Pics of a couple EEC-IV CFI ECMs

[kishy]

A (probably pointless) comparison of the EEC-IV CFI ECMs I've accumulated...

I sure hope the vBulletin img resizing thing is turned on lol.

E4VF-12A650-G1A
EEC-IV CFI-SD
SG
Intel
Removed from 1984 Town Car









E4VF-12A650-G2A
EEC-IV CFI-SD1
SG
Motorola
Removed from 1985(!) Grand Marquis wagon











E53F-12A650-N1B
EEC-IV CFI-SD1
MN
Intel
Removed from 1985 Crown Victoria










D3-E53F-12A650-N1 (there may or may not be a B at the end, the label is damaged)
EEC-IV CFI-SD1
D3MN
Intel
Removed from 1985 Crown Victoria







Some questions:

• What exactly does the "code" (e.g. SG) mean? My observation is that the SG units seem to suffer more than the other two when a defect exists in wiring/ignition.
• What does CFI-SD mean vs CFI-SD1? Is CFI-SD1 a revised version that works out some bugs in the original version of EEC-IV CFI?
• What's the mixture of Intel vs Motorola units out in the wild, and is one thought to be better than the other in some way?

[gadget73]

I have never seen an EEC-IV ECM with the extra card in it before.

The code is the program code. No clue what the various letters mean, or if they have any particular significance but its how Ford identifies one program from another. Unfortunately they were not exactly inclined to share the particulars, but consider you're working with the very earliest EEC-IV stuff there. It came out in 1984, and the first version of anything is usually not very good.

[kishy]

I wonder if that's just a CFI thing and when SEFI came about, they had managed to condense the number of discrete components required. It's funny seeing the differences between even these, which are all functionally equivalent (or should be).

The Motorola unit is of course drastically different. It seems to have a heatsink plate under the PCB which is what those "wings" for the transistors are part of. It's heavier than the others and the case is larger (thicker). Still seem to have an Intel 8061 as do the others, but the whole unit was clearly made by Motorola due to the M logo on the PCB.

[gadget73]

Quite possible. They did change the circuit boards over the years, with the newer ones having more small components for a less "full" look overall. They also look a fair bit different than those computers you have. More driver transistors around the side mostly, one per injector. You've only got 2 injector outputs. Its possible that the truck ECM's look like the CFI ones inside. Those had 8 injectors but only 2 drivers. They ran in a batch fire mode with 4 injectors per driver.

[DerekTheGreat]

Makes me wonder: Were there any programming changes through the years or is an '86 SEFI ECM the same deal as a '91 SEFI ECM?

[kishy]

I can do the same comparison with SEFI ones if I get my hands on a couple...though I figure it's much more likely people have a couple hanging around already as it is.

From my perspective, there is somewhat of a functional goal here...determine, for a given engine management system, which computer is "the best". Obviously with CFI, the best is EEC-IV, but then within EEC-IV there are clearly a handful of variations of the computer so there clearly is a "best" and several "not as goods".

It would stand to reason that "the newest" might be "the best", usually...

[DerekTheGreat]

"Newest is the best," that's what I'm thinking. So with that in mind I should swap in '91 ECM's into our Townies for whatever that's worth.

[Steveh66]

i am surprised to see the sub broad on some of those. Must have added some need input and signal conditioning. Did you have a look at the traces to see what those are for??

[kishy]

i am surprised to see the sub broad on some of those. Must have added some need input and signal conditioning. Did you have a look at the traces to see what those are for??

I lack the "EE" knowledge to understand really what's happening in those circuits so I didn't really study the traces. However if there's one you'd like me to pull the PCBs out of and get pics of the traces, I can do that, just not the D3MN as I think that's the one I'm running right now.

[gadget73]

Check the program code. If its the same code, the year it was made shouldn't have any particular effect. The other thing is what else may have changed. 86 ECM's are different than 88 because of the integrated cruise. No clue if they run better, but the code is not the same and the ECM has at least one extra output to drive the servo, as well as inputs from the buttons.

[DerekTheGreat]

That's what I was wondering about, if the code for the tune was any different/better between years. Where are the program codes located on the ECM? I can start looking at those for funsies next time I'm in a yard. This last time Ashley was not so happy standing around and threw pebbles at me as I pilfered JBL & load leveling suspension goodies from a dead Townie. Can only imagine her enjoyment as I dig for random ECM's that I'm not going to be taking lol.

[GM_Guy]

Keep in mind, that if the computer has been reflashed by the dealer, the subsequent code may or may not be on the ecm. Three character code, on a sticker a hair bigger than an old 5 1/4" floppy write protect sticker. Sticker can be added to the drivers door, or stuck on the pcm, or underhood. Someone else probably has the official recomendations on where to put it.

My '89 Grand Marquis hustled pretty quick. First half 89 build.

Alex.

[kishy]

Derek, the code (e.g. SG, MN, D3MN...) is in varying spots on my ECMs. The large sticker on one of the large flat sides specifies it but depending on which side it's on, it may not be visible in the car. A couple of these have a smaller sticker saying the code on the end of the unit that face inside which you could see while installed.

Alex, are these units reprogrammable? I would expect the use of an EEPROM which might not have the required pins exposed to the 60pin or the card edge connector that 'tune chips' plug into. e.g. I assumed the code was programmed to the chip prior to assembly.

[gadget73]

They can be fiddled with, though you can't actually reprogram the ECM itself easily. That front connector that has the shmoo on it is intended as some sort of factory diagnostic / programming port. There are chips that plug into that, and the ECM will actually run on chip's program instead of whatever is in the internal program. Thats how things like the Quarterhorse and the twEECer work. They aren't compatible with all ECM's though. Not really sure how you'd hard-write the data to the internal EEPROM, but it probably would be done using that port and other equipment that us common folk don't have.

[DerekTheGreat]

OH, so that's how that stuff works.

The codes D3MN and such also denote the tune? I'll keep the dealer sticker thing in mind when looking for other ECM's.

Ashley's '89 was built in September of '88 IIRC. My '88 used to be much faster than her car until she put duals on it, now we're neck at neck for the most part.