Green ignition wire
01-17-2019, 08:28 AM
#46
Rennlist Member
I get that, but I've been down this road way too many times. So it's got a running issue (pick any) build your own green wire, problem doesn't go away "Great, it wasn't the wire!"...maybe.
I've worked on these cars where a "known good" used green wire was installed to eliminate that possibility. After many, many hours later of trying to track down the issue a new green wire was installed. Poof, problem solved.
Bonus fun: The previous car which "donated" the green wire never had this issue.
We're not talking thousands of dollars, it's $140 for something that should last another 25+ years and is the lifeblood of the ignition system.
Any running issue going forward that wire will be suspect. It's not worth the hassle or headache.
With your comment I wonder if the new wires are longer than before. When I installed a new one in my 79 there was so much slack I too zip tied it to the cross brace to get it out of the way.
I've worked on these cars where a "known good" used green wire was installed to eliminate that possibility. After many, many hours later of trying to track down the issue a new green wire was installed. Poof, problem solved.
Bonus fun: The previous car which "donated" the green wire never had this issue.
We're not talking thousands of dollars, it's $140 for something that should last another 25+ years and is the lifeblood of the ignition system.
Any running issue going forward that wire will be suspect. It's not worth the hassle or headache.
With your comment I wonder if the new wires are longer than before. When I installed a new one in my 79 there was so much slack I too zip tied it to the cross brace to get it out of the way.
01-22-2019, 12:51 AM
#47
Instructor
Thread Starter
here is a mock-up i made myself just in case. Might try hooking her up, but probably not. Im expecting a green package tomorrow morning. (Today). Cross your fingers that it works
01-22-2019, 06:08 PM
#48
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
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You used what looks like 75 ohm TV coax. The green wire is actually "twin-ax", with two separate conductors running inside the shield. The "coil" in the distributor is actually a Hall sensor, watching as the "teeth" on the ferrous "reluctor" pass by. The signal from the sensor is pretty small, so almost any interference or magnetic/inductive coupling to the signal wires will confuse the ignition box. Shielding both is the only available answer. FWIW, it seems that the connectors are the failure point. The plastic gets crispy and brown.
01-23-2019, 01:05 PM
#51
Shameful Thread Killer
Rennlist Member
Rennlist Member
You used what looks like 75 ohm TV coax. The green wire is actually "twin-ax", with two separate conductors running inside the shield. The "coil" in the distributor is actually a Hall sensor, watching as the "teeth" on the ferrous "reluctor" pass by. The signal from the sensor is pretty small, so almost any interference or magnetic/inductive coupling to the signal wires will confuse the ignition box. Shielding both is the only available answer. FWIW, it seems that the connectors are the failure point. The plastic gets crispy and brown.
https://forum.digikey.com/t/coax-twi...iax-cables/886
01-23-2019, 01:54 PM
#52
Chronic Tool Dropper
Lifetime Rennlist
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Lifetime Rennlist
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My memory must be from a different car. Sorry!
01-25-2019, 01:33 AM
#53
Is it possible to change to a different type hall sensor? I'm not sure the input to the ignition control, but a more common sensor could alleviate the need for the special connector
01-25-2019, 01:44 AM
#54
Pro
I don't know for certain, but I suspect it is the ignition control module, more than the VR sensor in the distributor, that is being picky.
If it were a Hall sensor like later cars use, it would likely be far less of a pain, but with the technology used when these were built, that's a different matter.
If it were a Hall sensor like later cars use, it would likely be far less of a pain, but with the technology used when these were built, that's a different matter.
01-25-2019, 06:20 AM
#55
Rennlist Member
Let us know if it worked --- was the car ever running for you? Or are you bringing it back from being dormant?
I have an 84 16V USA car with an intermittently bad ECU that caused me all kinds of problems. Long story short, swapping it with a loaner proved the source of the problem.
There is tribal knowledge here that can both help and get in the way. I drank the koolaid, and maybe espoused it myself to others a few times, that the controller was bullet proof and would not ever fail. Turned out wrong.
I've also witnessed an incredible "save" a couple years ago whereby the pickup wasn't bad, but it had become unpinned from the distributor shaft. Once that got figured out all was good.
I have an 84 16V USA car with an intermittently bad ECU that caused me all kinds of problems. Long story short, swapping it with a loaner proved the source of the problem.
There is tribal knowledge here that can both help and get in the way. I drank the koolaid, and maybe espoused it myself to others a few times, that the controller was bullet proof and would not ever fail. Turned out wrong.
I've also witnessed an incredible "save" a couple years ago whereby the pickup wasn't bad, but it had become unpinned from the distributor shaft. Once that got figured out all was good.
01-25-2019, 11:17 AM
#56
Instructor
Thread Starter
Let us know if it worked --- was the car ever running for you? Or are you bringing it back from being dormant?
I have an 84 16V USA car with an intermittently bad ECU that caused me all kinds of problems. Long story short, swapping it with a loaner proved the source of the problem.
There is tribal knowledge here that can both help and get in the way. I drank the koolaid, and maybe espoused it myself to others a few times, that the controller was bullet proof and would not ever fail. Turned out wrong.
I've also witnessed an incredible "save" a couple years ago whereby the pickup wasn't bad, but it had become unpinned from the distributor shaft. Once that got figured out all was good.
I have an 84 16V USA car with an intermittently bad ECU that caused me all kinds of problems. Long story short, swapping it with a loaner proved the source of the problem.
There is tribal knowledge here that can both help and get in the way. I drank the koolaid, and maybe espoused it myself to others a few times, that the controller was bullet proof and would not ever fail. Turned out wrong.
I've also witnessed an incredible "save" a couple years ago whereby the pickup wasn't bad, but it had become unpinned from the distributor shaft. Once that got figured out all was good.