It works fine for the first 10 km or so, then it'll suddenly stop accelerating, as if I weren't even pressing the pedal, and I have to restart the machine and it'd work again, for at least other 100-500 meters before failing again. It usually happens when I release the clutch to shift gears, or when I stop accelerating and try to accelerate again.
I've already changed the oil, the fuel and oil filters as well as the sparks, the injection system is clean. I've also checked the pedal and it's ok.
What could be causing this?
It's the 2002 German version of the Corsa, it wasn't made here in America.