Fox T-Bird/Cougar Forums

Well to me anyway. I took my TFI off my distributor just to check resistances, and it came out good. Then I pulled the EEC out again and looked it over for any visual defects (hot spots). It's 26 years old so I thought I would replace the three electrolytic Nichicon 47uf, 10v capacitors being they do go bad with time. Two were right in the ball park, but one was getting a reading of 3.5uf. I replaced them all with new Nichicon 47uf, 100v, (plenty good). So tomorrow I will hook it back up and see what happens.

Was it having issues that led you to do this?

I've had several strange electrical issues with this car. I believe more in "better safe than sorry" than "If it works don't fix it".

What type of issues?

Mainly timing. It would run at 10 degrees ATDC smooth and powerful, but when I moved it to 10 degrees BTDC it would run rough and smoke. The plugs would also turn black. Strange!

Should be interesting to see if that fixes it.

I went to a local auto store to buy a re-manufactured one about a month ago and they wanted $99.00 for it and $76.00 for a core. There also seems to be about a hundred different ones to choice from. When I looked at it I was shocked at the paint job and labeling it had. Looked like a five year old fixed it. I wanted to keep the core and rebuild it myself, but it's hard to find the right schematic for it. I found one that gives me the resistor and cap. values but it's a little different form the EEC I have. The schematic I saw said that all resisters are 1/4 watt unless labeled otherwise. There are quite a few that look more like 1 or 2 watt resistors. I guess I could build it with 2 watt resistors where they will fit. Most of the time I need to take the resistors off the board in order to tell if they are still good. If I could find the right schematic I would love to rebuild it with higher quality parts and could order the parts all in one shot. The problem with trying to read the color codes on the 26 year old resisters is the colors are hard to read and reading the values with test equipment is no good unless they are still good. So, it is imperative that I have a good schematic to work by. I will probably still work on it some more, after all this is the brains of the outfit.

I just found two bad resistors in the same vicinity as the bad capacitor. No turning back now.

Nope, now you're making a reman PCM.

Hope it works out. If it does, maybe you can do a write up on it.

I'll be interested to see if you find a common denomniator,,,
like components in or on entry of pin #X  are effected.

I'm ordering parts tomorrow, so it will be a while before I can finish up this project. I will keep you informed.

any progress yet,,,?

and you know we need pictures!  : )

I got lucky, I was able to check all the resistors right on the board. The two resistors that I had thought were bad were good, the colors were hard to read. So, all I found was one bad electrolytic capacitor out of the three. Being they were all old and inexpensive, I replaced them all. I haven't had a chance to find out what it will effect yet. Thanks!

i wasnt even thinking, i could have (still can) done a stare and compare with one of my EEC's to help you make out colors and such.

btw, i think santa got me a huntron!!!!!

can you imagine how convienient it is to be able to check caps, transistors and such without lifting a leg?

Here is my EEC in stock form.

This is what the electrolytic capacitors look like. I replaced all three of mine. Mine were 47uf in value. One of these was at 3.5uf (bad).

Here is the third capacitor hidden at the end of your board.

Here is one of the resistors I replaced. It is listed as R1 on the board. Value is .51 ohm, 1 watt resistor. The stock resistor is carbon, either a 5% or 10% resistor. I replaced it with a 5% carbon composite resistor. Also I advise using good quality capacitors as well. I used Nichicon Capacitors the same as stock.

It is best to read the resistance on your resistors with them out and personally I make sure I'm not touching them. Here is the 2nd resister I changed, also a carbon resistor. This one is listed as R69 and I could not locate it on this schematic. So, the colors look to be Brown, Gray, Gold and silver which comes out to 1.8 ohm @ 10%. My stock resistor reads 2.4 ohm, so I will replace it.

That's all I'm going to do to mine for now. I took out the vulnerable items that have a tendency to go out first, just about every thing else is pretty much bullet proof. If any IC's or Proms go out (small black boxes w/legs) your probably better off just buying a rebuilt unit unless you feel ambitious. I have yet to the put the computer in the Cougar and see what happens. I will let you know.

This is what my new resistors look like.

I've got an EEC from an '86 5.0 Stang that I'm doing nothing with if it would help your cause...?

TBS302, 
            I'll let you know if mine works out alright or not. Thanks for the offer!

No worries..it's for an HO engine, so if you decide to buy it, just wanted you to be aware :)

It's been a couple of days, does it work?

So been following this with absolutely no idea what you are trying to do and or accomplish. After replacing all these components what are you expecting will happen???? I for one dont have a clue. I was always of the  belief that those capacitors were a filtering device for rippled ac signals. Now the question is if they are not up to specks will they hurt anything. I am assuming NO. But will give you the benefit of testing it and posting the info. Without the prints on the ECM how can one even know what those components do or are designed to do. ?????????

I don't think I ever saw a resistor go 'bad' unless it was in the path of a high current overload in which case it's visually obvious.

Not sure what the weak link would be in a board like this but could be PC board opens due to thermal cycles more than faulty components.

I'd be careful with ESD (Electro Static Discharge) when working on the board. Not sure how well the IC's are protected, but they should be pretty robust.

Interesting project, keep us posted.

He DID have a dead cap.  Or at least nearly dead.  If the timing problem he was chasing is caused by timing out of phase, it's possible that the PCM was responsible for F-ing up the timing, but it would only affect timing with the spOUT in place.  And we ALL know to pull the spOUT before we set timing.  So, it seems to me that he must have thought this also, and in thinking this way, he pulled the PCM, opened it, and measured components.  He clearly knows how to read a resistor and measure a cap, so I would put forward that he's much more in his element with electronics than driveability, and if he really HAS found his problem, he deserves a pat on the back.  If he hasn't, well, better luck next time.