Jeep Wagoneer Stumbling Problem

Ok so heres whats going on...
I have an 87 4.0 Wagoneer. It has been sitting outside unused for about
a year. I decided to got it out to take a spin in it yesterday, and
noticed that it will not rev over about 2,500 RPM. It almost instantly
dies. It will also stumble and sputter when I try to accelerate
moderately hard. It seems to me as though it's starving for gas... thus
leading me to believe the fuel pump has taken a dump. Are my
assumptions correct? Or is something else causing the problem? Thanks!
Gary