My idle SUCKS! What can I do??

CManT1914 · Sep 13, 2005

BlueOvalStangGT said:
What? Im using the stock tune.....

Then it's even easier. You'll need to go into whatever version of CalEdit that works with your version of CalCon you're now using, and redo your payloads, and rewrite the twEECer. I think I was having problems switching back and forth between versions of CalCon. Whatever version of CalCon opens when you hit the button in CalEdit, that's the one you want to use.

BlueOvalStangGT · Sep 13, 2005

Ok got it to work, TPS with the car off and my foot off the pedal is between 1.04-1.05.... Im guessing I found my problem! Do I just need to turn my TPS until its under .98? My Pro Products throttle body has two allen screws you can loosen to change the TPS but I thought it was unadjustable on our cars.

a50sn95 · Sep 13, 2005

Yes, I have the PP tb and that is what you do. I have mine set at .985
I don't think this alone will fix your idle issues, though...
Dennis

VibrantRedGT · Sep 13, 2005

Leave the data log running, loosen the screws on the TPS. Try moving, tightening, moving, tightening until you can under .98. Mine has been set at .94v for years and I've never had an idle problem. If you can't get it under then the TPS needs to come off and some metal needs to be shaved so the TPS can move easier.

BlueOvalStangGT · Sep 13, 2005

Well I adjusted it... had it at .97 and I put it back together. No one told me I have to back the idle screw all the way out when doing this! I backed it out to reset my idle and then the TPS voltage was like .8 something. It was getting late and im using the worst tools for the job(all I can get for now) so I gave up for today. I screwed the idle screw back down so the voltage would be at .98 cause I figured that would be better. Now when I start the car, it wont really stall(well it hasnt YET) but it still has a crazy surge from 600-1600 rpms. Thats not the worst of it, I was driving the car home and at certain rpms the car will shake( is this bucking??) horribly. Like the car will bounce back in forth like I was slamming on the gas and letting off but 293 as fast. I have to slam in the clutch and try another gear so it doesnt do that. Its really bad, I dont know what causes it but I need to figure this out. Tomorow im gonna try this again so we will see. Oh and im getting 14 mpg HIGHWAY now too, its fun.

a50sn95 · Sep 13, 2005

CManT1914 said:
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.

These are exactly the issues I was having. I also had an occasional stalling issue that would go away for a while, but as the computer learned, it came back
Get the TB Idle Airflow first. This will help get your idle down to where you want it.
Then work on the ISC Neutral Idle airflow for the surging and the dashpot preposition to help if you have a stalling issue.
The idle screw is supposed to be set by backing it all the way out, and then turning it back down until it touches, and one full turn more. You also have a screw that allows air to bypass the ISC/IAC. You can use this for more air if need be. You can also go more on the idle set screw, but the preferred method is one turn past contact. The idea is to keep the IAC/ISC duty at around 34% at idle....
At least this is how I understand it...
Someone else chime in...
All of this in on http://tweecer.oplnk.net/ if you search long enough. It's also in Clint's EEC Analyzer program.....
Dennis

CManT1914 · Sep 14, 2005

a50sn95 said:
These are exactly the issues I was having. I also had an occasional stalling issue that would go away for a while, but as the computer learned, it came back
Get the TB Idle Airflow first. This will help get your idle down to where you want it.
Then work on the ISC Neutral Idle airflow for the surging and the dashpot preposition to help if you have a stalling issue.
The idle screw is supposed to be set by backing it all the way out, and then turning it back down until it touches, and one full turn more. You also have a screw that allows air to bypass the ISC/IAC. You can use this for more air if need be. You can also go more on the idle set screw, but the preferred method is one turn past contact. The idea is to keep the IAC/ISC duty at around 34% at idle....
At least this is how I understand it...
Someone else chime in...
All of this in on http://tweecer.oplnk.net/ if you search long enough. It's also in Clint's EEC Analyzer program.....
Dennis

Yea I had read that sometime on eectuning.org, but at the time had a big vacuum leak that was basically negating all my work. I THINK I'm good on vacuum now, but I'm gonna hook up a gauge this week hopefully to confirm it. I just registered my EEC Analyzer, and I gotta say, that's way more information and power than I will ever need, lol.

BlueOvalStangGT · Sep 14, 2005

Did you just say to set idle first? How can I set TPS if the idle screw is already down a little? I cant even get it to idle long enough for me to mess with the idle screw.

a50sn95 · Sep 14, 2005

It's a pain in the A**. It helps to have someone who can punch the throttle for you while you work on the adjusting. I did it by myself, but MAN, I must have started it 50 times.

