• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

2001 Gt High Idle When Warm

  • Thread starter Thread starter 01gtsilver
  • Start date Start date Sep 6, 2015
0

01gtsilver

New Member
Sep 6, 2015
2
0
1
Sep 6, 2015
#1
  • Sep 6, 2015
  • #1
I have a 2001 mustang gt that is a having a erratic idle only when its warm, I have replaced iac, tps, coil packs, spark plugs, and fuel filter, but nothing has helped. I don't know what to do a this point. Sitting at a redlight it idles at around 800 rpm anf in park it idles almost at 1000 rpm. But when I turn the car off then back on it idles normal until I drive it again.
 
Last edited: Sep 6, 2015

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Sep 6, 2015
#2
  • Sep 6, 2015
  • #2
Based upon your symptoms likely you have an unstable TPS signal. Check out the following post: Note the part about HOW the TPS signal works in a "ratch" function.

Troubleshoot IAC idle problems 1996-2004 | Mustang Forums at StangNet

Note that does NOT necessarily mean that the TPS is bad. How do I know? Because the symptoms change after the motor is turned off. Resetting the motor causes the PCM to re-learn a new ratch value.

What could cause your problem? Some examples include:
  • Loose or noisy TPS.
  • Loose or binding throttle linkage.
  • Throttle body idle stop screw set soooooooo low that the TB linkage is not resting on the stop.
  • Possibly the most important!!! Weak or missing throttle linkage return spring. Note there should be two.
  • After market throttle body installed without correctly setting the TB idle stop screw.
In sort, the TPS value does not matter. What does matter is that the TPS produces the SAME value EACH time the throttle is closed.
 
0

01gtsilver

New Member
Sep 6, 2015
2
0
1
Sep 6, 2015
#3
  • Sep 6, 2015
  • #3
Its a new tps and stock TB
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Sep 7, 2015
#4
  • Sep 7, 2015
  • #4
01gtsilver said:
Its a new tps and stock TB
Click to expand...
I gave you a list of "possibilities" the check. It may be a NEW TPS, but if the the electrical connection is dirty it could create the same result. Just like IF the TPS is loose inside the mounting, this could cause the symptom.

IMO what's most important is for you to have an understanding of HOW the PCM uses the TPS signal to control the idle. This gives the best chance of resolving the problem.
 
You must log in or register to reply here.

Similar threads

S
Mach 1 iac valve in a 4.6 gt
  • solodriverz
  • Jun 3, 2026
  • SN95 4.6L Mustang Tech
Replies
1
Views
44
SN95 4.6L Mustang Tech Jun 5, 2026
squeak93
M
Help! 2003 GT misfire when hot
  • Modular03
  • Feb 10, 2026
  • SN95 4.6L Mustang Tech
Replies
4
Views
334
SN95 4.6L Mustang Tech Feb 13, 2026
Mustang5L5
7
Engine Random hanging idle
  • 706 Saleen
  • Feb 11, 2026
  • Fox 5.0 Mustang Tech
Replies
9
Views
455
Fox 5.0 Mustang Tech Feb 19, 2026
86HO5.0
8
G
Idle surging after warm up
  • GALLY3309
  • Jun 10, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
1
Views
88
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 10, 2026
Noobz347
A
Rough idle - cylinder 1 and 6 misfire HELP
  • austindavies935
  • Jul 24, 2025
  • SN95 4.6L Mustang Tech
Replies
12
Views
656
SN95 4.6L Mustang Tech Jul 24, 2025
gkomo
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?