Jeep cuts off

I have a 89 Jeep Cherokee with a 4.0 I6.When you crank it up it runs fine till you start to drive down the road and it get warm then it just dies and cuts off and it want crank up for like 20 minutes. I really need help on this if any body has any ideas to what it is i would appreciate it.:banghead:

Things i have done to it
-Replaced spark plugs and wires
-Replaced all injectors
-Some what cleaned the throttle body
-New distributor and cap and rotor
-New ignition coil and ignition modular