I have a 96 VW Golf IV and it acts like there is a gremlin with his hand on a “run/don’t run” toggle switch. It has stopped while idling, and at highway speeds. It has restarted immediately, and it has needed a couple of minutes to decide to start again (highway shutdown). The engine either works, or it doesn’t. There is no middle ground. The rest of the electrical systems work fine (radio, fans, lights, etc) at all times.
The local mechanic thought it was the ignition in the steering column, but changing that didn’t make a difference. I re-seated every connector I could reach, and research has mentioned other items like the Hall sensor and fuel filters, but I didn’t want to start an easter egg hunt.
If anyone has had this happen and managed to solve it, or has some thoughts on how to proceed, please let me know. I think the mechanic is about to resort to replacing random parts.
As I recall it has a main relay (#106 or maybe #109). I don't seem to recall it disconnecting while running however and it may be a diesel only item.