What are you using to measure the fuel used? try MCDU MENU, <PLANE MENU.
That will indicate BOARD FUEL (LBS) to the nearest 1LB, (the total displayed on the MFD's only shows to nearest 10LB).
How long are you taxing for? whats the fuel burn when in the air? Is this problem repeatable? have you tried loading the aircraft "engines running" and "cold and dark"? ensure that X-Planes MTBF option is unchecked. Try loading a default aircraft e.g. C-172, wait for it to load, exit X-Plane. Restart X-Plane, wait for C-172 to finish loading, then load the CRJ-200, do you still have the problem.
If you still have problems, try using X-Plane's SAVE replay option, zip the .rep file and attach to your next post, along with your Log.txt file.
You could also use X-Planes, Settings, Data Input & Output, then Data Set to tick "disk file" and "graphical" next to each of the following datarefs: times, N1, N2, FF and fuel weights, etc. to log/display the rate of fuel being used.
Does the fuel flow tie up with the reduction in the fuel left in the tanks? or have you got a leak?
At 40% N1, taxying, my CRJ is burning approx 1510-25 lbs/hr each engine, that's approx 1lb/sec (total) decrease in Board Fuel (MCDU Plane Menu).
cessna729.