Wont re-start until turn switch off and then back on?

This sounds like a fuel pump issue.

What I suspect is happening is when you turn the key on the pump is able to prime the system, but the regulator cannot hold the pressure. So then when you turn the key off and back on it shuts the pump off and primes the system again.

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

Once we check the pressure you will want to let the pressure sit there and see if it bleeds off quickly.

At that point, you will want to cap off the regulator and check the pressure again and see if it still bleeds off. If it does then the pump is the issue. If not, then the regulator on the rail is the issue.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

Please see the info attached and let us know if you have questions.