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

Mid to High RPM Break-Up

  • Thread starter Thread starter GearHd6
  • Start date Start date May 6, 2006

GearHd6

Member
Jul 19, 2005
459
0
18
Ashford, CT
May 6, 2006
#1
  • May 6, 2006
  • #1
Im getting what feels like an ignition break up starting at about 4000 rpms and up. Has anyone had this happen before? The cap, rotor and plug wires are only about a year old. Does the module on the distributor ever mess up or does that just either work good or totally quit and leave you stranded?
 

DeadLifter

Member
Mar 1, 2006
183
2
19
Portland, IN
May 6, 2006
#2
  • May 6, 2006
  • #2
Check cap and rotor, and fuel pressure. Could be module. Might need to replace valve springs could be floating valves.
 

ALMOSTFINISHED

Member
Jan 8, 2004
315
0
17
Westchester County NY
May 6, 2006
#3
  • May 6, 2006
  • #3
Check around the plug wires, around the primaries of the headers and oil dipstick. I had from how you described-a similar problem. Ended up being the plug boot next to the oil dipstick. It was arcing before getting to the spark plug. You can try going outside at night when its pitch black, unplugging the hood light and starting the car. Make sure the wheels are chocked and the e-brake is on then have someone rev the car thru the rpm range and look for sparks around the plug wires and whatnot. Also if there is any corrosion on the plug boots that could lead you to the problem. Good luck, hope I didn't confuse more than help.

Nick
 

GearHd6

Member
Jul 19, 2005
459
0
18
Ashford, CT
May 6, 2006
#4
  • May 6, 2006
  • #4
ALMOSTFINISHED said:
Check around the plug wires, around the primaries of the headers and oil dipstick. I had from how you described-a similar problem. Ended up being the plug boot next to the oil dipstick. It was arcing before getting to the spark plug. You can try going outside at night when its pitch black, unplugging the hood light and starting the car. Make sure the wheels are chocked and the e-brake is on then have someone rev the car thru the rpm range and look for sparks around the plug wires and whatnot. Also if there is any corrosion on the plug boots that could lead you to the problem. Good luck, hope I didn't confuse more than help.

Nick
Click to expand...

Well I took your advice and went out in the dark and took a look. Everything looks good around the plug boots but it looks like an MSD TFI Blaster coil is to blame. If I rev it up I can see blue light coming from underneath the metal bracket thats attached to the coil itself. Should I just get a new MSD coil or is there something better? The coil was on the car when I got it so I dont really know how old it is.
 

DeadLifter

Member
Mar 1, 2006
183
2
19
Portland, IN
May 7, 2006
#5
  • May 7, 2006
  • #5
What exactly was it doing my car falls on it's face bout 5,500 rpm and starts poppin through the exhaust?
 
G

geo93notch

New Member
Jun 7, 2005
26
0
0
May 7, 2006
#6
  • May 7, 2006
  • #6
My car does the exact same thing at 5300 rpms, I just changed the fuel pump to a 255 lph but it has had no effect, I am thinking about adding an adjustable fuel pressure regulator. I will also check and see if my car is arcing.
 
You must log in or register to reply here.

Similar threads

K
Resolved Weird sound coming from a freshly rebuilt 5.0L
  • karhoot
  • Jun 24, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
199
Fox 5.0 Mustang Tech Jun 27, 2026
Mac131
Engine Misfire below 3K RPM
  • foxbodyclark
  • May 25, 2025
  • Fox 5.0 Mustang Tech
Replies
19
Views
948
Fox 5.0 Mustang Tech May 31, 2025
General karthief
8
Engine Rough idle and aggressive sputtering when accelerating
  • 88vertible
  • Aug 13, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
1K
Fox 5.0 Mustang Tech Dec 13, 2025
Jarhead67
J
J
Engine LOSS OF POWER AT 4,000 RPM.
  • Jarhead67
  • Nov 17, 2024
  • Fox 5.0 Mustang Tech
  • 2
Replies
38
Views
2K
Fox 5.0 Mustang Tech Jan 25, 2025
Jarhead67
J
Drivetrain 83’ Glx convertible C5 Trans help!
  • JacksonJared2113
  • Dec 25, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
393
Fox 5.0 Mustang Tech Dec 26, 2025
JacksonJared2113
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?