I was having almost identical probs with my 86 Troop, The culprit was found in the end to be a horribly rusted gas tank, and the rust sediment was clogging everything up.
I had the tank boiled out and should be back in tommorow.
So being that you have a 98 vs an 86 and not much rust... Maybe someone put sugar in your gas tank? <img src="/forums/images/graemlins/confused.gif" alt="" />
Did you piss off a neighbor lately??

Also at the back of your engine there is a cap at the top of your fuel line that can be used to remove air bubbles from the line. Make sure that that cap is there or it will cause similar symptoms. (once again, from personal experience)

That's all I can think of,
HTH