It not starting after a hot run is a typical issue with the Cherokees called "Heat Soak"
There was a TSB for the late models where this problem is most common.
Heat soak leads to vapor lock. When the air/vaporized gasoline in the fuel rail clears, it runs normal again.
IF It gets too hot in the engine bay, "The Chrysler Fix" is to wrap the #3 injector.
If you want to confirm if you have heat soak--drive your vehicle until it is
good and hot. Park, shut off the engine, and open the hood for about 30 minutes. Restart the engine. If the symptoms are gone, you have heat soak. The only fix is to reduce the under-hood temperature.
Most other manufacturers that encountered this problem simply added a timer circuit in the efan to allow it to run when the engine is off for a short time to reduce the under-hood temperature. Chryco--a cheap piece of insulation.
The heat soak issue for the 1999-01 XJ is due to a number of issues. Redesign of the fuel system eliminating the return line from the fuel rail was a start, followed by the redesign of the manifolds, and compounded on some XJs with the addition of the 50-state emissions package--two pre-cats in the exhaust manifold right under the injectors on the 00-01.
another change Chryco had was to change from Champion plugs to NGK plugs in the effected model years.
I would recommend you come up with a way to reduce your under-hood temperatures. You can go the route of hood vents (louvers, or Lebarron vents)
Or you can install an after-market timer to the efan circuit. Here is a link:
http://www.at-fairfax.com/P1786-ELK-960.htm
I would also think about maybe swapping out your thermostat, and making sure you have proper coolant level, and that its not all water. You want a good 50/50 mix of antifreeze and water....You could also try a product called
Water Wetter ...this stuff is supposed to improve the cooling properties of the fluids in your cooling system.
Good luck.
