We need to start with checking the fuel pressure. It could be a leaking injector but if may only be leaking because the regulator is over pressurizing the system.
We don't have a manual on this vehicle as it is not offered here in the USA but the theory is the same.
Here is a guide that helps with checking pressure:
The only way it can run on like you are saying for a second or two is if there is unburned fuel in the camber and it is hot enough to ignite it when it is compressed.
Can you get a video of this happening and we can confirm this is actually run on and not just the engine shutting down? Also, does it do it every time or only when it gets hot?
Let's start with this and we can go from there. Thanks
Saturday, February 6th, 2021 AT 3:59 PM