Hello and I hope someone can help solve this issue I have.
I got this truck 6 years ago, motor and everything but transmission was worn out, had motor rebuilt and literally replaced everything but the Alternator LOL
Motor ran very weak, had to come off line at 3000+ and feather the clutch and still would buck or die
So after a bit more diagnostic work I found it was the ECM, all other emissions controls IAC, TPS, IGN Module, Distributor, Cond. Coil, Evap Coil, Compressor, PS Pump, 2 of the 3 fuel pumps, rotors, calipers, axles, seals, drums, wheel cylinders, exhaust etc were all DOA leaking, frozen, failing etc..
The Truck had 266K on it, was given to me so I knew what I was getting into here LOL

So I sent ECM to have bench tested and it was bad also, the company that bench tested it rebuilt it and returned it, installed and vroom, truck ran, idled fine but very weak when taking off and accelerating.
So I re-checked timing, wires, dist., module, cap and rotor all new, timing was good, looked for vacuum leaks, none found, check fuel pressure on rail and verified regulator (new also, original was pouring gas past diaphram) was working correctly for fuel pressure, all good.
So I was very perplexed.
Then I found out that this truck has the HO motor in it (A friend told me that was probably the issue) and the ECM had been replaced before so my replacement was, from what I have found, WRONG.
So I call the dealer and get OEM ECM # which is E8TF-12A650-AJ1 / AJ2
The dealer gave me my info from the VIN # 1FTDF15N5KNB61377
and from the Cal. Code # 8-53F-R10
I talked with Cardone 2 years ago (2 hours) and they told me from the OEM ECM # I needed a A1 78-4790, not the A1 78-4688 that was in it that I had tested and rebuilt.
So I took the one I had rebuilt and gave it to O'reilly's as a core and purchased the A1 78-4790.
A1 78-4790 is a E9TF-ARA
A1 78-4688 is a E8TF-AJA, AJB
OEM # E8TF-12A650-AJ1 / AJ2 (From Dealer - OEM ECM #)
*Cardone has no listing/cross reference (this most recent call/Representative) for the OEM AJ1 or AJ2 unless it was a AJ1A or AJ1B which their info said crossed back to 78-4688 which made the motor run like a 4 cyl..

Now, after installing this different ECM, the E9TF-ARA version, the Truck runs wonderful, backed it into the road and took off as I had been doing before and smoked the tire, has great power and torque, no more bucking or hesitating, idles & runs great, also it idles down from a cold start quicker without stalling when rpm drops, other ECM woulf high idle at 2K rpm and when it dropped the motor would miss/hesitate and stall, current ECM high idle 1.5K rpm and drops back sooner and smoother and no hesitation or stalling.

So here is my problem, Cardone says (this time, this Representative) they have no cross reference for the OEM E8TF-12A650-AJ1 or AJ2, they say they do have a cross for the E8TF-12A650-AJ1A or AJ1B.....................BUT it crosses back to the ECM that was making the truck seem like it had a 1.5L 4cyl in it................................

And then when I give them the # for the one that is in it now (E9TF-ARA) it does not cross to my Truck at all, of course this is a different Rep 2 years later so maybe he does not know how to use the software ?????

No one seems to know about this HO 5.0L motor or have any listing for it to discern between the two in regards to the ECM's, but one Rep at Cardone 2 years ago knew and gave me the 78-4790 # as a direct replacement for the OEM #, and then this guy today is just lost in the sauce and real happy to get off the phone even though he could not answer my question.
Not even the Dealer could tell me if there was a way to tell if it had the HO Motor...................I know there is not much HP difference (185/205) but obviously there is a big difference when it comes to the ECM !
I know there is someone out there that can help me, do I have the HO motor ????
Pretty sad the Dealer cannot give me solid answers with all this info, I can understand a parts rebuilder not being able to, and though the ECM is working very good it would seem, it is listed as a "AT" application which should not really matter since I do not believe the '89 AT was electronic anyway.
would just like to know if I have the right one in it as if not, maybe it would run even better still ?????



