kia Carnival II leaves during the ride

Moin, As the title already says, our kia simply went out during the ride and no longer went on. One day before the motor light went! Only ! On when he had to work, so mountain drive up. At the normal tingling it went against. Now it just went out. I once threw a look in and found that if I hit this ‘hand pump’ the car and also stopped and also stopped and also took gas.. as I said ONLY as long as I press. I stop it immediately. My Vermu What would you suggest or what could it be? Thx