EFI for my 1979 Cobra

myles

New Member
Mar 14, 2004
15
0
2
51
Illinois
www.mylesworld.com
I have a 1979 Cobra and a 1997 explorer 302 engine with all the stuff on it. I would like to put it in with the painless wiring harness. I have some misc 87+ mustang EFI parts about but I need to know what parts will be needed. I have a gas tank from a donor 87 lx 5.0, I also have a left over throttle body from my 95 Cobra. The painless kit tells me I need the Ford Motorsports comp, but I think I can get a MAF ECU from a later year mustang? I am also using a T5 trans if that matters. Are the injectors on the explorer 302 going to be an issue? I am trying to do this on a buget with junkyard parts when possible. But I also know that it is smarter to buy the right stuff in the first place, so I don't mind being given suggestions on parts I should just buy and not mess around with old stuff. I know there is some post in mags and forums so that info is appreciated also. I also know for some reason the 1979-1980 mustang gas tank is unique and am curious if this 87 lx 5.0 tank will bolt in or not.
Thanks
Myles
 
  • Sponsors(?)


jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,404
2,851
234
74
Dublin GA
lowendmac.com
The Explorer 19 Lb injectors will be just fine, they are supposed to be better than the stock 5.0 Mustang injectors.

List of computers that will work without modification:
A9L - 89-93 5.0L Mustang 5-spd
A3M - 93 5.0L Mustang 5-spd
A3M1 - 93 5.0L Mustang 5-spd
A9P - 89-93 5.0L Mustang Auto
A9S - 88-93 5.0L Mustang California
C3W - 89-93 5.0L Mustang Auto

You may want to use the Ford Racing M-12071-A50 harness. It is one piece from computer to injectors and has all the connections for ignition, MAF, and sensors.

Websites you should bookmark:
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring Mustang FAQ - Engine Information Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for94-95 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/94-95_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

AutoZone wiring diagrams

For 79-88 model Mustangs
http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528004e28c

For 89-93 model Mustangs
http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c15280069677

For 94-98 model Mustangs
http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152801f5e3b

For 1999-2005 model Mustangs
http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152801ef7d7

http://www.fordracingparts.com/home.asp
Download the catalog. You will need the Adobe Acrobat viewer which is also a free download – Adobe - Adobe Reader download - All versions
 

93 LX

Founding Member
Jun 2, 2000
3,081
2
0
Norwalk, CA.
Visit site
jrichker,

If you use the FORD wiring harness will changes need to be made to it as doing it from SD to MAF, since this is what I will be doing when pull the engine on my 86.
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,404
2,851
234
74
Dublin GA
lowendmac.com
jrichker,

If you use the FORD wiring harness will changes need to be made to it as doing it from SD to MAF, since this is what I will be doing when pull the engine on my 86.
Ford Racing's notes on the harness say that it uses a 89-93 Mustang computer. That means it is a Mass Air system.
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,404
2,851
234
74
Dublin GA
lowendmac.com
Yes I know, I was talking about doing the MAF conversion with this harness. Is this a way to go instead of modifing the old harness?
Not unless you have major $$$. The $30 for a conversion kit is a lot cheaper than a $450 harness.
 

myles

New Member
Mar 14, 2004
15
0
2
51
Illinois
www.mylesworld.com
How about this? I have a 87 LX 5.0 donor car in my yard. Would it make sense to convert it to MAF and use it's harness on my explorer eng and 79 cobra? I am not super smart with wires but may be able to figure it out if there was some tech on it out there.
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,404
2,851
234
74
Dublin GA
lowendmac.com
How about this? I have a 87 LX 5.0 donor car in my yard. Would it make sense to convert it to MAF and use it's harness on my explorer eng and 79 cobra? I am not super smart with wires but may be able to figure it out if there was some tech on it out there.
MASS air conversion instructions from MAF - Mustang Mass Air Conversion - StangNet - The Mustang Network FREE
A9L (5 Speed) computer from junkyard $100-$150
A9P (Auto or in a pinch, 5 Speed) computer from junkyard $100-$150
70MM MAF from 94-95 Mustang GT - $40-$70
MASS Air wiring harness kit $30-$85

The whole thing is probably less than $300 using junkyard parts.