Can someone please help, I would be forever in your debt, this is the first Ford I have ever owned, and I do like it, it is a beast with a 8' + bed and runs very nice even though I think it would be better with newer computer FI or just go back to a carb, but EPA rules ....................but even though it does run strong and is faithful as any truck I have had, just do not understand why it is so hard to get a straight answer on this ECM issue, it's like no one knows the HO motor exists, and as far as I know it may not be the OE motor, just really confused, Please Help Me
The guy at the dealer told me it was likely a HO motor when I was having the original issues, he saw it in person, but not sure how he found out, and now he is retired and the guy there now has no clue how to tell.
The only fact I have is that the alternative ECM (E9TF-ARA) makes it run like it should or at least normally which is far far better, the other was like I said, like I had a baby 4 cyl under the hood, changed to the different one and wow, it ran like a V-8 was actually under the hood.

Thankyou

Guy

 

You probably won't find an ECM that is for an HO motor for your truck, because I believe that there wasn't one. Later the 5.0 truck motor received a roller cam but it still wasn't an HO motor. The only HO motor I know of that was in an 80s F Series was the carbed 5.8.

I'd say that if your truck has an HO motor in it, then it was swapped from a Mustang at some point.

 

 

From my homework so to speak, not being educated in the FORD arena, says that for these trucks there is a 185hp and a 205hp, the latter I guess being called a HO ?
I have no idea what the firing order is, but I can check easy enough, will check and get back to you on that, this motor does have the roller cam, and maybe that is the HP difference.
The ECM that is in it now allows it to run like it should, and I have been told there was a HO motor, but that the HO was derived from different head design (E9) to my understanding and then also a different ECM which incorporated different Cal. Programming.
Not sure what the different head design entailed, the guy that rebuilt it told me that the different heads to his knowledge were only ported better, not larger valves to his recollection, but he was aware of the motor from his rebuild experience, other reading/homework I have done also indicates no change in valve sizes or cam but just head design and Cal. Programming on ECM.
I mean it is not a drastic difference, just 20 HP.

 

It is not a Model HO, rather a motor option HO from what I have learned, and I do not believe it has been swapped, as soon as this Arctic Air leaves here lol I am going to try and find some castings for heads as the E9 heads from what I have researched are the HO version heads, and maybe with a block/head castings I can verify whether the motor has been swapped but I do not believe so, it was a one owner with 266K miles on it, farm truck, dealer cared for, but the dealer that sold it is no longer in business, I have paperwork on it for maintenance and care from day one including the original purchase stickers and pricing/sales paperwork.

Copied from previous reply:
From my homework so to speak, not being educated in the FORD arena, says that for these trucks there is a 185hp and a 205hp, the latter I guess being called a HO ?
I have no idea what the firing order is, but I can check easy enough, will check and get back to you on that, this motor does have the roller cam, and maybe that is the HP difference.
The ECM that is in it now allows it to run like it should, and I have been told there was a HO motor, but that the HO was derived from different head design (E9) to my understanding and then also a different ECM which incorporated different Cal. Programming.
Not sure what the different head design entailed, the guy that rebuilt it told me that the different heads to his knowledge were only ported better, not larger valves to his recollection, but he was aware of the motor from his rebuild experience, other reading/homework I have done also indicates no change in valve sizes or cam but just head design and Cal. Programming on ECM.
I mean it is not a drastic difference, just 20 HP.

Guy

 

What Ty told you is correct, there is no such a thing as an "HO" 302 in trucks, certainly not in 1989. The only 302 available in the bricknose trucks was the 185hp version.

The 302 was upgraded with the roller cam and mass air in 1994 and that is the 205hp version with the 351W firing order, but it is still not considered an "HO" motor by Ford.

 

Order is 1-5-4-3-6-3-7-8 which agrees with VIN "N" on the plate, checked it on the distributor in truck.
In searching for this info to check I do see that there is a similar year HO but firing order is 1-3-7-2 etc
So still wondering if it is the 185HP version and if it is supposed to have the recommended ECM for that motor then why will it not work correctly ..............
Why then am I using a diff ECM that the motor runs right with that does not cross to this truck per every company I have spoke with.............

