Sputters and shuts off when below half tank

More than likely you have a purge valve issue as it allows fuel vapor in the engine at different times and it would be the only thing that would be affected by the level of the fuel tank. Basically what happens when the engine starts to sputter and shut off is it is starved of fuel or too much fuel.

This means we need to test the purge using the testing below in order to find out if this is the issue.

Normally this happens with a purge valve issue when you fill the tank but the valve could be getting stuck so it is critical that we ensure it is only happening when the tank is below half so fill it just above half and test this a couple times.

then we will need to test the fuel pressure just to be sure the pressure is not dropping when this happens.

Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please run through all this material and let us know if you have other questions.

Thanks