Gasoline in diesel fuel will change the chemistry of the fuel.
By changing the chemistry of diesel you have increase the flash point and reduced the lubricity of the fuel. The fuel will fire sooner that it should casing engine damage and with the lubricity reduced you are going to kill you injector pump and injectors sooner than later.
Is you engine running rough?
A diesel engine with a mix of gasoline in the fuel will cause the engine to run rough and do damage.
If you THINK you have gasoline in the diesel fuel tank? There is only one way to find out for sure. A simple test from Dieselcraft will tell you in less than one minute if gasoline in in the fuel.
If you do not test and continue to run the engine you could kill that expensive engine in only a few minutes of running.
Go to https://dieselcraft.com/fuel-test-kits/