Blinding flash of obvious???
 

Guys/gals,
I've been fighting an idle problem for months now. Cleaned out IAC and temporarily solved. Put new one on, problem still here. Bought 70mm TB, temporarily solved. New TPS, seemed solved, until this afternoon. HOWEVER, should I have a new EGR for the 70mm TB??? I described everything in order, so..... Advice apprecitated-

Rob

idle problems
 

I'm not sure about the idle problem...but yes, definitely get a matching 70mm EGR spacer. Are you running the stock one right now? That is only 60mm, so you are not getting the full potential out of your T/B. Also, if you are still running the stock intake, honing out the manifold (w/ a dremel or grinding wheel on a drill) where the EGR bolts on will help out the airflow too. Because I'm pretty sure that the manifold opening at the top where the T/B & EGR bolt on, is only 60mm as well.

Okay,
I'm obviously showing off my lack of knowledge here I think. I have the 70mm TB and spacer. But my question lies on the EGR, isn't that the part that sits on the back of the TB spacer, two bolts (12 & 15mm??). Am I barking up the wrong tree with this one? Thanks-
Rob

EGR
 

I may be interpretting(sp?) your post wrong...but you do not have to change to a new EGR (itself) when installing a 70MM T/B & EGR spacer. Just put the old EGR onto the new EGR spacer & plug it in. Am I helping you any here? Let me know if I'm still not on the right track.

I believe he's asking if the egr valve could be causing his idle problems. How old is the egr valve? Have you check for codes to see if the old egr is throwing a code? Also, do you have any other mods to the car becides the TB?

Sorry for taking so long to reply - been busy. Anyway, the only mods under the hood are 70mm TB/Spacer, CAI, & Underdrive pullies. As I stated, the IAC is cleaned out & new TPS. No binding in throttle cable but it still idles high. The check engine light is not on, and I can probably assume the EGR is original (120K miles).

The only thing I can remotely think is:

1) Maybe the computer is bad??
2) I did adjust the butterfly in the TB in an attempt to get it to idle lower- would that make a difference??

I have a love/hate relationship with this thing. It gets possessed randomly (no specific temp or humidity or driving style). About 50% of the time it idles at 2K and won't kick down.

Thanks for your time-
Rob

I worked on a tbird with a similiar problem, idled very high and wouldnt come down. Turned out it was the IAC, the spring went weak and the engine vacuum was sucking it open. It set a code but didnt set the check engine light. Try unplugging the IAC while the car is running if it continues to idles high youve found your problem. Hope this helps.

Lethal,
I disconnected the IAC while the car was idling at 2K, and the idle dropped IMMEDIATELY to around 750rpm. I revved it once, and it dropped to 750 without lagging down. When I reconnected the IAC, it began racing again. So this means the IAC is bad? This puzzles me becuase I bought a new IAC and it didn't solve the problem so I took it back (LOL). Should I go to the store and try another IAC? Thanks,
Rob

What's up you guys and gals? I had the same problem you have. Ford makes an idle air control plate that goes between the t/b and the iac. I don't know the part number off the top of my head though. Go to your closest Ford dealer and ask for it. They should know the number.There was a TSB on it back in the day. Hope this helps. The part isn't more than $15 I think?Good luck!!!!!

Eric

Did this "additional part" you speak of take care of the problem? What blows my mind is that I tried a new IAC and it didn't solve the problem, but that doesn't make sense since it idled lower when I disconnected the IAC.

I think the stang needs a good exorcism. ...

Try this
 

Why did you get a 70mm (you are pushing more than 450 hp right , the stang has a SuperCharger on it right !!) sorry had to vent ;) try this ,has worked on alot of troubled stangs with idle problems ,bookmark it ,or print it
http://66.96.130.106/archives/2002/01/tenpin/

;) hope it helps

let me help ypou out here and get some things straightened out..... first of all u have the egr plugged in right? Second of all you said it idles at 2000rpms right? Did you check voltage at the tps sensor? Should be 5volts on orang wire... if not there take off ur kick panney and back probe pin 26 is there 5v there? If there is you have a broken orange wire..... my guess where it broke is where the tps orange wire comes off and attaches to the egr plug


later

drtbiker- it's a new tps and the egr is connected.
moc- thanks for the 10 pin page, i'll take a look. no superchargers yet... : ) I'll let you all know how it works out tonight... Luckily this possessed beast isn't my only means of transportation or i'd be pissed!

I dont really care if you want to listen or not but i will tell you one more time! You can go around changing everything but it is not going to help if there is no voltage going to the tps! Broken tps wire equals 2000rpm idle. Once again back probe pin 26 if there is voltage at computer then you have a break in the wire. Personally I had the same problem, trust me you learn from experiance and i wasted a lot of time and effort trying to get my idle to go down.

If you wanna listen it is great and i am trying to help you and thats what these forums are for..... I am not trying to start a fight either so take it easy and try it out...

All,
I got home late from work and was unable to disconnect the 10 pin connector. After a few minutes at it I gave up- I need more light than what I have right now to screw with it.

Drtbiker- My intentions were not to be crass or rude. I think the message was misinterpreted. Please explain what "back probe pin 26 if there is voltage at computer" means so I can check it out too. What is the back probe pin 26?

Thanks to all of you who are helping me fight this damn thing. I'm on the verge of lighting it ablaze and calling it a day.

when u open the passanger side door, to your right is the kick pannel take off the kick panel. You will see the computer. You will need a 8mm socket to take the computer off of the inside of the car so it is easier to access the 60pin connector. the attached pic is the plug the wire is orange with i believe a small white line through it. Back probe it and make sure u got volts there if you dont you need a new computer(ecu)

later

here