Whilst travelling along the motor in our 1995 five-cylinder petrol VW Transporter will suddenly lose power and finally cutout. After 5-10 minutes it will restart and you can continue your trip, sometimes up to 200 km without any more trouble. You might not have this problem happen for another week, or even a month, but it could happen the next day or two or three times in a day. The last time this occurred it would not restart and had to be towed home. Our mechanic has no idea what the problem could be. The motor has never overheated, the radiator is still full, there are no oil or water leaks visible, or evidence of water in oil. What do you think the problem could be?
I don't believe the problem is related to the engine itself, instead I would be looking at the fuel and electrical systems.