Without more to go on, the fuel filter is always a good place to start. That something is affecting fuel flow is the most logical culprit. Crud in the lines or carbon buildup somewhere can often be cleaned this way: When down to 1/2 tank or less of gas, pour a full tank's worth of injector cleaner in and run the tank dry and keep using cleaner with the next few tanks. The 280 gas engine seems to run better when driven hard too. Remember when Dad used to "blow the carbon" out of the family Chevy? Same applies here. Sometimes something as simple as a high speed highway drive solves the problem...The Italian Tune Up its called.

Next possible cause with a simple fix is to look at the plug wires. Pretty common that the brackets that hold the wires away from the hot engine are broken off. If old wires, lying directly on the hot engine can limit the juice getting to the sparkplugs