An easy maintenance thing to try is always the fuel filter... If you haven't replaced it in the last 20k miles it could be clogged and from then on the motor will be low on fuel pressure, and ANYTHING could make it hesitate.
I've had fuel filters last 70k and be fine, and I've had them clog at 10k, so the only way to make sure is to replace it every once in a while. And when the motor starts acting up, it's a very easy "first step" since it ought to be replaced occasionally anyhow.
My Dad troubleshot a large conversion van we owned for a full year, never could figure out why it would almost die sometimes for no apparent reason. He finally sold it and the guy who bought it later told him that a second fuel filter had been installed during the conversion and it was clogged. That $25 fuel filter probably cost my Dad $8,000 in troubleshooting and eventual reduced price when he sold it.
