Chosen Solution
Keeps reving up and down
As this is a fuel injected and not carburetted, there could be restrictions in one or more injectors. There could also be a vacuum leak somewhere. The best solution (requires a mechanic with the correct software) is to connect to a computer and diagnose by checking what the different sensors are doing / telling, when the engine is idling and surging. I mostly work on carburetted engines, so my fuel injection expertise is limited
