After many months of tryng to find an ongoing electrical gremlin, I think I may have found it and would like some opinions. The problem has been intermittent loss of power, limp home mode type of symptoms, always cured, at least temporarily by turning off and restarting the car. I have tried many things, changed the AMM, replaced the connectors to the AMM, ruled out fuel delivery problems, replaced cap, rotor, wires, checked hall sensor, cleaned many, many connections, and more, and still the problem came back. About six weeks ago after moving around and inspecting the wires along the firewall and checking the wires on the grey connector on the friewall, the problem went into remission until this week. So, I though that I must be on to something regarding the wires. So this morning I started looking again with the wires being the focus, and here is what I discovered. There is a bundle of wrapped wires that come off of the firewall, bend, and go down though the space between the 3rd and 4th intake on the intake manifold. At that bend there was a crack in the black insulation covering the bundle of wires. This black insulation was very brittle and I cracked off a couple of pieces and found several of the wires with very disentegrated insulation. So, I broke off more of the black covering in both directions until I came to more intact insulation, carefully separated the bare and deteriorated wires, injected clear RTV to cover and insulate the wires and keep them apart, and am waiting for it to dry to try it out. Now, here are the questions: Are the wires that I described capable of causing the problems described above? Do I need a new harness?
THanks for reading my post.
Michael
--
1986 240, 230K, Original owner, Boulder, CO.

Look anything like this?

That's the spot! Looks very similar.
Where did you get your new harness?
--
1986 240, 230K, Original owner, Boulder, CO.

I'm a pretty hard core do-it-yourselfer, so I made a long Saturday out of pulling it and most of the other accessories, cleaning the motor, wire brushing the manifolds and replacing the affected wiring. It has 331K on it now and my goal is 400K if the salt doesn't win. I hope Dave Barton has one for you if that's not the approach you'd take. Everyone raves about the quality.
--
Art Benstein near Baltimore

A bad harness can cause so many weird problems, that it would be wise to plan on replacing yours when you can. Otherwise, your bad harness will always be a suspect in any number of problems your car might have. It's a job, but not that difficult really. We've done two 81 K-jets in our family. It was satisfying. We got one from Dave Barton which worked out fine. My son bought his new from Swedish Engineering (Chris) because he needed one right away. They were great to deal with also. The 86 hasn't shown any problems yet.
--
Thanks to everyone for the help, Doug C. 81 242 Brick Off Blocks, stock, M46; 86 244, 140k , auto.

We've been fighting sporadic ignition issues, nearly identical to yours, and the harness was among the suspects. I, too, found that if I tried to look at some of the wires in the brittle black tape/tubes, the insulation tended to immediately crack and flake. We MAY have found a couple of things other than the harness (having, like you, done plugs, wires, dist. cap, rotor, and now ignition coil); we can't know the problem is solved, but we keep watching and waiting. If we have a recurrence, we have a used distributor to put in (to avoid having to replace the Hall sender); after that, I fear our next step will be the harness.
--
83 240 GL

And if you can't find one in your area cut and paste this into your browser.

http://www.linkline.com/personal/dbarton/WireHarnesses.html

Dave sells good used harnesses for way less than new ones.
--
Dave Shannon
Spring Valley, California (San Diego area)
'84-245 200K+
'84-245T 190K+
'88-240 190K+
'01 Jeep Wrangler Sahara 10K
www.volvo2.homestead.com (new window)

You should start shopping for a used "improved" wiring harness, and quickly. Read the following post for more information:
http://www.brickboard.com/RWD/index.htm?id=733203

FYI, I've found the best deals in my local U-Wrench-It parts yard. A complete engine & ignition wiring harness costs me about $15. The LH Jetronic 2.2 fuel injection system used in your '86 was the same for '85-'88 so any of those 4 years will work for you. The '88 cars did not have the biodegradable insulation, and only pull a replacement '85-87 harness that wears the blue tag (new style) just above the Fuel Injection computer.

God bless,
Fitz Fitzgerald.
--
'87 Blue 245, NA 230K