BRAVO 4x4TURBO rally car.

The car is a Fiat bravo but it have a lancia integrale turbo engine and gearbox.

Somebody else made the car, but there were several problems with it. Now we made the car usable. Everything is OK now, except one problem. This problem was also with the old 1.0.46 firmware before.The car sometimes stoppes and won't start until the ignition is turns off and on again. What could be the problem. The car using 1.1.27 firmware now,from here:

Here are the config files:

The car stopped now one times during a day. Unfortunately i have no log about it:( It was accelerating, revving till revimit and gearchange to the 3rd gear, than the car stopped. Igntion off and on and the car was running again.

What could be the problem?