The conversion harness seems to work well for most folks. It avoids the compatibility problems in using a harness from the junkyard. Simple and cheap, it is actually less work that swapping the wiring harness. I have pulled the stock harness out of a wrecked car and it was like wrestling a big python.

Conversion Harness kits & parts
Interactive Systems & Technologies Mass Air Home Page
Ford Fuel Injection EFI Harness Pigtails

Larger MAF to go with Mass Air conversion:
94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

*1.) Metal flange adapter Kurtz Kustomz Motorsports, Inc. KKM Buy the TR70 for $44.95. Or spend some time on eBay looking for one that may fit.
Try AutoZone and ask for 81413 - Spectre / 3 in. Aluminum Intake Mass Air Flow Sensor Adapter at $12.00. You may have to order it online.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.
 

1stanger1

Member
Jul 3, 2005
172
1
17
41
in my house
everything is pretty much self explanitory all you gotta do is use a harness from a fuelie 5 liter and sounds like you got all the bolt on parts but as far as an ecu like jrichker said an A9L is your best bet but i think you'll find that they are a little more than that unless your dealing at a salvage yard that doesnt know squat about cores like i do i know that a junk one is $100 at least thats what i pay for them with a good case

there are alot of years you can get these ecm's from you could even go with a 95 ecm i heard it has a slightly higher rev limiter at least thats what i am told but
so far everything sounds right on par.....
let us know how it goes and we'll be here to guide you along your journey! have fun
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,404
2,851
234
74
Dublin GA
lowendmac.com
there are alot of years you can get these ecm's from you could even go with a 95 ecm i heard it has a slightly higher rev limiter at least thats what i am told but
so far everything sounds right on par.....
let us know how it goes and we'll be here to guide you along your journey! have fun

The 95 computer is a different animal and will only work with a 94-95 Mustang harness. The tune on the 94-95 computer isn't as user friendly as the 89-93 models.
 

myles

New Member
Mar 14, 2004
15
0
2
51
Illinois
www.mylesworld.com
Bit of an update. I have a A9M comp from a 90 and all the harnesses from a 90 5.0 with some sensors coming to me from a friend. I will attempt to figure this out, but if it gets to be to much, and it prob will. I will just buy the ford motorsports harness. I have the efi tank and the whole wiring harness from the donor 87 lx 5.0 so I have some parts. I also kept all the fuel lines too.
thanks for all the info everyone

Myles


my garage MYLES' WORLD
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,404
2,851
234
74
Dublin GA
lowendmac.com
Bit of an update. I have a A9M comp from a 90 and all the harnesses from a 90 5.0 with some sensors coming to me from a friend. I will attempt to figure this out, but if it gets to be to much, and it prob will. I will just buy the ford motorsports harness. I have the efi tank and the whole wiring harness from the donor 87 lx 5.0 so I have some parts. I also kept all the fuel lines too.
thanks for all the info everyone
Myles
The computer is OK, but the 90 computer harness is a bit of an oddball item. The harness has dual dash connectors and wiring for the airbags which tend to confuse things. You probably can make it work, but several of the connectors will need to have pins moved around to make it plug compatible with the dash and body harness.

I don't have any details of what needs to be done, so someone else will have to assist you on using the 90 computer harness.
 

myles

New Member
Mar 14, 2004
15
0
2
51
Illinois
www.mylesworld.com
If I have to much trouble with it (and I'm sure I will) Can I just suck it up and get the M-12071-C302 harness? I think it's around 200 bux. I already have the injector harness.
thanks
Myles
 
