**Ok. We'll for them that don't know the fuel flow gauge is a pus sure gauge calibrated in flow. A blocked nozzle will indicate a higher full flow as it is a direct measurement of the fuel px. Basic engine 101
Cheers**
Not in all cases, or in a degree discernible to the pilot. That is an over-simplification and is erroneous. Many FF gauges are not simply pressure gauges.
I'm finding that one can only be certain about that which is insufficiently understood. Advanced engine 201.