The 1979/1986 model 928 (16v) have a distributor with a sensor. That sensor connects via a coax like cable called the "green wire". Why this name? It is simple: it has a bright green color. And what is so special about this wire?
- nothing really, it is a rather simple coaxial sensor wire
- the connection at the distributor side a special. You won't find them anywhere
- the wire tends to get brittle and fail over time, causing ignition problems
- all used ones are in similar condition
- Porsche sells them at astronomical prices
The 911 uses a similar wire which is shorter. Maybe some modification makes it usable for 928. Also 3D printers printing the connector in ABS might be an option.