BMW 3.0 D 2004

When driving with kick-down this error pops up; "Einspritzanlage".
Which means something like injection system.

After switch off the engine and starting agin it stys away till doing more then 3.000-4.000 rpm.

Car has been tuned up to stage 1; 258 bhp and 580 Nm

Does anybody have an idea what it can be?

Thanks in advance,

René