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

2000 Gt, Stumble Upon Acceleration Or Low Rpm After Warmup

  • Thread starter Thread starter jayrw
  • Start date Start date Dec 7, 2015

jayrw

Member
Sep 2, 2007
156
0
17
Clovis, California.
Dec 7, 2015
#1
  • Dec 7, 2015
  • #1
Car runs great when its cold but after several minutes of driving it starts to have issues with taking off from a stop, the longer it idles the worse it starts to sound, when I accelerate from a stop it stumbles and hesitates a little until I get into higher rpms, if I rev up the engine a couple times before taking off the symptom is reduced.

Once the car is moving it feels normal power wise even if I get on it.

On the freeway it seems fine but in city driving if I shift into 3rd or 4th to soon, or say for troubleshooting purposes take off in 2nd gear, the car bucks / hesitates like crazy, none of these symptoms occur when its cold.

Not sure what to check, I've had a couple ignition coils go bad before but usually I can tell what it feels like when its running on 7 cylinders vs 8, current symptoms seem different but might be worth noting 6 of the coils are still original (103k miles).

Car is stock.

Any ideas appreciated.
 

BrothersPerformance

Premium Sponsor
Sep 1, 2009
261
11
28
3060 Performance Circle, Deland, FL, 32724
Dec 7, 2015
#2
  • Dec 7, 2015
  • #2
Do you notice if the check engine light flashes while it's stumbling/hesitating? Any CEL at all?

Sounds like coils or spark plugs going bad.
 

jayrw

Member
Sep 2, 2007
156
0
17
Clovis, California.
Dec 7, 2015
#3
  • Dec 7, 2015
  • #3
No check engine light, I was thinking of buying a new coil and swapping out an old coil, test drive it, repeat until hopefully finding a bad one, unless there's an easier way to test them lol.
 

BrothersPerformance

Premium Sponsor
Sep 1, 2009
261
11
28
3060 Performance Circle, Deland, FL, 32724
Dec 7, 2015
#4
  • Dec 7, 2015
  • #4
I would start by pulling the spark plugs and checking them before you start purchasing coils.
 

jayrw

Member
Sep 2, 2007
156
0
17
Clovis, California.
Dec 7, 2015
#5
  • Dec 7, 2015
  • #5
BrothersPerformance said:
I would start by pulling the spark plugs and checking them before you start purchasing coils.
Click to expand...

Ok I did change plugs a few years ago (motorcraft),but guess it's worth checking them out just in case.
 
Last edited: Dec 8, 2015

jayrw

Member
Sep 2, 2007
156
0
17
Clovis, California.
Feb 22, 2016
#6
  • Feb 22, 2016
  • #6
For the sake of completion figured I'd update my post, It ended up being a bad COP in cylinder #4.

I pulled spark plugs and they looked normal (light tan color), Also checked fuel injector ohm readings with multimeter (hardly any variances noted) and finally checked ohms on coil packs (primary & secondary readings).

I did coil readings when motor was cold and again after being hot, the only coil that stood out in any way was coil 4 with a 5.11k secondary cold reading and all other coils read 5.36 - 5.45k ohms (meter set on 20k ohms).

Since #4 had the largest variance I took a chance and swapped it out with a new one (motorcraft), Car has been running great ever since.
 
Last edited: Feb 22, 2016
You must log in or register to reply here.

Similar threads

P
2000 GT Random Power Loss
  • Pinellas50
  • Mar 9, 2026
  • SN95 4.6L Mustang Tech
Replies
4
Views
312
SN95 4.6L Mustang Tech Mar 23, 2026
Pinellas50
P
H
Strange steering/brake issue
  • Haxmaster
  • Jun 2, 2026
  • SN95 4.6L Mustang Tech
Replies
1
Views
94
SN95 4.6L Mustang Tech Jun 3, 2026
squeak93
M
Help! 2003 GT misfire when hot
  • Modular03
  • Feb 10, 2026
  • SN95 4.6L Mustang Tech
Replies
4
Views
403
SN95 4.6L Mustang Tech Feb 13, 2026
Mustang5L5
B
Acceleration Vibration
  • Blown02svt
  • Dec 31, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
13
Views
647
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 5, 2026
General karthief
F
Trouble Shooting Sudden Shift of AFR at low RPM
  • Farva_84
  • Jun 6, 2025
  • SN95 4.6L Mustang Tech
Replies
8
Views
504
SN95 4.6L Mustang Tech Jun 8, 2025
Farva_84
F
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?