94 park ave stalls while driving

my park ave just cuts out while i'm driving but starts right awayafter and runs good till the next time it stalls. I had it at the gas station but they couldn't find the problem.....so i took it to the dealer and they had it for over a week and could not find the problem after numorous parts changes they made any suggestions?

What items have been tested or checked? I had a problem with my 96 Park Avenue and I diagnosed mine and found a defective fuel pump. It was getting hot and shutting down after about 10 miles of driving.

i'd imagine everything was tested including feul pressure