Lincoln running rough

I have a 1991 Lincoln Continental Executive Series with approx 250, 00 mileage. Engine size is a V8.

When driving the vehicle, it is very rough.
It's seems not to be getting enough gas while driving(sometimes only) rather it be driving fast our slow of the freeway. It doesn't matter.

It's like the car hiccups when driving.

Any ideas what could be causing this (i.E. Fule pump? Fuel line?)

Thanks