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

Computer identification..

  • Thread starter Thread starter Codydubb
  • Start date Start date May 5, 2012
  • 1
  • 2
  • 3
Next
1 of 3 Next Last

Codydubb

Member
Nov 3, 2011
149
9
18
Preston, Id
May 5, 2012
#1
  • May 5, 2012
  • #1
curious on how to identify A9L computers and other various fox computers... probably a simple thing but obviously im not literate in that area, or too lazy to pick one up and stare at it..
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,811
234
Dublin GA
May 5, 2012
#2
  • May 5, 2012
  • #2
There is a 1" x 1.5" plastic sticker on the end of the computer opposite the wiring connector.

Computer & interchange information for 5.0 Mustang

Revised 16-Oct-2011 to add O2 sensor harness warnings

The Mass Air computers from 89-93 are interchangeable with a few exceptions. Just be sure you use the MAF & MAF sensor from the same series computer. The auto transmission computers use a different start circuit than the manual computers. You can use an auto trans computer in a 5 speed car with no problems or changes. I have done it in my original 89 Mustang GT, and I know it works OK. I would recommend avoiding using a 5 speed computer in an auto trans car due to the possibility of damaging the computer’ internal signal ground circuitry.

The odd duck is the 93 Cobra computer, labeled X3Z which is internally calibrated for 24 lb injectors. Use the MAF & MAF sensor from the X3Z computer to avoid problems with the computer's internal calibration. Try and avoid the 93 Cobra computer if you can.

Some cautions about O2 Sensor harnesses need to be observed to avoid damage to the computer.
Only run a 5 speed trans O2 harness with an A9L. Do not run an Auto O2 sensor harness with an A9L. Doing so will damage the computer’s internal signal ground.
Only run an Auto trans O2 sensor harness with an A9P in a car that has an Auto trans. Using a 5 speed trans O2 sensor harness with an Auto trans will cause no crank problems.
See http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor- harnesses-manual-auto-differences-year-differences.html for more O2 sensor wiring harness info
If you have a damaged computer with signal ground problems, See http://www.stangnet.com/mustang-forums/749974-computer-issue.html#post7490537 for Joel5.0’s fix to the computer internal signal ground.

All the following are mass air unless they say Speed Density
8LD - MANUAL 88 5.0L Mustang Speed Density
8LF - Auto 88 5.0L Mustang Speed Density
A9L - 89-93 5.0L Mustang 5-spd Mass Air
A3M - 93 5.0L Mustang 5-spd Mass Air
A3M1 - 93 5.0L Mustang 5-spd Mass Air
X3Z - 93 5.0L Cobra 5-spd Mass Air internally calibrated for 24 lb injector
A9P - 89-93 5.0L Mustang Auto Mass Air
A9S - 88-93 5.0L Mustang California Mass Air
C3W - 89-93 5.0L Mustang Auto
DA1 - 87 5.0L Mustang 5-spd Speed Density
J4J1 - 94-95 5.0L SVT Cobra 5-spd
T4M0 - 94-95 5.0L GT Vert 5-spd
U4P0 - 94-95 5.0L GT Auto
W4H0 - 94-95 5.0L GT
ZA0 - 95 Cobra R
D9S - Lincoln LSC
ZXA3
LLX3
CCA1
CCA0
AOL2
AOL3
 
Reactions: 93FoMoCo

Codydubb

Member
Nov 3, 2011
149
9
18
Preston, Id
May 5, 2012
#3
  • May 5, 2012
  • #3
So if mine has been opened up, and i have quite a few mods HCI, the computer may have a tune to it? any way i could tell for sure?
 

LilBerx

Active Member
Jan 11, 2012
340
26
29
Logan, UT
May 28, 2012
#4
  • May 28, 2012
  • #4
What computer is a VM1 out of?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,811
234
Dublin GA
May 28, 2012
#5
  • May 28, 2012
  • #5
LilBerx said:
What computer is a VM1 out of?
Click to expand...
See http://oldfuelinjection.com/?p=17 for your answer...
 
C

Clarkjaren89

New Member
Sep 3, 2015
2
0
1
Sep 5, 2015
#6
  • Sep 5, 2015
  • #6
If i put an a3m1 in my car what maf wouldi need
 
C

Clarkjaren89

New Member
Sep 3, 2015
2
0
1
Sep 5, 2015
#7
  • Sep 5, 2015
  • #7
I have a a9p right now with a 5.0 ho 5 speed
 

mikestang63

SN Certified Technician
Aug 27, 2012
11,606
8,859
214
In the garage
Sep 5, 2015
#8
  • Sep 5, 2015
  • #8
Codydubb said:
So if mine has been opened up, and i have quite a few mods HCI, the computer may have a tune to it? any way i could tell for sure?
Click to expand...

