Issue with Rough Running Above Half Tank in Toyota Yaris 06

[Marre]

Hello,
I have an issue with my Toyota Yaris II hatchback 06 (type: XP9F(A), variant: SCP90(H), version: SCP90L-CHMGKW(1A)). When I fill the fuel tank over halfway, the car starts running roughly. It jerks when I accelerate, engine brakes heavily when I release the gas, and sometimes stalls if I press the clutch. At a standstill, I have to keep it running by revving over 3000 RPM; otherwise, it idles shakily and eventually stalls. This problem only appears when the tank is more than half full.

When driving at higher speeds, the car runs somewhat smoothly, but at lower speeds or low RPMs, it jerks and feels like it’s going to stall. Once the fuel level drops below half a tank, the car runs normally again. I don’t usually fill the tank fully, so I’m unsure when this started, but I noticed the issue this spring after a full tank.

[TonyHSD]

These can be so many different things. 
Start with services your car then use better quality fuel, add some fuel additives. Take the car for a longer drive. Clean throttle body. Run a diagnostic to see any fault codes to start with.