I have run out of fuel (car kills), twice now when the gauge shows 1/3 to 1/2 full. After adding a gallon and getting to a fuel station, only 10-12 gallons are needed. I brought it to my "no longer" trusty mechanic, who replaced a "float", but no change. I get only about 275-300 miles before it will kill on me.

So, it seems I am running out of fuel with plenty of fuel in the tank? Does this seem possible, is there something that could be stopping the flow of fuel with a third of a tank remaining?

1991 300D turbo.