No, it is not okay to leave the vehicle running and attempt to empty the tank that way. Leaving the engine running while trying to empty the tank with the drain plug open is potentially hazardous and could result in a fuel leak.
In addition, leaving a diesel engine running with improper fuel can cause fuel system component damage. Diesel engines are designed to run on diesel fuel, and using an incorrect or unsuitable fuel can cause serious engine problems, including reduced performance, increased emissions, and expensive repair bills.
If you have accidentally put petrol in a Transit Connect diesel tank, it's crucial to stop the engine immediately, disconnect the battery, and contact a professional mechanic or recovery service. Do not attempt to fix the issue yourself or leave the vehicle running in an attempt to empty the fuel tank. The diesel fuel system in the vehicle will need to be flushed or cleaned by a qualified mechanic to remove any residual petrol and ensure proper engine operation.
