Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Topic: Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar (Read 1990 times) previous topic - next topic

Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

August 06, 2005, 02:10:59 AM

I've thought about putting in an 86-87 EEC into my 85 Cougar. The 87 EEC has adaptive strategy and should run better when things aren't 100% normal (and everything isn't after 130k miles).

The only difference in the pin-outs are that the TAB/TAD pins are swapped between the two years. That's easy to fix. The thing that concerns me is the difference in the two VPWR pins. On the 87 EEC, both VPWR pins (37/57) feed all of the actuators/relays/injectors. On the 85, one VPWR pin (37) feeds power to the EEC power relay, while the other (57) feeds power to all of the actuators/relays/injectors. Do you think the 57 pin of the 1987 EEC could be overwhelmed by the greater current it will have to pass?

My guess is that the computer side of the pins are they same, but the harness just changed. Some people might know better though.

Re: Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #1 – August 06, 2005, 08:34:06 PM

The diagrams are drawn differently but look electrically the same to me.
When the EEC power relay/Time delay relay picks it supplies 12v to the solinoids etc. and to pins 37 & 57 on the EEC connector.

Re: Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #2 – August 06, 2005, 10:02:51 PM

Ah, I misread the diagram.

Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #3 – April 06, 2006, 07:06:49 PM

I put the '87 EEC into my '85.

The only differences I can tell are that it starts faster when warm and the light bucking when warm is gone.

Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #4 – April 06, 2006, 09:24:14 PM

Awsome Jeremy. Now your next project is to do an sefi maf setup off of a 91 and up 3.8

Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #5 – April 07, 2006, 04:25:04 PM

I wouldnt mind doing a mn-12 3.8 swap into a older cougar, But I hate wires.

Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #6 – April 07, 2006, 07:04:48 PM

I should have dug this out last summer.

TSB 85-24-12
1984-85 3.8L CFI LTD, T-Bird, Marquis and Cougar.
1. Hesitation during acceleration.
2. Power low during acceleration.
3. Surge at road speeds.
4. Knock, cold.
5. Stalls during cold engagement.

When normal diagnostic procedures do not indicate the cause of the subject drive concerns, install a 1996 design level processor.

Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #7 – April 07, 2006, 11:19:49 PM

Where do you get a "1996 design level processor"?

Questions on installing 86-87 3.8 EEC into 85 3.8 Cougar

Reply #8 – April 08, 2006, 04:48:42 PM

oops!! I miss typed. I should have said: 1986 design level processor.