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

Fox Misfires Under Hard Acceleration - Carburetor Experts Needed

  • Thread starter Thread starter Demustangs
  • Start date Start date Nov 19, 2017
  • Tags Tags
    fox 89 mustang
Prev
  • 1
  • 2
  • 3
First Prev 3 of 3
D

Demustangs

Member
Apr 7, 2017
79
2
8
Nov 23, 2017
#41
  • Nov 23, 2017
  • #41
jrichker said:
You probably have 2 plugs that are not firing.
Click to expand...

You were right it was bad plugs she runs really good now with .054 gap ngk plugs
 
D

Demustangs

Member
Apr 7, 2017
79
2
8
Nov 23, 2017
#42
  • Nov 23, 2017
  • #42
UPDATE: BAD SPARK PLUGS . I USED NGK PLUGS .054 GAP
 
D

Demustangs

Member
Apr 7, 2017
79
2
8
Nov 23, 2017
#43
  • Nov 23, 2017
  • #43
Thanks everybody for the help along the way I apprciate it!
 
Reactions: General karthief
J

Jack peaker

Member
Sep 26, 2017
6
1
13
Nov 25, 2017
#44
  • Nov 25, 2017
  • #44
Demustangs said:
89 fox body randomly started backfiring and misfiring on hard acceleration timing set at 14 degrees gt40 heads and 650 double pumper on it plugs and everything less than 6 months old only backfires under hard acceleration
Click to expand...
 
D

Demustangs

Member
Apr 7, 2017
79
2
8
Nov 25, 2017
#45
  • Nov 25, 2017
  • #45

Bad plugs. Bought ngk .054 gap fixed it
 
J

Jack peaker

Member
Sep 26, 2017
6
1
13
Nov 25, 2017
#46
  • Nov 25, 2017
  • #46
I see you have it fixed but I was going to say it is a plug or a wire had same trouble before on my 64 1/2 mustang with 302.......
 
D

Demustangs

Member
Apr 7, 2017
79
2
8
Nov 25, 2017
#47
  • Nov 25, 2017
  • #47

Bad plugs. Bought ngk .054 gap fixed it
 
D

Demustangs

Member
Apr 7, 2017
79
2
8
Nov 25, 2017
#48
  • Nov 25, 2017
  • #48
Jack peaker said:
I see you have it fixed but I was going to say it is a plug or a wire had same trouble before on my 64 1/2 mustang with 302.......
Click to expand...

Both actually i flipped the wires over and they had a deteriated crack very small but was still there so definitely had to replace wires and plugs it made the fox very simple and affordable
 
J

Jack peaker

Member
Sep 26, 2017
6
1
13
Nov 25, 2017
#49
  • Nov 25, 2017
  • #49
I see you have it fixed but I was going to say it is a plug or a wire had same trouble before on my 64 1/2 mustang with 302.......
Demustangs said:
Both actually i flipped the wires over and they had a deteriated crack very small but was still there so definitely had to replace wires and plugs it made the fox very simple and affordable
Click to expand...
Very good have a great day...
 
Reactions: Demustangs
Prev
  • 1
  • 2
  • 3
First Prev 3 of 3
You must log in or register to reply here.

Similar threads

9
Engine Donor '00 Mountaineer meet '91 Fox
  • 91firecracker
  • May 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
41
Views
892
Fox 5.0 Mustang Tech May 28, 2026
91firecracker
9
A
Rough idle - cylinder 1 and 6 misfire HELP
  • austindavies935
  • Jul 24, 2025
  • SN95 4.6L Mustang Tech
Replies
12
Views
712
SN95 4.6L Mustang Tech Jul 24, 2025
gkomo
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
SURGING IDLE / NO IDLE CHECKLIST FOR 1996–1998 MUSTANG GT (4.6L 2V) - Work In Progress
  • Noobz347
  • Aug 30, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
732
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
S
Fuel Spits sputter pops and bangs under load. Help wanted
  • sickntired
  • Mar 23, 2024
  • Fox 5.0 Mustang Tech
  • 2
Replies
22
Views
3K
Fox 5.0 Mustang Tech Apr 1, 2024
sickntired
S
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?