Hi Guys
New to the forum, would like to say hello and could any one help.I have a 1985 coupe 4+3 Tranny. When I picked it up it seemed to run fine but idled erratic. In going over everything I found #6 plug wire just hanging, thought I fixed it. It didn't I found the # 6 plug loose, no fix finally found vacuum hose off, wal la. In all of this realized that the check engine light was burnt out. Put new bulb in only to realize the light was on all the time. Code 42. Electronic spark timing. Changed ignition module, as per manual, no fix, checked timing at 2000 RPM with est wire connected and then disconnected, no change in timing mark, must be the ECM. Put in a Reman today, I have found out the light is winning,it's still on. I also found as I was pulling out the ECM there is a little black box in front of it about 2"x2" 1/2 " thick, open at one end with a circuit board in it that can slide out. It has 5 wires running to it, It was getting warm, come to find out the plug was starting to melt. I brought it down to the dealer and they had no idea what it was or what it did. I taped the plug so far so good.
If anybody has any ideas on any of it or all of it, I'm all ears
Sorry for the long post
Gary

 

Just to let anyone know I found the problem. As a final attempt I was going to replace the wire harness from the ignition module to the ECM. When I tried to remove the plug I found I couldn't pull it out from under the distributor. As it turns out one wire was crimped under the distributor melted and frayed. Replaced and runs like new. I beat the light

 

good to hear you found it-you know what, I did the same thing to my 87 once. We need to keep a close eye on those because it's so simple to do.