Had to have van towed to garage

Had to have van towed to garage. Cutting out, not responding to gas, sputtering. Mechanic informs me that in trying to diagnose, the van has "no memory." So what would cause this? I feel its the fuel pump, and he says he has no way of knowing where to begin as there are no codes, no memory. He wont replace fuel pump unless it is a factory warrarnty mercury fuel pump which will cost me around 500, and with labor, around 800 job. I have had no problems with this vehicle til now. I am visiting my sister in california and waiting to have surgery, and now this. I have replaced with a new battery about 4 months ago. No engine light has come on. On a couple occasions this past year the speeddometer was wacky but seemed to clear up. Replaced headlight bulbs, but that was it. What do I do?