I had a problem the other day where the igniter's failed to light up the engine. I said fuel off, continue to motor, fuel is coming out of the engine. 2nd go she lit up after switching igniter's.
Other problems I have had basically are back to gate faults, where I have had to say to the crew shut the engines down and I am towing you back to the bay. Other times for the MEL book I ask them to look it up and see if it is a O or M req. Pretty easy when you think about it.