1996 Ford Explorer get? Electrical problems? Help me please?

I have replaced the fuel pump 3 times. Had a ford diag. Check and replaced all recomended parts but when ever I reach 55mph it shuts off(leaving me on the side of the road) it can take from 30 min. To 3 days before it will start again. So im thinking electrical. However, ive been told that there are 47 different computer chips for this make. What do I need to do to this thing. The last fuel pump had me running great for about a month then.55mph. And she just shuts off. No one seems to know what the problem is. So I come to the great people of yahoo answers please hook me up:}