Idle and the parking brake - Ford Mustang Forum
 
LinkBack Thread Tools
post #1 of 6 (permalink) Old 11-06-2017 Thread Starter
Apprentice
 
FrostySnowstang's Avatar
 
Joined: May 2011
Location: Abilene
Posts: 157
 
Idle and the parking brake

Sorry to beat a dead horse, but I haven't found any cases like mine. My 2003 GT idles high unless the parking brake is set. As soon as I pull it, the idle goes back to normal. I have replaced the IAC, PCV, and TPS already. What does the parking brake have to do with it? Thanks.


2012 GT Premium//Kona Blue, Stone Inter, 6 MT, Electronics Pkg, Comfort Pkg, Security Pkg, Rear Camera, GT 500 A/B, silver stripes, 35% tint, Pioneer speakers, Cervini Type IV hood, J&M Extreme LCA// Arrived 6/13/11
FrostySnowstang is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old 11-06-2017 Thread Starter
Apprentice
 
FrostySnowstang's Avatar
 
Joined: May 2011
Location: Abilene
Posts: 157
 
Oh, it's a manual too.


2012 GT Premium//Kona Blue, Stone Inter, 6 MT, Electronics Pkg, Comfort Pkg, Security Pkg, Rear Camera, GT 500 A/B, silver stripes, 35% tint, Pioneer speakers, Cervini Type IV hood, J&M Extreme LCA// Arrived 6/13/11
FrostySnowstang is offline  
post #3 of 6 (permalink) Old 11-06-2017
PONY Member
4.6L Member
 
stormsedge's Avatar
 
Joined: Oct 2017
Location: E. TN
Posts: 329
 
Quote:
Originally Posted by FrostySnowstang View Post
Oh, it's a manual too.
My recently acquired 2000 GT has similar symptom(s), but I have not taken the time to absolutely eliminate all potential vacuum leaks (fixing the oil blowing pcv helped a lot). Your post prompted me to start looking for what I want to do next with mine, and I found this post by wmburns that I assume you've seen? It is a great resource.

Ford Mustang Forum - View Single Post - Is your mustang stumbling, dieing at idle or idling rough?

I also note that many seem to have had issues with short lived IACs, which I find interesting having owned two long term CVics that were virtually trouble free.

In any event, if I read wmburns' information correctly, ((and apparently I didn't, so I've edited this)) I thought I saw a comment about the drop in idle on the parking brake, but I can't see it now...so we still need to answer your question as to the "why?". I wonder if it is an interface between pcm/abs/traction control that drives the engine to low idle when the rear brake calipers only are compressed? Anyone?

Underestimate me, that will be fun.
GREEN WORM RACING--since 1959

These are my opinions...YOU are responsible for YOUR decisions and YOUR outcomes...AND, my not arguing with you does not indicate agreement with your opinion.
stormsedge is offline  
 
post #4 of 6 (permalink) Old 11-06-2017
SHELBY GT 350 Member
 
wmburns's Avatar
 
Joined: Sep 2010
Location: Houston
Posts: 6,822
         
For the 2004 and older for the parking brake there is no interface between the parking brake and PCM. There is an interface between the normal foot brake and PCM as well as the Speedometer and PCM.

Here's some information on how to trouble shoot IAC/Idle issues:
Ford Mustang Forum - View Single Post - Is your mustang stumbling, dieing at idle or idling rough?

But if you want to truly trouble shoot this issue an ODB2 scanner is likely to make short work of the problem.

Here some information on how to get an affordable ODB2 scanner.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-for...-drop-test.56/

2003 GT Convertible (sold & missed)
2000 GT coupe (Craigslist project. Fixed. Now my DD). Windsor to Romeo swap.

Last edited by wmburns; 11-06-2017 at 02:03 PM.
wmburns is offline  
post #5 of 6 (permalink) Old 11-06-2017
PONY Member
4.6L Member
 
stormsedge's Avatar
 
Joined: Oct 2017
Location: E. TN
Posts: 329
 
Super. Thanks!

Underestimate me, that will be fun.
GREEN WORM RACING--since 1959

These are my opinions...YOU are responsible for YOUR decisions and YOUR outcomes...AND, my not arguing with you does not indicate agreement with your opinion.
stormsedge is offline  
post #6 of 6 (permalink) Old 11-15-2017 Thread Starter
Apprentice
 
FrostySnowstang's Avatar
 
Joined: May 2011
Location: Abilene
Posts: 157
 
I have solved my problem. Turns out I had the hanging rpm issue and the timing of the final drop to normal idle just coincided when I was pulling the parking brake. I restricted the IAC intake tube as mentioned here, https://www.stangnet.com/mustang-for...g-rpms.541046/
and everything runs great now.

2012 GT Premium//Kona Blue, Stone Inter, 6 MT, Electronics Pkg, Comfort Pkg, Security Pkg, Rear Camera, GT 500 A/B, silver stripes, 35% tint, Pioneer speakers, Cervini Type IV hood, J&M Extreme LCA// Arrived 6/13/11
FrostySnowstang is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a VALID email address for yourself, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1