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

what would cause a 5.0 to rev uncontrollably?

  • Thread starter Thread starter Asha'man
  • Start date Start date Jul 23, 2004

Asha'man

Founding Member
Feb 5, 2002
1,909
0
0
Denver
Jul 23, 2004
#1
  • Jul 23, 2004
  • #1
On my way home today I saw a blue-on-silver fox GT on the side of the road with his hazards on, so I ducked in in front of him. Was a mexican guy who works at the IHOP by my house, I've seen the car there before; it's really ragged out. Anyway, he said the RPM's just started to skyrocket uncontrollably, so he pulled over. I started it up and it did just that....tached up to about 4k in a second or two and showed no signs of coming down, so I shut it off immediately. Now, being a 2.3 guy with no real experience with 5.0's, what could cause this? Due to the slack on his gas pedal, I'm thinking it was a stuck throttle cable, but I looked around by the TB and didn't see a cable. Anyone ever had this happen? It was an automatic, btw.

Some *******s shouted "hahaaaaa" out their window as they drove past, I don't know which car it was. Guess they thought it was funny to see two Foxes on the side of the road. Flipped them the birdy as an afterthought....let's see another Sunbird or whatever owner pull over next time they're in trouble, shall we....

Ash
 

IndyBlk5.0

New Member
Nov 24, 2003
1,122
1
0
New Whiteland, IN
Jul 23, 2004
#2
  • Jul 23, 2004
  • #2
stuck throttle cable more than likely. The throttle cable is underneigth the throttle body on these cars.
That or a blown intake gasket, which is unlikely.
 

DirtyD916

Active Member
May 25, 2003
804
1
38
Norcal 916
Jul 23, 2004
#3
  • Jul 23, 2004
  • #3
i say throttle cable. find it get some carb cleaner on a rag and just clean it and rub it real good.
 

MustangPunk302

Founding Member
Sep 11, 2002
1,051
0
36
West Michigan
Jul 23, 2004
#4
  • Jul 23, 2004
  • #4
Like they said throttle cable, or a major vaccum/intake leak...
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Jul 23, 2004
#5
  • Jul 23, 2004
  • #5
the cable and linkage for the throttle is under the TB. you can see the cable sheath from the back side of the TB and the linkage from the front.

as said, have him check for a big vac line cracked or that has come off. on a stockish 5.0, vac at idle should be 15-20 inches (if it helps with determining if it is a vac leak).

good luck, and good on ya for helping him out.
 

Asha'man

Founding Member
Feb 5, 2002
1,909
0
0
Denver
Jul 23, 2004
#6
  • Jul 23, 2004
  • #6
Under the TB, got it. I'll see if I can swing by in a day or two when the car's at IHOP and see if he got it fixed and what it was. Thanks guys!

Ash
 
R

riceater89-5.0

New Member
Jun 3, 2004
55
0
0
kentucky
Jul 24, 2004
#7
  • Jul 24, 2004
  • #7
mine was revving up to about 2 or so by itself, i jus unplugged the TPS and left it for a minute, plugged it back up, and wallah!!! but in this case it does sound like throttle cable.
 
T

TheUser

Active Member
Jul 25, 2003
1,859
1
36
Springfield, MO
Jul 24, 2004
#8
  • Jul 24, 2004
  • #8
if not the throttle cable, maybe his tps is off/bad.
 

89MustangGX

I have nothing productive to add!
Jul 3, 2001
10,262
1
0
Mill Creek, WA
Jul 24, 2004
#9
  • Jul 24, 2004
  • #9
I say more than likely it's the IAB on the side of the TB. As they get used they get gunked up with oil/carbon/whatever from the breather and incoming air. You can take it off and clean it out good with carb/brake cleaner and a screwdriver -- try and get it as clean as possible. You may end up having to replace it though if it's really bad.
 
You must log in or register to reply here.

Similar threads

New Member with a 1992
  • Clutchfork
  • Oct 18, 2025
  • The Welcome Wagon
Replies
5
Views
306
The Welcome Wagon Oct 19, 2025
Clutchfork
87 LX 'Vert
  • fun331
  • Jun 15, 2023
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
27
Views
4K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 30, 2024
Mustang5L5
SN Mustang Magnum T56 swap
  • revhead347
  • May 24, 2024
  • 1994 - 1995 Specific Tech
Replies
15
Views
6K
1994 - 1995 Specific Tech Jun 28, 2026
GearHeadGuy
Brakes 1979-1986 Fox Parking Brake Adjustment
  • LiquidStangs
  • Sep 22, 2019
  • Fox 5.0 Mustang Tech
Replies
1
Views
9K
Fox 5.0 Mustang Tech Sep 23, 2019
LX Dave
J
Bringing Her Back To Life
  • James Stratton
  • Sep 17, 2019
  • The Welcome Wagon
Replies
4
Views
1K
The Welcome Wagon Sep 22, 2019
Novajess1972
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?