 

Yes, mine has a MAP, firing order is consistent with Vin N, if all this is true then why will it not run on the recommended ECM ????
Just want to figure out what is going on here, seems as if I will never get an answer and just will continue to run the ECM that actually works as opposed to what they say it is supposed to have .................

 

Your so-called rebuilt PCM obviously had some issues, hence the reason why the engine appeared to run on 4 cylinders. The computer that was "recommended" by Cardone is listed for a 1990 model year F150 with a 5L engine and an AOD behind it. That's why it will work for your manual transmission truck. I could not find any listing for the correct PCM recommended by Ford, based on the calibration code, so it must be a very specific model year/emission programming that has very little, if any, aftermarket support.

You are getting everything out of that factory 185 HP 5L engine right now as far a fuel injection programming. Even if you went to aftermarket you will not gain much. The heads and tiny cam are really holding back the airflow.

 

I agree with rla2005, while the ECU you have may not be the exact same as the one that came from Ford, it runs good and is close enough for your purposes. Move on to next issue.

 

The one they gave me at the Parts Store, the 78-4688 (E8TF) was what they said it took, that is the one that ran like a 4 cyl., as well as the one I had rebuilt which was a 78-4688 also, both ECM's were fine but the motor was not running on them.
Then I give the Cardone guy 2 years ago the OEM ECM # and he crossed it to the 78-4790 (E9TF), which the last one I spoke with at Cardone was unable to do and could not understand LOL, but, I put the 78-4790 (E9TF) in it and it runs as it should.
So I remain confused as hell as to why I cannot figure this out or better yet get a straight answer regarding part and application, there has to be a good answer for all this right ????? LOL
I assumed like you said that the AT issue would not matter since they were not electronic anyway to my knowledge, that is part of my problem, this is the first FORD I have ever owned so I am really lacking in the knowledge of models, engines etc..
I just feel there has to be a reason why my model/year is taking me to the wrong ECM, but I will keep searching for an answer, and in the meantime I will just run this ECM and be happy I guess, I would just like to know why, maybe it is like my 95 GMC Jimmy that has several '96 parts on it that auto parts people have argued with me over until I took the part off and showed it to them, maybe it is just that .....................
I also wanted to know if it was a option HO motor which you guys seem to be pretty sure it is not, and I accept that from you all, just wonder why the OEM ECM # will not cross with anything with these people ???
If the ECM ever goes bad again, I will see if I can get the same one except with a MT designation, as you said, I do not think that is a issue but if they have one at least it will be the right match for the actual truck
I have looked into with people maybe putting a mild cam in this truck with some GT heads, but they are all telling me it will not work out well with the current EFI and MAP, so I have decided to let that go, they say I can do that but would need to replace EFI and have it tuned, and I do not really want to get into all that money, if it were cam and heads, I could do that, but I do not want to open a can of worms.

Guy

 

The computer that came with the trucks part number was E8TZ 12A 650-AJB.

Here is the parts list for that calibration number:


/

 

Any idea why the "right" one would not work, that is my issue, call it trivial as some seem to imply but the Dealer has on there software / system a E8TF12A650 AJ1/AJ2 (AJ1 or AJ2) which crosses to nothing per like 5 different rebuilders and many many searches I have done, but yet, what your pic implies is the same as the retailers and rebuilders say for the VIN which is different from what the dealer is telling me, yet Cardone 2 years ago quoted me the E9TF for the proper ECM which by the way runs beautifully, perfectly.
I know I am kinda beating a dead horse, I got one that works and I should move on, but why, there should be an answer somewhere for this ............right ????

