Decarbonising a diesel engine motor

Tried the water spray method yesterday. Sprayed water in at the EGR valve. Hope that's 'B' in the picture as that's were I sprayed in the water. Engine was at normal running temp. Got plenty of steam vapour out of the exhaust.
Didn't get the revs up though as on my own Just run at tick over circa 800 rpm. Engine didn't stall. Put hoses back together and gave it boot on the drive and a load of soot on the floor.

Went for a drive and feels as though I have no boost as the motor doesn't respond as it did. What could be wrong?

How did you spary it into the engine and how much of it? You would want the RPMs to be pretty high when doing this.

All sorted. Taking erg bend out I'd dislodged a vac hose