Fi Ecu Mods And Differences?

[wheee!]

So I have three FI ECU's.

All of them are A11-600-000 but different lots. How do I know if they are the same or if they are for different model (year) 280's?

Pics of the two that are out of the car at the moment.

Logic board says A12-001 003 6cyl  This one is from Lot 6825



 

 

This one is C12-001 004 N  This one is from Lot 7Z07



Does anyone have experience modding these boards or even identifying them?

Thanks for any help!


Sent from my iPizzle ringy dingy device....

Edited March 3, 2015 by wheee!

[Zed Head]

So I have three FI ECU's.

All of them are A11-600-000 but different lots. How do I know if they are the same or if they are for different model (year) 280's?

 

Does anyone have experience modding these boards or even identifying them?

 

The A11 number tells the application.  There are many other A11 numbers.  Your three should all work the same.

 

superlen has expertise, as well as Captain Obvious (I think).  superlen is/was developing an ECU replacement, more modern and tunable.

Edited March 3, 2015 by Zed Head

[wheee!]

I have been patiently waiting for superlen to update that thread.... I think the Hellfire sounds great!

 

I am just concerned over the vast differences in circuit board design between the two ECU's. Similar pinouts, but different resistors, transistors etc. whole sections of the cb are different... I was concerned I had an ECU for a model that did not control the fuel pump relay....

[Zed Head]

That is interesting,  They build to specs. though, maybe the component quality just got better.  I have several of those, if I have a later lot number than the first one, I'll open it up and see what's in there.  Maybe there's a certain break-point number to look for, to get more modern parts (designed 39 years ago instead of 40).

 

The ECU doesn't control the fuel pump relay, the AFM switch does.  Although I think there are some diagrams out there that show some interaction with some ECU pins.  But there are also errors in the early ECU wiring diagrams.  Pins that don't exist.

 

Somewhere out there is a list of what the various resistors and capacitors do.  But the work needed to make changes is difficult.  Easier to just add a potentiometer to the coolant temp. circuit.  Change the inputs, not the ECU parts.

[wheee!]

I think I remember reading about the potentiometer on the coolant temp circuit somewhere, but I was under the impression it required a lot of constant adjusting to keep it dialled in through the rpm range etc....

 

I am going to use the most modern of the three ECU's, just for component reliability sake. It would be nice to replace them with the Hellfire for tune-ability and future expansion though....

[Zed Head]

Here's Lot #8107.  No clues here.  I don't think I've seen any with the shiny new parts yours shows.  They all have the circular heat sinks.  Maybe yours is a rebuilt unit.

[Zed Head]

All three of these are different, but all three have some similarities.  Look at what looks like a screw terminal at the top.  Mine and your "modern" unit have the same number of filled spots.  Your older one has many more.  But mine and your old one have the same heat sink parts (I don't know my parts...).  And the circuit boards themselves are all three different.  Edit - actually the later lots, mine and yours, have similar circuit boards.  But different parts filling the holes.

 

Probably made at various subcontractors to some performance spec.  Maybe.

Edited March 4, 2015 by Zed Head

[wheee!]

SO very strange indeed. The resistors and capacitors loaded into that terminal bus in white really confuse me. Overkill in one case for sure as they probably only use the 4 like the other boards...

[Captain Obvious]

The (C12-001 004 N) ECU with the larger rectangular multi-legged components is newer than the other one you have pictured. I wonder if it's aftermarket or a newer factory replacement. If it were me, I'd use the newest one you got that runs properly.

 

The pics aren't clear enough for me to pick up any date codes, but it's likely that you could be able to closely estimate the dates of production by determining the manufacturing date of some of the parts used on the boards.

 

Also, it's academic, but...

 

The components loaded into that white holder are not resistors They're actually inductors. They use a L-C (inductor and capacitor) as a filter to try to prevent high frequency interference from entering the ECU circuitry. Each pair of little L's and C's is a filter on a pin that enters the case. I bet they decided that some of them were no longer necessary as time went on. Better filtering elsewhere in the car maybe?

 

I wouldn't call the more heavily loaded filter section "overkill". Noise is a tough and difficult to pin down opponent. And sometimes when the schedule is looming there comes a time where sprinkling some insurance in the form of some cheap components is the right course of action.

 

[wheee!]

Excellent suggestions and info Captain! Thank you!

[Captain Obvious]

Glad to help.

 

Forgot to ask before, but to double check... What you were originally saying is that you've got three ECU's in your possession and all three of them outwardly appear to be identical. Same part number on the outside of the case and all three "should" work fine in your 76. But you took the case off and found significant differences inside (at least between two of them). And you're wondering "What the heck? I thought all three of these were supposed to be the same?"

 

Did I get that right?

 

I'm intrigued by the ECU you have there that has DIP (Dual Inline Package) components instead of the round ones with the finned heat sinks. The parts I'm talking about have sixteen pins each and have a big "1", "2", "3" on them. Can you take a closeup pic of one or more of those for me? I believe they are semi-custom (not available off the shelf) Hitachi parts, but it would be nice to have the numbers off the tops. If you get a chance?

 

[TomoHawk]

Higuys,

 

There is a discussion on HybridZ by Braap regarding the L6 EFI system, including the ECU.  Basically, there are a few things on the ECU that you could change, but you won't really see any difference. 

 

It seems like the Hellfire replacement by Superlen is the best thing you can do, tuning-wise, but the engine is the real hurdle to overcome.  It's a very nice engine, but they didn't really design it to be really powerful, as we understand it now.