You willl see an aftermarket piggyback chip installed. Normally they are installed onto the port on the back.
 

mikestang63

SN Certified Technician
Aug 27, 2012
11,606
8,859
214
In the garage
Sep 5, 2015
#9
  • Sep 5, 2015
  • #9
Clarkjaren89 said:
If i put an a3m1 in my car what maf wouldi need
Click to expand...
If you have the A9l already, then you do not need to swap out EEC's.
 
D

Dart68

Member
Jun 6, 2016
87
22
18
Jun 7, 2016
#10
  • Jun 7, 2016
  • #10
I kinda have a Frankenstein. My mustang is an 85 with what is supposed to be an 88 motor. The EEC is the VM1 which is correct for the car year. The VM1 is a speed density EEC but if I'm not mistaken it should be for a carbureted engine. Will the EEC work correctly with the 88 SD FI engine? I'm trying to chase down some gremlins.

Thank you.
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,811
234
Dublin GA
Jun 7, 2016
#11
  • Jun 7, 2016
  • #11
The computer type VM1 is for an 86 Speed Density 5 Speed Mustang

See http://www.cb4x4.com/PDFs/Engine - EFI - EEC Program Codes.pdf for more information. You will need the Adobe Reader which is a free download at www.adobe.com
 
Reactions: Dart68
D

Dart68

Member
Jun 6, 2016
87
22
18
Jun 7, 2016
#12
  • Jun 7, 2016
  • #12
jrichker said:
The computer type VM1 is for an 86 Speed Density 5 Speed Mustang

See http://www.cb4x4.com/PDFs/Engine - EFI - EEC Program Codes.pdf for more information. You will need the Adobe Reader which is a free download at www.adobe.com
Click to expand...

Thank you for the reply. So the EEC is correct for the year of the car but one of the owners before me swapped in an 88 H.O. 5.0 EFI engine. Will the VM1 EEC work with the later engine or should I start hunting for the correct EEC?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,811
234
Dublin GA
Jun 7, 2016
#13
  • Jun 7, 2016
  • #13
It should work OK. If you aren't having other problems your current computer should do the job.

To find any other problems that he computer has detected, dump the codes.
Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. I highly suggest that you read it and follow the instructions to dump the codes.
 
D

Dart68

Member
Jun 6, 2016
87
22
18
Jun 7, 2016
#14
  • Jun 7, 2016
  • #14
jrichker said:
It should work OK. If you aren't having other problems your current computer should do the job.

To find any other problems that he computer has detected, dump the codes.
Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. I highly suggest that you read it and follow the instructions to dump the codes.
Click to expand...


Thank you. I've gotten a KOEO code of 67, had to bypass it as you stated for the KOER by grounding pin 30 and then have gotten codes 21, 44, and 94. I know what those codes are and will be trying to remedy them. The biggest gremlin I've got is the car failed an emissions test with very high HC, but NOx and CO were within tolerance. A friend thought that it might be a vacuum leak but if it is it's small as the car has 15" vacuum at idle.
 
B

Bobby from 757

Member
Jun 8, 2018
51
2
8
Newport News
Jun 29, 2018
#15
  • Jun 29, 2018
  • #15
Can anyone tell me what this is out of? It's in my 88 mustang gt 5.0 manual transmission, speed density. Can that be Why its running rich
 

Attachments

  • 20180629_213811.webp
    182.3 KB · Views: 1,058

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,811
234
Dublin GA
Jun 30, 2018
#16
  • Jun 30, 2018
  • #16
Bobby from 757 said:
Can anyone tell me what this is out of? It's in my 88 mustang gt 5.0 manual transmission, speed density. Can that be Why its running rich
Click to expand...
Dump the codes to find out why the car isn't running right.

Dump codes sticky

Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. Codes may be present even if the CEL (Check Engine Light) isn’t on. You don’t need a code reader or scanner – all you need is a paper clip, or if your lady friend has a hair pin, that will do the job.
I highly suggest that you read it and follow the instructions to dump the codes. http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/
 
Last edited: Jun 30, 2018

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,180
17,884
224
Massachusetts
Jun 30, 2018
#17
  • Jun 30, 2018
  • #17
Bobby from 757 said:
Can anyone tell me what this is out of? It's in my 88 mustang gt 5.0 manual transmission, speed density. Can that be Why its running rich
Click to expand...

88-91 crown Vic
 

02 281 GT

Agreed...My wife has great Boobs
15 Year Member
Feb 3, 2009
3,208
1,972
194
Cabot, AR
Jun 30, 2018
#18
  • Jun 30, 2018
  • #18
That computer is programmed to run an engine with the 1-5-4-2-6-3-7-8 firing order. Running that computer on an HO firing order engine will cause all sorts of problems.
 
