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EEC-IV FBC-1SC3 8K MROM
E5DF-12A650-H2A AH
6EC2339A06 4963 - 307 6G26


This is the original computer for a F150, purchased in December of 1985. The location was Alabama. It was not specified for California or high altitude.


Hope this will help!

 

Thanks for the information. That does help out. I'll post more later. I'm at work now.

 

I purchased some soldering supplies and recalled some 30yr old soldering skills, and I wasn't very good back then either. I cleaned up the terminals as best I could and this is what I ended up with.



Put the thing back together and put it in the truck. The only codes I get now is the 68code. I am pretty sure this is the Idle Tracking switch. Unfortunately I left that switch on the old carburetor when I returned it. Im not sure how that will affect the truck overall. On a test drive the truck drives pretty erratically. I may have not achieved a good connection. I think I will take it off today and try again.

If that doesn't work, I got a hold of Cardone and they said the best option is to send it to them for refurbishing.

Option three is to find another computer using the numbers that 1986F150six was so kind to give me.

I still wonder how different the computers/truck hardware are in the different trucks. I understand there could be differences between an automatic and manual computer but whats different between a high altitude truck and low altitude truck besides tuning. Are there different sensors on them?

Craig

 

I cleaned up around the soldering area, and checked my connections. It is actually pretty solid. The truck runs poorly now.

Is there a "relearning" period for the computer?

 

Pulled codes to see if there were any in stored after going around the block.

Still getting the 68- ITS failure in the KOEO then for stored i get a 13- idle RPM out of spec?

BUT- during disconnection of my reader I accidentally moved a wire with my sleeve which caused the reader to beep. I tapped the wire again and the reader beeped again. This wire comes off the negative battery terminal and the source of the problem is a crimped connection to a black with blue or green dots wire in the harness. I see this same color wire at the computer in triplicate. I cant find this wire on my diagram however.

 

Well, congrats on getting the computer up and running again.

At this point, I don't think there is anything more to gain in the ECU. It is working and no replacement, or Cardone rebuild will make it any different.

To try and answer your questions, the difference in the EECIV computers used in various models are in the programming. Think of the ECU as a box of inputs and outputs. The program, which runs in the ECU processor decides which I/O's are used and how they relate. In your case, the application is an electronically controlled feedback carburetor which uses quite a different arrangement of controls than an EFI application would use. In theory, you should be able to replace the program with something compatible with your application, but the manufacturers have encrypted the information to a level that would make the CIA proud. This, in turn, required specialized tooling and programming subscriptions that keep on making money for the manufacturer. There also is the issue of obsolescence, and the process used in the EECIV computer has been outdated for 20 years. Kind of like trying to keep your 80's style cellphone operating today. The technology used back in EECIV days also used PROM technology which burned the program onto one use style memory chips. Reprogramming would require replacement of the memory chips, or substitution via the "J5" connector. Even then, a lot of the basic process was "mask programmed" into the processors and it just is not practical to reprogram the ECU to another configuration. Bottom line for you is you must find a computer compatible with your application and the EECIV equipped feedback carburetor system is unique. Ford actually used the EECIV structure to make a transmission controller for the E4OD transmission with the early diesel trucks that did not provide any engine management at all. Looks just like your computer, but neither would work in the other application.

Now, on to your current problem. You need to track down and fix the cause of your 68 code. You have already done this for your other codes and I'm sure you can do this one. It may be helpful to not think of the codes as pointing to something that must be replaced. Often the symptom reported by the code points to a problem that you still must diagnose. e.g. the low RPM code in your stored codes is a report of a condition. It does not point to a specific component failure.

Some driveability problems will not show up as codes. For example, plugged fuel injectors may not set codes, yet your engine will run terribly, maybe not at all. It all comes back to the basics, fuel, ignition and compression. Which one is missing?

Just a thought on your mystery wire. Can you identify the ECU pin # it connects to?

 

Thats great information and helps my thought process about the computer. Thank you for the explanation NotEnoughTrucks.

The 68 code is ITS. This component, unfortunately for me, was attached to my old carburator when I sent it back for a core, after receiving the new carb. I am in the process of finding another one.

Next time I have time, I will check which pins are associated with the mystery wire. All I remember is there were three of them all on one end of the plug. I will absolutely fix the shorting wire ASAP too.

 

This may be the end of this thread.

I soldered the shorting wire near the negative terminal to the battery. No more problems there.

I eMailed Guaranteed Carburetors, and Butch emailed me back the next morning saying that he was sending me an Idle position switch with the bracket back to me. He wouldn't even let me pay shipping. It arrived in the next couple of days. -Thanks Guaranteed Carbs- Im glad I purchased from you.

Anyways, mounted that up. Now I have a clean KOEO 11 response. The only thing, at this point, in stored codes is an engine temp sig too high. And the truck runs poorly.

I did some research and thinking...... What about the EGR? I disconnected it and the truck didnt have the hesitation anymore, but it was sluggish consistant. Took the EGR off and played with it. The plunger moved and there wasnt much buildup on it. The thing wouldn't hold a suction. So new EGR needed.

I ordered one from oreillys this AM, decided to flush my radiator and put a new thermostat in.

Oreillys called me about noon with the part. I put the EGR in, flushed the radiator and put the new thermostat(195deg) in. The old one wouldnt open up fully. The truck runs great now and cool. Only problem is now I can really tell the clutch is slipping. Thats for another thread and after I get some motivation to lay on my back in the dirt this winter.

I want to thank everybody for the advice and encouragement. I probably would have sold the truck for scrap if it wasnt for you all. I learned alot and am pretty impressed with the engineering that went into this truck back in 1984.

Craig

 

Thanks for the update, it sounds like life is happier.