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

How hard is it to de-EFI my 1991 LX ?

  • Thread starter Thread starter ExplodingGopher
  • Start date Start date Jun 1, 2005

ExplodingGopher

New Member
Jun 11, 2004
517
0
0
The mistake on the lake (Ohio)
Jun 1, 2005
#1
  • Jun 1, 2005
  • #1
So how hard is it to de-EFI my 1991 LX. A carbed 466 is going in it this month. Do i just pull out that grommet on the passenger side kick panel and yank the wires out, or is there more involved like taking the dash apart (oh god no). I still need to keep headlamp wires etc. because it will be daily driven in the summer. thanks.
 

NosPony

New Member
Apr 2, 2004
278
0
0
Canton, Il
Jun 2, 2005
#2
  • Jun 2, 2005
  • #2
Yea u pretty much have it. Take the harness of the computer and trace it all over the engine compartment and unplug. That is what i did and no issues with lights and such. Also might want to give tall valve covers a look at if u are using them on a BBF. They might rub the brake booster. Friend of mine converted to a manuel brake set up for this reason.
 

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
Arlington, MA
Jun 2, 2005
#3
  • Jun 2, 2005
  • #3
Actually, one of the EFI connectors goes into the chassis harness if my dusty memories of 3 years back serve me correctly. Plus be aware that the AC solenoid has some eec component so that takes some wiring and you'll have about 25 pounds of wire in there (thats a lot) and most of it is now extreneous.

Your best bet IS to pull the dash, cut the harnesses all open and trace wires, keeping only the ones you need. You can reduce the 3 huge looms of wire to a single thin loom. Lemme tell ya, makes tracing wiring faults wicked easy.

Also, the FP relay requires eec input unless you tie the hot and and trigger to key-on. This is if you are still using an electric pump and such.
 

ExplodingGopher

New Member
Jun 11, 2004
517
0
0
The mistake on the lake (Ohio)
Jun 2, 2005
#4
  • Jun 2, 2005
  • #4
I actually just got finished pulling out the main harness from the passenger kick panel. Surpisingly easy. I really dont need anything from the harness anyways, im running all new autogauge gauges, 8,000 rpm tach, GM fuel gauge from autometer, holley black elec. fuel pump hooked up to a switch box, prostreet fuel cell, the whole shebang. Thanks for the info, and i'll keep everyone updated on my progress, the swap should be done late this month or sometime next month.
 

NosPony

New Member
Apr 2, 2004
278
0
0
Canton, Il
Jun 3, 2005
#5
  • Jun 3, 2005
  • #5
The exact same swap u did explodingGopher I just completed it. Fuel cell and the whole nine yards. Any questions just email me at

nospony@sbcglobal.net
 

accidentprone86

New Member
Apr 1, 2005
189
0
0
Westminster Colorado
Jun 3, 2005
#6
  • Jun 3, 2005
  • #6
I would take your wiring harness, computer, and mas air meter of your hand for cheep if ya dont want them lying around.
 
B

Boss 351

Here sthhhhhhhheeeve take a picthh of my man flowe
Jul 13, 2003
2,433
23
48
Canada
Jun 3, 2005
#7
  • Jun 3, 2005
  • #7
Can't wait to see some pics of this beast!
 
You must log in or register to reply here.

Similar threads

0
V6 to V8 Swap info
  • 02_2v_Curtis
  • Jan 11, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
757
1996 - 2004 SN95 Mustang -General/Talk- Jan 11, 2026
02_2v_Curtis
0
Place to Avoid: Jamison Auto Group in Gulfport, MS
  • D Durden
  • Oct 20, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • 2 3
Replies
46
Views
3K
1965 - 1973 Classic Mustangs -General/Talk- Jul 16, 2026
Noobz347
J
Progress Thread Family member 1989 GT- Backstory and updates
  • JRC99
  • Apr 19, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 26, 2025
JRC99
J
Fuel Fuel Pump Rewire, New Fuel Lines, and Installation of New Fuel Pump Hanger with AN6 Connections
  • AeroCoupe
  • Mar 12, 2023
  • Fox 5.0 Mustang Tech
  • 2
Replies
33
Views
13K
Fox 5.0 Mustang Tech Apr 16, 2023
AeroCoupe
B
Help with 1985 5.0 HO EFI Mustang
  • Belliott85
  • Apr 25, 2022
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
3
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 26, 2022
TOOLOW91
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?