lsejnoha

So my 86 951 is being stubborn. It seems as though for no apparent reason, i will just be driving and the car will completely shut off randomly, I don't know when it is going to happen it just happens. Sometimes it wont do it for a day or two but that is rare. What i mean by that is the engine will just totally cut off, the lights stay on and everything else stays on but the motor will just shut off, but all i have to do is disconnect the negative ground wire that connects to the back of the bell housing behind the motor wiggle it around and then it runs fine again. I just recently replaced that ground wire which literally all it is it the battery terminal cable that connects from the negative terminal to the top of the bell housing it also connects to the body right there next to the battery. OK so heres the deal i want to go into full detail on this because this is just f$@*ing annoying. Before i go into elaborate detail, like i said i replaced that negative wire with another one from a friend. The old one literally was so old and corroded the wire initially deteriorated and broke apart. Now the one that i replaced it with is not brand new and the rubber housing is cracked and broken like my previous wire, I am wondering because the wire isn't insulated like it should be is that the reason why i am having the electrical issue i am having. Should i just buy a brand new cable. Also the positive battery cable may have some cracks in it as well as it is old and brittle as well. i am wondering if that cable is a problem as well. i am also wondering if because they get so hot from being so close to the motor that that might be a reason it is shutting off as well. Please any advice will be appreciated as i am at a loss to why my car is doing this. Otherwise the car is a beast and runs like a dream even though it is 30 years old. its crazy how well this car drives but this little annoyance is taxing. Plus both of those wires even though they are not new both may have some corrosion throughout those two cable both the positive and the negative, should i just replace both of them with new ones. i do think it is because the housing on the cables are not insulated like they should be but i am not certain.
Please advise me as what i should do. Thank you guys.........

lsejnoha

I am also wondering if anyone else has had an issue like this.

JacRyann

Yes, buy a new ground cable. Measure the length you need and get one from local auto parts store. Pep Boys has them for like $10.

If the insulation is cracking, the wires are most likely corroded. Electrons actually travel on the surface of wires. That's why you need multiple strands, to increase the surface area and current-carrying capacity. With cracked insulation, the surface is probably green with corrosion and not flowing much. I bet if you bend that ground cable back and forth a couple of times near the cracked insulation, it'll snap right in half.

Also sand the block around the stud where the ground cable attaches to remove corrosion and expose fresh metal. Also do the same thing to th smaller ground wire from the battery connects inside the battery tray. Also inside where the DME is grounded.

Tom M'Guinn

First off, yes get new cables. Bad grounds create lots of issues. With that said, playing the odds here there's a good chance your problem is actually the speed and ref sensor wires/connectors. They routinely go bad at this age and cause that exact problem. When you undo the ground strap on the bell housing, you are also moving those wires and reconnecting the frayed wires inside. Next time it happens, try cranking the starter and watching it the tach twitches at all. If it just sits there motionless, your not getting the speed/ref signal. Just wiggle those wires and try again ( a few times). If that's the issue, there are replacement harnesses, etc available and lots of threads here on how to fix them.

Grandpa#3

Put some tape over the inspection hole in the bell housing to prevent anything (bolts, washer etc.) from falling down into the clutch area.

Cheers,
Larry

lsejnoha

Amazing. i found the culprit once again.... It was another ground wire. This time it was the wiring harness ground wire that connected on the back of the motor, there are two of them that sit right on top of each other... So relieved OMG#@@#!