Ignition spark problems

[roadrunner-europe]

Hello to Everybody,
I have a Problem and I don´t know what I can do more.

Last summer I drove to a friend and about a half mile before I arrived at his home my engine turned off. I thought it comes from my autogas arrangement, so I restarted and continued my way. Two weeks later in the same road (that´s not a joke) the same story. When I arrived at my friend´s home, I told him this story and he began to laugh. I told him, that my car dislike his road, cause even when I entered it, the engine turned off. I have never thought, that this is the beginning of a nightmare.

One day in fall the engine turned off again and I crank again. This time without result. So I call a friend and he came and he tows me to my garage. We find out that there was no spark. So we controlled everything, but we´ve found no fault.
To be sure, the next day I ordered some spare parts. At the next weekend I change everything. Crank the engine – no result. The engine kept off. The starter turned but the engine don´t start.
These are the parts, which I changed:
Distributor cap
Ignition coil
Distributor arm
Ignition module
There is a module with slotted holes to adjust on the steering column connected via a bar with the starter lock – even changed

Everything without result. The engine kept off.
Not far from my garage, we´ve an us-car-dealer. He is a good friend meantime. I spoke to him and he gave me a high performance ignition distributor which produce 65000 volt. I thought that this was the solution of my problem. Returned to the garage and built it in, crank – nothing. Dismounted and brought back. This was all on a Saturday.
Sunday I returned to my garage and tried a few other things.
Placed a wire from battery+ to the ignition coil, and a conductor from battery- to the bottom of the ignition distributor to eliminate ground problem. Nothing changed.
And now comes the unbelievable but truth: one week later I returned to my garage, open the truck, crank and this holy piece of s… started. No one touched this car for the past week!!! Why does it start?
Since this day we talk about “Christine”, when we talk about my truck.
This happened several times. But I never can say when. Sometimes it runs a week, sometimes a month, I´ve even had that I started the car, drove out of the garage, turned it off, washed my motorbike and after that we wanted to drive to a meeting and I can´t start the truck again. Same problem.
Anybody there, who could help me with some new ideas? Have try a lot of ways. Have help from a truck mechanician and an electrician. None of them know anything more. Even the dealer hasn´t an idea.
I hope that I´ve explain my problem well.