2000 infinti i30 acceleration problems

My wife and I bought a our Infiniti just over a year ago with 68k on it; since then we have put on another 10k. Around 75k we began having acceleration problems.It seems to choke out periodically after starting the the car (unpredictably). It also seems to hesitate slightly after stops. We have had a fuel system flush, replaced the spark plugs and the air filter, but we are still having the same problem. My wife drives it more than i do, so I have only noticed it a few times. We had talked to a mechanic about replacing the fuel filter but there is evidently only one filter located in the gas tank that is meant to be changed with the fuel pump. Any thoughts?

I would put a pressure gauge on the fuel line and see what is happening.