• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

crazy idle issues

  • Thread starter Thread starter 89FoxBodyStang
  • Start date Start date Apr 25, 2012

89FoxBodyStang

Member
Jan 15, 2010
45
1
8
A small town in Michigan called Marysville
Apr 25, 2012
#1
  • Apr 25, 2012
  • #1
hey guys i just started noticing my idle changes when my car gets warm... it will stay at like 1200 rpms after driving it for a bit, but then it seems to go back down again, but when its down it kinda seems like its hunting for idle. it will go up and down. i installed a steeda seperator and i think that may be the problem, becuase when i started moving it around i noticed the idle kind of even out. but this thing seems to be catching a good amount of oil so i want to kinda keep it on. but i have it wedged on my AC hose to hold it up since its not mounted anywhere. just seems ike somewhere around that area is a vac leak. bought a PCV valve was thinking about getting the grommet too... let me know what you guys think. also there's no real difference in the way it idles with the IAC motor unplugged when its hunting.
 

Three50won

10 Year Member
Jul 11, 2010
1,135
64
69
Apr 25, 2012
#2
  • Apr 25, 2012
  • #2
First I'd say fix the vacuum issues. Otherwise you're never gonna solve the idle problem. Second I'd say get the Steeda separator mounted correctly and fix whatever the problem with it is that makes the idle change when you move it around. AFter those issues then I'd look at the IAC. If it still does not change idle quality when you unplug it then you may need to buy a new one.
 

89FoxBodyStang

Member
Jan 15, 2010
45
1
8
A small town in Michigan called Marysville
Apr 25, 2012
#3
  • Apr 25, 2012
  • #3
should i try eliminating the seperator from the system to see what changes that makes? and also, the vaccum gets pulled from the lower intake right? or is vaccum pulled from the valve cover?
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Apr 26, 2012
#4
  • Apr 26, 2012
  • #4
I would bypass the separator (for now - for testing) if this occurred after plumbing it in.
 
Reactions: 89FoxBodyStang
You must log in or register to reply here.

Similar threads

F
Engine 1988 Foxbody idle issues
  • fernandosgarage55
  • Apr 28, 2026
  • Fox 5.0 Mustang Tech
  • 2
Replies
26
Views
636
Fox 5.0 Mustang Tech Apr 30, 2026
AeroCoupe
C
Engine Idle cuts out
  • claypoolxx
  • Mar 7, 2026
  • Fox 5.0 Mustang Tech
  • 2
Replies
25
Views
798
Fox 5.0 Mustang Tech Jul 24, 2026
alutwon
7
Engine Random hanging idle
  • 706 Saleen
  • Feb 11, 2026
  • Fox 5.0 Mustang Tech
Replies
9
Views
672
Fox 5.0 Mustang Tech Feb 19, 2026
86HO5.0
8
B
Engine Strange Noise
  • burntokita
  • May 8, 2026
  • Fox 5.0 Mustang Tech
Replies
8
Views
410
Fox 5.0 Mustang Tech May 11, 2026
keel
G
Idle surging after warm up
  • GALLY3309
  • Jun 10, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
1
Views
138
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 10, 2026
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 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?