Why does a 2001 jeep Cherokee turn but not start?

Check for fuel Check for spark

Could be a host of things:

Bad fuel pump

Faulty Crank Position Sensor (CPS) or it the wire is disconnected

Bad ignition switch

Faulty coil and/or sparkplug wires (e.g. no spark)

The CPS often go bad. They are about $100 at most autoparts stores. Only 2 bolts hold it on, but its a bear to get to. Located (usually) on the bell housing of the transmission on the driver's side almost at the top. Very little room to get in there.