It does not happen very often, but when I was commuting from college to home I was on interstate going about 80mph with a/c on and car suddenly acts like no fuel being supplied and it just dies. So I pull over and sit for 30 seconds and it starts right back up, I go for a few miles, happens again. Does this about 6 times and then does not happen again until I reach college which was 15 miles from last breakdown. It just happened again the other day going about 45 mph in 85 - 90 deg weather. Fuel pump did not sound too good when i turned ignition to " ON " as i was priming fuel pump, after turning ignition on and off a couple times, it started to sound like a normal kind of whine like it always has. Does not through any codes either. Upper intake manifold replaced, new plugs and wires, new fuel filter. Suspecting bad fuel pump? Any help would be greatly appreciated! Thanks.