Look for oil in the spark plug wells. If there is oil, you will need to replace the valve cover gasket Look for oil in the spark plug wells. If there is oil, you will need to replace the valve cover gasket
fuel filter
If your Ford Aerostar sputters at high speeds, you might have a problem with the fuel injection system or with the fuel filter. You could also have water in the fuel lines, bad gas, or even a spark plug fouling issue.
the fuel filter has been changed.
Maybe dirty fuel filter.
try both tuneup and fuel filter change
Possible clogged fuel filter.
The Sputtering tends to be a old or clogged fuel filter the engine is getting starved of fuel replace that and it should fix the problem
fuel filter,fuel pump low pressure
Had the same problem, the problem with mine was a hole in the vacuum line, listen for hissing noises
Try changing the fuel filter.
Try checking the fuel injector and carburetor
Change your fuel filter. If if it only does it when the engine is hot, check for a coolant leak.