain!My last class is at 5:15 so ill try to run out to my car after that and check it.

 

[CManT1914]

Good info Dennis!

Those two items will go a long way to helping one obtain a stable idle.

Chris.........................

You getting this?

Grady

Well if you're referring to me, then yes I've been keeping my eye on this post. My idle is somewhat stable, but it's at freaking 1000 rpms!! Then when I push in the clutch while coasting, it surges between 1200 and 1500, and continues like that for about 10 seconds after I fully stop. Very irritating. There are so many little things I need to redo with the stang, and I just haven't had any time to do them. Hopefully this weekend I can get something going with it again.

 

[BlueOvalStangGT]

I just tried datalogging and I cant get CalCon to work. When I try to open it it says " is not a valid integer value. Then it loads up but none of the gauges do anything and i cant datalog anything. Thiis is my first time using the new version so is there something im doing wrong here?

 

[CManT1914]

I just tried datalogging and I cant get CalCon to work. When I try to open it it says " is not a valid integer value. Then it loads up but none of the gauges do anything and i cant datalog anything. Thiis is my first time using the new version so is there something im doing wrong here?

First time using the new version?? You might need to transfer your tune from the old version of CalEdit to the new one (I'm assuming you're using new versions of both, whereas you weren't before?) and redo your payloads. I get that integer error too, nothing to worry about there.

 

[BlueOvalStangGT]

What? Im using the stock tune.....