The E8TZ would not run the motor correctly, far from correctly, hesitating, bucking, powerless off the line, powerless acceleration, and high idle was 2K rpm and would stall and cut off nearly every time it came off high idle, in my opinion must have been running very lean or a timing issue maybe, this was confirmed by not one ECM, but two, one reworked and programmed (mailed off for bench test and repair / reprogramming) and one purchased reworked fromm O'reilly's (Cardone also) , both of those were the E8TZ, and both presented the exact same motor behaviors, but the Dealer OEM # per the VIN was a E8TF, and then the one that crossed to that by Cardone by one Rep that obviously knew how to use the software tells me it crosses to a E9TF, put the E9TF in and the motor runs flawlessly.

So it is possible I should be using a E8TF ????? Would that be the same as the E9TF for the most part ???? The only issue with the E9TF is it is originally intended for a AT, but like previous replies and what I kinda figured, since the AT for that year was not electronic I guess it is not an issue so to speak.

Finally, Thank you for replying to my message I sent you and again to this post, I greatly appreciate it.
If you can give me any sort of explanation for all of the above I would so very much appreciate it, just want to make sense of all this conflicting info, and results regarding the ECM
I am also worried regarding the ECM about error reporting functions, just not sure how all this works out especially since this seems to be a ghost I am chasing between aftermarket info versus dealer info, at least it is just in regards to the ECM, everything I have personally done regarding parts seems to be correct, axles, bearings and seals, wheel cylinders, drums and shoes, rotors, bearings, seals, calipers and pads, exhaust, sensors, distributor, wires, plugs, serpentine belt, accumulator, evap coil and condensing coil, compressor, A/C hoses and metering devices,radiator and hoses, Air pump and check valve, EGR and related sensors, FP Regulator, TPS, IAC.................. I have personally done all of this and every part has been right except the ECM, and yes it needed each one too, LOL
This truck was given to me, and I think it sat in a barn somewhere for many years after it was just all worn out, I think most of the many failures were from sitting but then it did have 266K on the motor, and the guy that rebuilt the motor for me said it definitely had that mileage, he said the crank bearings were as thin as paper, when I drove it to him, it was only producing 1.5 psi oil pressure @ 70mph LOL, I put a analog pressure gauge on it piggybacked from the oil pressure sending unit to verify the oil pressure for trouble shooting purposes since this year has a idiot light type oil pressure sending unit driving the oil pressure gauge on the dashboard
But motor rebuild included I got close to $7K in it, and it is very faithful for the past 6 years, just would like to iron out this ghost ECM

Guy

 

To begin with the numbers like E8TF and E9TF are not Ford part numbers.
All Ford part numbers for those years should have the "Z" in them.
The numbers with the "F" in them that are on the part are engineering or drawing number.
Ford does not put a part number on any part after about 1955.
The reason for this is that Ford changes the part number from time to time.
The Ford dealers should be able to cross an engineering or drawing number to a Ford part number.
The number I listed above was the Ford part number for the EEC Computer at the time the truck was made.

 

Ok, well the dealer is the one that gave me this Part or Code # E8TF12A650 AJ1/AJ2 (AJ1 or AJ2) for the ECM that is supposed to be in the car per the VIN and the Cal. Code and it would seem that would be good enough to research a proper replacement Part # in the retail world, but I guess not.
I do know if you look up the Cardone 78-4688 it will tell you it is for a E8TZ and if you look up the Cardone 78-4790 it will reference the E9TF, so one would think that the number they gave me would be able to be worked with reference wise for a actual part #, better yet the correct one LOL.

I also checked the number on your pic you linked me and it crosses back to the same Cardone 78-4688 which clearly per the engine operation is not the right one, so the saga continues, of course this has been the issue from square one, obviously there is a mix up somewhere.
I am going to pull block and head castings to see if maybe the motor was swapped, but I am fairly sure it was not, I have the complete maintenance history on this vehicle from the day it was purchased.

Reference Cardone listing the "F" as a Part #, this is why I figured it was :
Replaces Original (OE) Part #:
E8TF-AJA, E8TF-AJB

I will do as you suggested and contact the dealership again, and ask them about a actual part # regarding the above # they gave me, maybe that will work, if not I will go as high on the FORD Tech Support ladder as I can for an answer.
Thankyou for the help and for responding, it is very much appreciated

Guy