B

Bobby from 757

Member
Jun 8, 2018
51
2
8
Newport News
Jul 6, 2018
#19
  • Jul 6, 2018
  • #19
jrichker said:
There is a 1" x 1.5" plastic sticker on the end of the computer opposite the wiring connector.

Computer & interchange information for 5.0 Mustang

Revised 16-Oct-2011 to add O2 sensor harness warnings

The Mass Air computers from 89-93 are interchangeable with a few exceptions. Just be sure you use the MAF & MAF sensor from the same series computer. The auto transmission computers use a different start circuit than the manual computers. You can use an auto trans computer in a 5 speed car with no problems or changes. I have done it in my original 89 Mustang GT, and I know it works OK. I would recommend avoiding using a 5 speed computer in an auto trans car due to the possibility of damaging the computer’ internal signal ground circuitry.

The odd duck is the 93 Cobra computer, labeled X3Z which is internally calibrated for 24 lb injectors. Use the MAF & MAF sensor from the X3Z computer to avoid problems with the computer's internal calibration. Try and avoid the 93 Cobra computer if you can.

Some cautions about O2 Sensor harnesses need to be observed to avoid damage to the computer.
Only run a 5 speed trans O2 harness with an A9L. Do not run an Auto O2 sensor harness with an A9L. Doing so will damage the computer’s internal signal ground.
Only run an Auto trans O2 sensor harness with an A9P in a car that has an Auto trans. Using a 5 speed trans O2 sensor harness with an Auto trans will cause no crank problems.
See http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor- harnesses-manual-auto-differences-year-differences.html for more O2 sensor wiring harness info
If you have a damaged computer with signal ground problems, See http://www.stangnet.com/mustang-forums/749974-computer-issue.html#post7490537 for Joel5.0’s fix to the computer internal signal ground.

All the following are mass air unless they say Speed Density
8LD - MANUAL 88 5.0L Mustang Speed Density
8LF - Auto 88 5.0L Mustang Speed Density
A9L - 89-93 5.0L Mustang 5-spd Mass Air
A3M - 93 5.0L Mustang 5-spd Mass Air
A3M1 - 93 5.0L Mustang 5-spd Mass Air
X3Z - 93 5.0L Cobra 5-spd Mass Air internally calibrated for 24 lb injector
A9P - 89-93 5.0L Mustang Auto Mass Air
A9S - 88-93 5.0L Mustang California Mass Air
C3W - 89-93 5.0L Mustang Auto
DA1 - 87 5.0L Mustang 5-spd Speed Density
J4J1 - 94-95 5.0L SVT Cobra 5-spd
T4M0 - 94-95 5.0L GT Vert 5-spd
U4P0 - 94-95 5.0L GT Auto
W4H0 - 94-95 5.0L GT
ZA0 - 95 Cobra R
D9S - Lincoln LSC
ZXA3
LLX3
CCA1
CCA0
AOL2
AOL3
Click to expand...
I have 88 mustang gt 5.0 manual and speed density no MAF. I been running a 9K17 ecm,have a running rich problem. I got a DA1 which is supposed to be in my car and it won't start and run . Can you help?
 
B

Bobby from 757

Member
Jun 8, 2018
51
2
8
Newport News
Jul 6, 2018
#20
  • Jul 6, 2018
  • #20
02 281 GT said:
That computer is programmed to run an engine with the 1-5-4-2-6-3-7-8 firing order. Running that computer on an HO firing order engine will cause all sorts of problems.
Click to expand...
It runs that computer fine besides being rich. I got a DA1 and put it in and it won't run. I checked firing order and timing a few times.
 
  • 1
  • 2
  • 3
Next
1 of 3 Next Last
You must log in or register to reply here.

Similar threads

Engine How to identify EEC-IV
  • keel
  • Aug 17, 2025
  • Fox 5.0 Mustang Tech
Replies
3
Views
311
Fox 5.0 Mustang Tech Sep 1, 2025
Noobz347
Lost my Foxbody
  • Mhalc1
  • Feb 10, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
19
Views
643
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 17, 2026
Mhalc1
Rear Disc and Rims Offsets
  • TripleYellow
  • Nov 11, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
19
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 9, 2026
TripleYellow
A Fox Quest! Find Vanilla Ice's 5oh
  • Noobz347
  • Jul 22, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
20
Views
797
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 18, 2025
FastDriver
new :poo: box, may need to hit you guys up for 79-82 info when i fix thIs turd.
  • rednotch
  • Sep 27, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2 3
Replies
40
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 4, 2026
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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?