Computer swap 1988 into 1987

[Mparsley]

I have a 1987 Ford Ranger 2.9L automatic trans 4x4 and its not a California emission car. My egr tube is broken and I really need to just get rid of egr altogether. I cannot find another tube anywhere. So I have been looking for an '88 computer. When i go to Rock Auto there are 2 computers that seem to fit the bill1) E8TF12A650UA or (2) E8TF12A650UC. Both of the computers are for "88 automatic 4x4 with federal emissions.

Can anyone point me to the correct one? Any advice?

 

[RonD]

Welcome to TRS

The 4x4 part doesn't matter, PCM(engine computer) is not involved with that system

Transmission matters since you have an automatic, in 1987/88 it controlled the 1 solenoid in the A4LD transmission
But double check that your transmission has a TWO wire plug in just in front of the shift linkage
As seen here: https://www.explorerforum.com/forums/index.php?media/a4ld-specification-chart-from-transgo.39537/full

Part numbers
E8TF-12A650-UA
E8TF-12A650-UC

Don't really help, yes they are 1988 parts(E8), but as far as I know the UA or UC won't ID manual or automatic which is the big deal, also engine size

Read here about the STAMPED numbers on the labels that do help: http://www.fuelinjectedford.com/page17.html

Here is one on Ebay: https://www.ebay.com/itm/ECU-PCM-ECM-Engine-Computer-Module-2-9L-Auto-2wd-Federal-Fits-1988-Ranger-20394/333447167529?epid=1981129083&hash=item4da2fffe29:g:7TEAAOSwjJdd~qdd&fits=Year:1988|Model:Ranger|Make:Ford

Says its for 1988 and E8 part number matches that
Also for 2.9l and automatic

 

[Mparsley]

Thanks for the help and lots of info. In the attached pic from rockauto it has a choice of 2 pcm's that say auto, federal Emissions, 2.9L, and 4WD. The only difference is the final two letters UC or UA.

Do you know the difference or does it even matter. If my truck doesn't have the two wire plug in front of the linkage, what does that mean? I will run and check on that today. (I think it does, I think I remember disconecting that when I dropped the tranny and rebuilt it last month).

 

[RonD]

No, Ford never released any info on the revision numbers(UA or UC) or any of the stamped numbers(software)
No cross reference was ever made available as far as I know

E8TF = Year(1988) and T for truck, F for electrical, E9 = 1989, F0 = 1990
12A650 = part number for an engine computer, ALL engine computers, still used today
UA = Revision number, UC would be a later revision

Stamped number was the software engine computer was loaded with(flashed) at the factory when new

From what is said about those 2, either should be fine for your project
Engine size, transmission type, and Federal(no EGR) are the things that matter

 

[Mparsley]

Thanks Ron! Now to break out the piggy bank.

 

[Mparsley]

Here is a pic of the connectiins forward of the linkage on my tranny. What does it mean or what isbthe significance of a 2 wire plug and do i have it?

 

[RonD]

Yes, looks like 2 wires running down into the transmission, just in front of the shifter

The multi wire connector above the shifter is the NSS(neutral safety switch) just FYI, it activates reverse/backup lights and allows starter to work in Park or Neutral


Up to 1988 the A4LD just had one solenoid, so only needed 2 wires, in 1989, a second solenoid was added so it had 3 wires

As shown in previous link: https://www.explorerforum.com/forums/index.php?media/a4ld-specification-chart-from-transgo.39537/full

Lower right corner of image

 

[Mparsley]

I got the computer swapped over tonite along with egr block off and blocking off/capping off manifold egr tube hole. The new computer works great. It hasn't idled this good ever! Also, I don't have any idea why but it shifts way smoother! Also, no huge exhaust leak coming from the egr tube anymore. Pretty simple job except getting the egr/manifold fitting out (that was a little tough) but it is done.

RonD, huge thanks for all your help!

 

[RonD]

Good work

 

[rusty ol ranger]

Good work

I thought the last 2 letters of the ECM number denoted manual or auto trans?

 

[Mparsley]

Rock Auto had 4 separate versions of an 88 automatic computer; 2 with California emissions and 2 with Federal emissions. All I know is that I ordered the -UC version and it is working great.

 

[RonD]

I thought the last 2 letters of the ECM number denoted manual or auto trans?

It might, but I have never seen a cross reference for the "version" numbers, just the Stamped numbers on the PCM label
The EEC-IV was used in all model Fords with EFI, all with different engine sizes and transmission types
Only difference in the "part number" for one year are the 3rd number and the version numbers
E8TF-12A650-UC

3rd number is the model of vehicle, in this case a truck, there is a cross reference for this
Version numbers are a guess, yes could denote transmission type AND engine size, but is hard to say

All 1988 Ford PCMs would have the same other 9 numbers E8xF-12A650-xx

 

[rusty ol ranger]

It might, but I have never seen a cross reference for the "version" numbers, just the Stamped numbers on the PCM label
The EEC-IV was used in all model Fords with EFI, all with different engine sizes and transmission types
Only difference in the "part number" for one year are the 3rd number and the version numbers
E8TF-12A650-UC

3rd number is the model of vehicle, in this case a truck, there is a cross reference for this
Version numbers are a guess, yes could denote transmission type AND engine size, but is hard to say

All 1988 Ford PCMs would have the same other 9 numbers E8xF-12A650-xx

The reason i thought this was because when i ordered a new ECM from o reiley, the kid gave me the wrong one, and the last 2 letters were different then mine. When i plugged in my reader it said something about a missing overdrive solenoid or something, which makes sense as mine is a manual.

It ran it fine, it just idled a bit lower. I took it back and put in the 88 ECM @PetroleumJunkie412 let me have

 

[RonD]

So new PCM was for the same size engine just wrong transmission type, so what denotes engine size, if both version numbers were different

The Stamped numbers seems to be the key: http://www.fuelinjectedford.com/page17.html
And I can see no rhyme or reason to those numbers

 

[rusty ol ranger]

So new PCM was for the same size engine just wrong transmission type, so what denotes engine size, if both version numbers were different

The Stamped numbers seems to be the key: http://www.fuelinjectedford.com/page17.html
And I can see no rhyme or reason to those numbers

Yes, but every single number matched except the last 2 letters. Which is why i assumed they denoted trans.