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

im gona hang myself

  • Thread starter Thread starter 88mustangGT
  • Start date Start date Mar 29, 2004
  • 1
  • 2
Next
1 of 2 Next Last
8

88mustangGT

New Member
Apr 6, 2003
298
0
0
Mar 29, 2004
#1
  • Mar 29, 2004
  • #1
well this is geting really anoying. it all started after i put my lower ported on.

today my rpm would hang at 2500 it would pull the car to that rpm while driving. so i pulled over and moved the trottle body cable thingy to see if it was just stuck but it wasnt. i unhooked my iab and tps and it didnt do any thing so i had to just drive it the rest of the way to school.

what finaly made it stop sticking at 2500 was wot for a few gears.

my idel doesnt drop to 800 till i come to a compleat stop while im movign its at 1100 or so.

what is causeing this? is it the tps or iab or somthing else?

thanks.
 

dastang2

Active Member
Dec 11, 2003
2,020
0
46
tx
Mar 29, 2004
#2
  • Mar 29, 2004
  • #2
tps
 

CobraWannabe

Member
Jul 16, 2003
321
0
17
Lancaster, PA
Mar 29, 2004
#3
  • Mar 29, 2004
  • #3
I think the idle always does that on fuel injected Stangs. Did you disconnect your battery? Maybe the computer needed to relearn everything.
 
8

88mustangGT

New Member
Apr 6, 2003
298
0
0
Mar 29, 2004
#4
  • Mar 29, 2004
  • #4
yup i have tryed adjusting the tps and disconected the battery overnight. i couldnt get the volts high enogh if i remember right the highest i could get it was .7
 
J

jerry beach

Founding Member
May 20, 2002
2,671
0
46
Ocala,FL
Mar 29, 2004
#5
  • Mar 29, 2004
  • #5
Is your engine stock otherwise?

It all started when you put on the ported lower, or after you had driven it for a few miles?

Hook a vacuum guage to it, sounds to me like you have created a vac leak. Did you torque the bolts in sequential steps? check the torque on them again.
 
N

noslow5_0

New Member
Nov 7, 2003
422
0
0
dallas tx.
Mar 29, 2004
#6
  • Mar 29, 2004
  • #6
mine will hang at 1100 while driving, then drop to 750-800 when stopped.... i think thats just how it is....
 
8

88mustangGT

New Member
Apr 6, 2003
298
0
0
Mar 29, 2004
#7
  • Mar 29, 2004
  • #7
ive found all the vacume leacks and i did do the cris cross tightening of the lower.

but it doesnt hang all the time it happens whenever it wants to. thats whats throwing me off.
 

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Mar 29, 2004
#8
  • Mar 29, 2004
  • #8
The idle hanging is normail. When I push in the clutch and am coasting to a stop, it always hangs at about 900 rpms. When I stop, it goes down to 650 or so.
 
8

88mustangGT

New Member
Apr 6, 2003
298
0
0
Mar 29, 2004
#9
  • Mar 29, 2004
  • #9
im talkin like 2k
 
L

L8 MUSL

Active Member
Jan 20, 2003
1,664
0
36
Carlsbad, Ca.
Mar 29, 2004
#10
  • Mar 29, 2004
  • #10
CManT1914 said:
The idle hanging is normail. When I push in the clutch and am coasting to a stop, it always hangs at about 900 rpms. When I stop, it goes down to 650 or so.
Click to expand...

No, it's not.
And, 650rpm is too low.
sounds like TPS is wrong or perhaps you need to clean your IAC.
 

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Mar 29, 2004
#11
  • Mar 29, 2004
  • #11
L8 MUSL said:
No, it's not.
And, 650rpm is too low.
sounds like TPS is wrong or perhaps you need to clean your IAC.
Click to expand...

Then how come everybody else in here has a hanging idle too? I always thought 650 seemed like a low idle, but I checked with Ford and they said it was nothing. 2k is a high rpm for it to hang at, but I'm talking about like 900 or so.
 
L

L8 MUSL

Active Member
Jan 20, 2003
1,664
0
36
Carlsbad, Ca.
Mar 29, 2004
#12
  • Mar 29, 2004
  • #12
CManT1914 said:
Then how come everybody else in here has a hanging idle too? I always thought 650 seemed like a low idle, but I checked with Ford and they said it was nothing. 2k is a high rpm for it to hang at, but I'm talking about like 900 or so.
Click to expand...

