Car is developing quite the idle issue!!

[Kdubslugga]

First off car was tuned by Anderosn Ford, and for the last 6 or 7 months, the car has idled like a new car. Over the passed few weeks im develping a bad idle problem. When i go out and start it when the motor is cold, it fires right up idles at like 1300 rpm for like 10 sec and then slowly drop to about 850-900 rpm, just like it always did. When it starts to warm up the idle starts hunting around, revving from 950 to 1300 rpm occasioanly worse. It seems to smooth out if i drive the car awhile but if i shut the car down when hot and start it right back up, its horrible goes from like 500 rpm to 1500 rpm for like 30 sec before settling down!! Where would you goes start? Im so sick of idle issues!!!
Car has 2 codes, 29, and 33. 29 is vehicle speed sensor related and 33 is egr no flow detected. I checked for any vacuum leaks and nothing that i can find!

 

[jrichker]

See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.

 

[BYRDPE]

First off car was tuned by Anderosn Ford, and for the last 6 or 7 months, the car has idled like a new car. Over the passed few weeks im develping a bad idle problem. When i go out and start it when the motor is cold, it fires right up idles at like 1300 rpm for like 10 sec and then slowly drop to about 850-900 rpm, just like it always did. When it starts to warm up the idle starts hunting around, revving from 950 to 1300 rpm occasioanly worse. It seems to smooth out if i drive the car awhile but if i shut the car down when hot and start it right back up, its horrible goes from like 500 rpm to 1500 rpm for like 30 sec before settling down!! Where would you goes start? Im so sick of idle issues!!!
Car has 2 codes, 29, and 33. 29 is vehicle speed sensor related and 33 is egr no flow detected. I checked for any vacuum leaks and nothing that i can find!

since it's been fine for the past 6 or 7 months something have to had changed. is idle control off or on? have you tried cleaning the iac?

 

[Kdubslugga]

Alright jrichker, I read through your checklist, found a few ideas to try. I came across 1 guy who had his throttle cable all bunched up and it fixed his. Well unfreakin believable, it worked for me to. I noticed on the PMS when i had the pedal to the floor the TPS reading was only 94%... I thought hmmm thats not right.. I yanked all the vacuum lines out of the way gave the throttle cable linkage 1 big nice arch, instead of 3 or 4 twists and turns that it had. And whadda ya know, it freakin cured it. I have no idea why it was so temperature sensitive, but im not gonna complain!!! Your like the Billy Graham of Stangnet, saving a lot of people a lot of headaches!!! Thanks guys!!!