2002 Nissan XTerra. Started and went to lunch. Got ready to go would turn over but not start. I'm thinking fuel pump?

Most Vehicles DO NOT HAVE An Emergency fuel cutoff Switch . This was something ford did in the early 90s but now the computers can communicate and disable the fuel pump if necessary. Try disconnecting the battery for about 30 minutes or so. If it still won't start try listening for the fuel pump....it should run for a fee seconds when the key is turned on

Starter motor failure?.

its out of time a little have the timing checked and set

I have a customer with a 2000 Nissan Xterra 3.3 liter V6 with 180k miles. He stated that while driving on the highway the vehicle is fine. Once he exits the highway and drove on surface streets the engine stumbles, sputters and shuts down when he stops. The fuel pump is located under the right side rear seat. I removed the inspection cover to view the electrical connections. No problem there. I drove the vehicle for approx 20 minutes and it hesitated a little but not enough for me to come to a good conclusion. I needed the engine to heat up some more so I drove to Panda Express for lunch. I got my lunch to go, return to the vehicle and started the engine to eat while the engine idled. After my lunch was over I drove back to my customer's house. On the way God bless me with what I was searching for...the engine started to sputter. To shorten this story I replaced the distributor with a brand new assembly from AutoZone($233.65). Once I removed the factory distributor I spun it by hand and that's when I could feel that bearings were rough & worn.
Problem solved and my customer is happy.

Check your fuel pumps wiring.

Inside the fuel tank

most likely the fuel pump. First check fuel pump relay, listen for pump coming on when you turn on the switch. If it does, try changing the fuel filter next.

the fuel pump may be working but not putting out enough pressure to start. Try removing the intake hose from the throttlebody and spraying a small amount of starting fluid in and see if it starts if it starts and dies you need to replace the fuel pump

Sending unit died. can be expencive to replace since most sending units are integral with the fuel pump now. lots of labor too. Better to use the trip odometer till you can afford a day without your car and a $600.00 +labor repair bill.

I am no expert, but I just had a similar problem. The car would shake and buck when accelerating. It finally just died and would not start. After sitting for some time, the car would start and run a while, then do the same thing. I thought fuel pump. The dealer diagnosed distributor. After replacing, the car is running perfect. Something to think about. Good luck.