911 SC No Spark Help Needed

[garyly]

I purchased a 1983 SC cabriolet a couple of weeks ago. The car passed a PPI and ran very well for most of ~120 mile drive home. Then the fun started.

About five miles from my house, I experienced a slight hesitation going uphill.
That worsened progressively and the car died about a mile from my house.
I got the car restarted and into my garage, but the car was running very rough. After reading the forums, I replaced the relay under the passenger seat, but the relay did not fix the issue. The spark seemed weak, so I replaced all plug wires, distributor cap, rotor, and ignition coil The problem progressed to a crank but no start condition, though I did get the car to start once after I got the new coil. It ran for about 5 minutes; somewhat rough at first and it started to smoot out. I thought I was in luck, but then the car died... Since then, I have discovered that I now have no spark.

My "green wire" looks okay but I realize it could be bad. The CDI box makes the squealing noise as expected.. I tested between pins 31D and 7 at the CDI connector for resistance and I got nothing (no reading at all). Does that mean that the green wire is likely broken?

Does anyone know if there is a procedure for replacing the green wire with removing the distributor? I've read countless posts and I'm somewhat at a loss at this point. I would appreciate any suggestions

[gomezoneill]

The distributor wire is easy to replace. You might want to check the tdc sensor and the reference sensor values.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiK-7asmqDsAhVPXM0KHerwAcsQrAIoAXoECAUQAg&url=http%3A%2F%2Fforums.pelicanparts.com%2Fporsche-911-technical-forum%2F667659-replacing-3-2-reference-senders-engine-car.html&usg=AOvVaw1uJ-R4QrVqVQYNMdaB-H7q

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiK-7asmqDsAhVPXM0KHerwAcsQrAIoAnoECAUQAw&url=http%3A%2F%2Fforums.pelicanparts.com%2Fporsche-911-technical-forum%2F893183-reference-sensor-testing.html&usg=AOvVaw0sdB1Zd8YIbZy7Z8VHSYPl

[AndrewCologne]

@ gomezolli
I think you refer to part which comes in a 3.2 but the 3.0 from 1983 does not come with a TDC sensor like the 3.2

@ garyly
Check these CDI testing approaches, its in german but google translator is your friend:
https://www.911-hkz.de/HKZPruefung.htm (Gerberding is the CDI/HKZ godfather in Germany)
http://www.klassik-stammtisch.de/porsche/hkz/hkz_ueberpruefen.pdf

There its also explained how to check the distributors inner inductive coil for proper resistance.

And, ... never promise 100% in new produced parts like your ignition coil. The quality is far away from the quality keeping restrictions Bosch was known for in the dacades from the past. Compared to new old stock, most of their hardware now lefts factories in china etc. where many poor/flawed devices were / are / will be thrown on the marked

[JSV798]

When the green wire failed on my 1978SC there was continuity between 31d and 7 which meant the insulation had broken down. So check for continuity. My meter has a buzzer for checking continuity; alternatively there will be zero ohms resistance when it should be infinite.

[gomezoneill]

oooooooppps sorry.