I tried all of the idle fix techinques mentioned in similar threads (disconnect iac, adjust set screw...) and my car still won't seem to idle at anything below 1k rpms. I have checked for vac leaks and can't find and obvious ones. I have new everything (iac, o2's..) but could changing from cats to no cats have caused this problem by clogging the o2's?(car seemed to start having problems when this and colder weather happened) Let me know what you guys think...this idle is really starting to get on my nerves. Thanks.
Idle Fix Not Work!
- Thread starter IEatRiceGT
- Start date
Zero Signal
Active Member
Your combo is screaming for a tuning device.
When you say it won't idle below 1k, you mean it stays really high or if you let it too low it dies? I think the problem is that the EEC doesn't realize that there is a lot more air flowing by your Tb than it thinks. And without an accurate MAF transfer, the values the computer us using will be wack.
When you say it won't idle below 1k, you mean it stays really high or if you let it too low it dies? I think the problem is that the EEC doesn't realize that there is a lot more air flowing by your Tb than it thinks. And without an accurate MAF transfer, the values the computer us using will be wack.
The car is a GT and it was tuned by the previous owner using a tweecer r/t module and ran perfectly untill the off road h-pipe install (problems seem to start after that time). It will only idle really high 1k+ and die out on anything below that, though it still surges whenever I start the car. A mustang buddy said it sounds like bad 02's or TPS?
Zero Signal
Active Member
So you DO have a TwEECer then? I hope he didn't tell you he tuned the car and removed the TwEECer or some BS like that 
Yes the tweecer is still in the car and the previous owner tuned the car using it to what seemed like a very good tune prior to selling it to me. I later installed the off road h-pipe and my idle problems soon followed. I don't have time to learn the tweecer software personally, but I am curious to what could have caused my idle problem to all of a sudden arise.
Have you moved the O2's farther down stream?
Do you know how to generate a basic data log? I ask because I would be curious about your af ratio at idle.
You most likely have a lsa such as mine and that can most certainly contribute to an unstable idle?
As you say, something changed when you ditched the cats
You might try a pcm reset
Grady
Do you know how to generate a basic data log? I ask because I would be curious about your af ratio at idle.
You most likely have a lsa such as mine and that can most certainly contribute to an unstable idle?
As you say, something changed when you ditched the cats
You might try a pcm reset
Grady
Methodical
15 Year Member
IEatRiceGT said:
There are 2 ways: 1) you can disconnect the battery for about 10-20 minutes and depress the brakes to kill the residual power and then reconnect or 2) The way I do it and is much easier - load a Al9 or A9l tune in position 4 of the TwEECer and with the key on engine off turn the dial to the No. 4 position. The fan will come on and you will here the fuel pump prime - comuter is now reset.
Now I've seen where some peeps load the Al9 or A9l tune to the 1st position to double as an anti theft device - they remove the switch and as a result the tune in position 1 is the default, I do not recommend this because if the switch is broken, lost etc. the TwEECer defaults to the tune in the 1st position. In this case the car won't run. So Don't Put the tune in the 1st position. Just One Man's Opinion.
Peace
I was thinking you have most likely checked to make sure you did not break any wires or connectors on your O2's or anything like that when you changed pipes.
I was also thinking you most likely have a very low lsa cam spec.
It is a long shot but, the absense of cats should have effected your air flow at idle. If you were on the verge of adaptive limits before you changed the cats, maybe the upgrade was enough to push you over into a territory that starts to cause drivability probs.
I don't know what to say other than check the obvious stuff that may have been disturbed when you changed the pipes
OR
You or someone else can use the Tweecer to find the prob and make the adjustment needed.
I'd like to know what you find out to be the prob
Grady
I was also thinking you most likely have a very low lsa cam spec.
It is a long shot but, the absense of cats should have effected your air flow at idle. If you were on the verge of adaptive limits before you changed the cats, maybe the upgrade was enough to push you over into a territory that starts to cause drivability probs.
I don't know what to say other than check the obvious stuff that may have been disturbed when you changed the pipes
OR
You or someone else can use the Tweecer to find the prob and make the adjustment needed.
I'd like to know what you find out to be the prob
Grady
I have checked eveywhere looking for leaks or broken lines and have seen nothing...I would like to run the tweecer but I am away at college and 1v1 time with the car when I'm home is very limited when you take into consideration the time needed hooking up, loading, learning, and understanding the tweecer software. With the pcm reset using the battery, just unhook it while the car is off and pump the brakes, then rehook? What exactly does that do?
Once the battery is disconnected, the capacitors for the KAM have a residual bit of juice that needs to be dissipated. Creating a draw in the system (brake lights, headlights, etc) drains the capacitors. Now the memory starts fresh.IEatRiceGT said:
If not mentioned, have codes been pulled? You have a TON of variables going on here.
Good luck.
Literally, it's to take the car to AZ and let them do it.IEatRiceGT said:
You can follow the procedure in the repair manual or use one of the many online write-ups (or use a code reader, which includes instructions).
Here is one write-up .
Do note that the test port is on the pass side behind the strut tower on a 5N95.
And if you have a parts house do the codes, make sure they connect to this port and not the OBD-II port inside the car (V6's are OBD-II and your GT is OBD-I).
Good luck.
SeventyMach1
Keep it lubed .... keep it straight .... and keep
HISSIN50 said:
And here is a few more articles that provide a home made how-to & diagnostic codes.http://www.muscularmustangs.com/test1.php
http://www.allfordmustangs.com//Detailed/2006.shtml
http://www.allfordmustangs.com//Detailed/445.shtml
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