Thread starter Similar threads Forum Replies Date
MikeR351w EFI to Carb Distributor Shaft length question... Fox 5.0 Mustang Tech 0
C 5.0 EFI swap and weak spark Fox Engine Swaparoo 1
J EFI 351 Swap? 1965 - 1973 Classic Mustangs -General/Talk- 4
S Engine 92 5.0 Carb to EFI Fox 5.0 Mustang Tech 4
7991LXnSHO Want to put EFI on a 6 Cyl. What System to get? Digital Self-tuning Forum 5
Old Catman EFI and megasquirt questions 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 14
Saine65 Best Efi Route 1965 - 1973 Classic Mustangs -General/Talk- 7
JimmyJamTheHamSlam Part Suggestions 1996 / 1998 4.6L DOHC Mashup Engine Rebuild SVT Tech Forum 0
88LX5.Oh Digital Tuning Holley EFI vs factory EEC Fox 5.0 Mustang Tech 33
Ultra90GT For Sale The Nitrous Works TNW efi plate Engine and Power Adder 3
N Advice on EFI tuning solution on a tiny budget Digital Self-tuning Forum 5
F Electrical Does EFI computer case need to grounded? Fox 5.0 Mustang Tech 22
F No fire on a 1987 5.0 EFI Fox Engine Swaparoo 1
M What intake is best for me? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 22
H Holley EFI High Altitude MAP scaling? Digital Self-tuning Forum 7
A Holley Terminator X Max (EFI and Transmission Controller) 1965 - 1973 Classic Mustangs -General/Talk- 3
S Fuel 1995 stock Mustang EFI vs aftermarket TBI or Edelbrock injection? Jag Project Car Fox 5.0 Mustang Tech 13
C Efi to carb fuel wiring help Fox 5.0 Mustang Tech 2
M 1985 Gt EFI/Turbo Help Fox 5.0 Mustang Tech 2
M In Tank Pump for 1966 EFI Conversion-1973 tank? Classic Mustang Specific Tech 2
P Purplefords 67 Mustang EFI T-5 1965 - 1973 Classic Mustangs -General/Talk- 9
Noobz347 Came Across This: Holley Efi Terminator X for your Fox Body Mustang Digital Self-tuning Forum 28
ndfox92 Fox does anyone have a victor efi intake for a 351w they want to part with? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 0
R Carb vs EFI Classic Mustang Specific Tech 0
4u2bnvus WTB/Trade Efi intake Engine and Power Adder 1
Ragtop50 SOLD New Holley HP 550-606 EFI kit with TFI Harness & Knock Sensor ** NEW ** Engine and Power Adder 1
stanglx2002 Megasquirt Digital Dash Digital Self-tuning Forum 45
R Random Question on EFI setup 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 1
G efi help 1965 - 1973 Classic Mustangs -General/Talk- 3
C Factory EFI swap 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 5
S Engine 1989 mustnag efi to holly sniper swap Fox 5.0 Mustang Tech 19
M Fox body 302 carb EFI swap 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 1
Foot Hill Fox What cam? 8-10 psi hci 4:11 gears in my 65 EFI swap 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 13
Foot Hill Engine 65 5.0 efi with Vortech pictures? Fox 5.0 Mustang Tech 0
6 Starter Issues - 68 Stang EFI conversion 1965 - 1973 Classic Mustangs -General/Talk- 5
Barron91lx Fox EFI Distributor Harness 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 1
EdMac67 '67 Coupe, 5.0 HO EFI Swap - Export Brace! 1965 - 1973 Classic Mustangs -General/Talk- 7
S Aftermarket EFI in My '66 Classic Mustang Specific Tech 0
paddyrk Digital Tuning 1991-exhaust crackles Fox 5.0 Mustang Tech 8
jbarker98 For Sale Edelbrock Performer 5.0 EFI Upper/Lower Intake Manifold $300 obo Engine and Power Adder 2
D 351 efi swapping new edge SN95 4.6L Mustang Tech 1
J Efi to carb AC wiring Fox 5.0 Mustang Tech 1
8 Electrical 1988 2.3L EFI to 1992 2.3L EFI engine 2.3L (N/A & Turbo) Tech 2
R 351w with Efi into Foxbody with Efi Question Fox 5.0 Mustang Tech 14
L For Sale 1968 Mustang Coupe - 5.0 with Holley Sniper EFI - Houston, Texas Classic Mustangs For Sale 2
paddyrk Electrical 1991 LX 5.0, radio wiring help, ECU swap Fox 5.0 Mustang Tech 2
R Carb to efi Fox 5.0 Mustang Tech 1
ClevelandTim Engine 86 Capri, Re-EFI? Fox 5.0 Mustang Tech 3
6 67 5.0 EFI The Welcome Wagon 6
moneypit94 Electrical Getting stock tach/speedo to work after holley efi install? Fox 5.0 Mustang Tech 3
Similar threads