By "everybody else in here" I guess you mean everybody in THIS thred.
Mine doesn't "hang".
I set my idle at 900rpm.
 

willys1

Active Member
Dec 2, 2003
1,004
1
36
New Jersey
Mar 29, 2004
#13
  • Mar 29, 2004
  • #13
when mine is warm,and in gear,its at 650
 

ComfortablyNumb

Founding Member
Apr 25, 2002
596
0
0
LB- Jersey Shore
Mar 29, 2004
#14
  • Mar 29, 2004
  • #14
Drill one of the screw holes in the TPS a little larger so you can rotate it more and set it between .97 and .99 Volts. My car used to hang around 2000rpm too and it turned out the intake seals were bad, so you may be leaking air in through an intake gasket or something.
 
I

Idwitheld-1`

New Member
Nov 30, 2003
335
0
0
Portland Oregon
Mar 29, 2004
#15
  • Mar 29, 2004
  • #15
The problem is NOT your tps.

You probably have unmetered air entering the motor.

I had a vac leak in a vac hose under the upper plenum. It was cracked and the idle would swing between 400 and 1500. It all depended on the hose. If I touched the hose, it would jump to 1500, let go and it falls to 400. Damn hose would leak based on vibration and temperature...I swear I set the idle a dozen times but it was all dependent on the condition of the hose.

Pulled a few hairs out on that one. Also, check the PCV hose and make sure its in good.
 
8

88mustangGT

New Member
Apr 6, 2003
298
0
0
Mar 29, 2004
#16
  • Mar 29, 2004
  • #16
ill recheck my hoses, what one was it, the one in the front? cause i would suspect that one for me if its any of them.

when you say leaking air i take it this is between the upper and lower?
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Mar 29, 2004
#17
  • Mar 29, 2004
  • #17
for the record, if not already stated, i believe the stock idle setting was 652 RPM.

as ID said, really check the vac lines under the plenum (upper intake). they really get toasted. you should have 15-20 inches of vac at idle. did you use a new gasket on the plenum to lower intake?

good luck.
 
8

88mustangGT

New Member
Apr 6, 2003
298
0
0
Mar 30, 2004
#18
  • Mar 30, 2004
  • #18
no i didnt, it is the same felpro one that has been on there sense i got the car, the upper has came on and off more times than i could count without a problem.
 
8

88mustangGT

New Member
Apr 6, 2003
298
0
0
Mar 30, 2004
#19
  • Mar 30, 2004
  • #19
ok if there is un metered air geting into the system ie threw a vac leack or seal between upper and lower, that would just cause it hanging at like 1100 before car comes to a stop rigght? i dont see how that would cause it to idel at 2 or 3k and just stick there. if anything it would make the idel more loopy and less smooth.
 
S

sublime29

New Member
Mar 18, 2004
110
0
0
Mar 30, 2004
#20
  • Mar 30, 2004
  • #20
Get some throttle body cleaner and start spraying all areas that could cause a leak.All vacuum lines around upper and lower intakes.I mean every where and listen for a idle chamge and if you hear one that is one of your leaks.
 
  • 1
  • 2
Next
1 of 2 Next Last
You must log in or register to reply here.

Similar threads

7
Engine Random hanging idle
  • 706 Saleen
  • Feb 11, 2026
  • Fox 5.0 Mustang Tech
Replies
9
Views
632
Fox 5.0 Mustang Tech Feb 19, 2026
86HO5.0
8
G
Help! 93 Mustang 2.3L A4LD dies at idle
  • goofyfoot53
  • Nov 17, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
0
Views
142
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 17, 2025
goofyfoot53
G
H
Hanging idle issues
  • HydraX
  • Mar 22, 2025
  • SVT Tech Forum
Replies
5
Views
572
SVT Tech Forum Aug 4, 2025
squeak93
A
Resolved 1989 Mustang bogs down after 3-5 minutes of driving.
  • Alabama
  • Feb 11, 2025
  • Fox 5.0 Mustang Tech
  • 2
Replies
23
Views
1K
Fox 5.0 Mustang Tech May 26, 2025
limp
O
Need a hand: Hanging idle with all new parts
  • Overused03
  • May 15, 2024
  • SN95 4.6L Mustang Tech
Replies
2
Views
1K
SN95 4.6L Mustang Tech May 21, 2024
Overused03
O
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?