Here is a picture of the TB.
You have to mess with the Setscrew and the bypass to get it to idle, to do these adjustments.
i adjusted the set screw as described, and ended up unscrewing the bypass screw WAY out to get it so it would idlelong enough for me to get around to the front of the car. THEN I started messing with them (closing down the bypass screw and bumped up the set screw to about 2 turns) until it would idle down to about where I wanted it (750). THEN I set the TPS. Then I worked on the rest of the stuff to get the idle nice and smooth, and eliminatemy stalling issue....

final5-0 · Sep 14, 2005

a50sn95 said:
These are exactly the issues I was having. I also had an occasional stalling issue that would go away for a while, but as the computer learned, it came back
Get the TB Idle Airflow first. This will help get your idle down to where you want it.
Then work on the ISC Neutral Idle airflow for the surging and the dashpot preposition to help if you have a stalling issue.
The idle screw is supposed to be set by backing it all the way out, and then turning it back down until it touches, and one full turn more. You also have a screw that allows air to bypass the ISC/IAC. You can use this for more air if need be. You can also go more on the idle set screw, but the preferred method is one turn past contact. The idea is to keep the IAC/ISC duty at around 34% at idle....
At least this is how I understand it...
Someone else chime in...
All of this in on http://tweecer.oplnk.net/ if you search long enough. It's also in Clint's EEC Analyzer program.....
Dennis

Official Chime In

That is pretty much what I've done

Grady

final5-0 · Sep 14, 2005

BlueOvalStangGT said:
Did you just say to set idle first? How can I set TPS if the idle screw is already down a little? I cant even get it to idle long enough for me to mess with the idle screw.

Use feeler gauges between the blade stop screw and linkage.

Grady

BlueOvalStangGT · Sep 14, 2005

I dont have access to feeler gauges until I get home(could be for weeks). If im opening the TB a little to set idle, wont that give me faulty TPS readings since the TB blade is open a little already? How am I going to know what to set my idle to if its constantly surging and wont stay still? What has the approximate width of a .1(or was it .01) feeler gauge?

BlueOvalStangGT · Sep 14, 2005

BUMP, I have the tools now, as soon as the car cools down im going to work on it. What should I set first, TPS or Idle screw? How should I set idle if I dont have feeler gauges?

a50sn95 · Sep 14, 2005

Yes, your tps voltage will change every time you move the set screw. You should be able to get it to idle, though, and set the TPS after you have it close. I know it seems like a Catch-22, but YOU put the mods on your car, so you have to go through these steps to get it adjusted. You are now flowing a lot more air, even at idle, so you have to find the right settings, and numbers to put in the Tweecer in order for the calculations that the computer makes to work properly.

Here's an example (the numbers are made up, since I don't have them in front of me, but you'll get the idea)
The Stock J4J1 bin file looks for about 35kg/hr of air at idle. That's what is programmed in. You put on a 75mm TB, cam, heads, intake and now the engine needs 48 kg/hr. Since the computer expects it to idle at 35, It tries to cut airflow (probably through the ISC) and retard timing to make it match the 35. Your engine will try to die, the computer will see this, open the ISC back up, bump the timing, and whatever else to keep it running, and then try to back it back down to 35 again. Until you tell the computer thatit needs 48, it will try to make it work with 35. Please note that I just simplified the process, as there are LOTS of other things that it uses to calculate idle, I was just trying to illustrate some of what is going on.

I have mine all set, and now I'm altering my MAF transfer at idle because it idles too rich. These changes are affecting the OLD numbers I put in the Tweecer for TB Airflow and so on. So, once I get the MAF right, I'll have to re-do the idle numbers. Another catch-22....
Just be patient and stick with it. It's WORTH it once you get it idling like stock....
I hope I have been of SOME help....

Dennis

CManT1914 · Sep 14, 2005

Keven, you have the other tools, but still no feeler gauges? You can turn the idle screw until it contacts the throttle blade, then turn it 1 full turn I think (or until it idles 100rpms below your desired idle). Then back the ISC screw out until it idles where you want it. Then do the TPS last. I think I got that all right.

a50sn95 · Sep 14, 2005

BlueOvalStangGT said:
BUMP, I have the tools now, as soon as the car cools down im going to work on it. What should I set first, TPS or Idle screw? How should I set idle if I dont have feeler gauges?

Idle screw first, then TPS. Then if you have to move the idle screw some more to get it to idle, make sure you go back and reset the TPS. I just snugged things enough that they wouldn't move until I was done. Then I went back and made sure every thing was locked down....

BlueOvalStangGT · Sep 14, 2005

Should I set the idle on the tweecer first, then try to match it with the idle screw and then the TPS? Or should I just set the idle and TPS with the stock tune and then start messing with the computer?

BlueOvalStangGT · Sep 14, 2005

CManT1914 said:
Keven, you have the other tools, but still no feeler gauges? You can turn the idle screw until it contacts the throttle blade, then turn it 1 full turn I think (or until it idles 100rpms below your desired idle). Then back the ISC screw out until it idles where you want it. Then do the TPS last. I think I got that all right.

Im over here in college now, away from my tools and my garage. All I have is enough to change a tire and the tools I can borrow from a freind(like a 60 peice walmart set)

final5-0 · Sep 14, 2005

BlueOvalStangGT said:
I dont have access to feeler gauges until I get home(could be for weeks). If im opening the TB a little to set idle, wont that give me faulty TPS readings since the TB blade is open a little already? How am I going to know what to set my idle to if its constantly surging and wont stay still? What has the approximate width of a .1(or was it .01) feeler gauge?

I gotta tell ya, I dont think that tiny bit above 1.0 volts is hurting a thing as I have seen peeps dlogs that was a bit higher but they reported no idle issues.

It won't hurt to knock it down a bit that is for sure.

I got an idea that could help and will share it later tonight but I first got to do a little research and get my stuff together.

Grady

a50sn95 · Sep 14, 2005

I went out and made a recording. This is from a cold start. You can hear how long before I blipped the throttle. I didn't touch the gas pedal until then....
Right click and save as...

My idle SUCKS! What can I do??

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