87 XJ dies out while driving

I am having a problem with my 87 XJ maybe someone can help. My jeep has been dying out on me lately while I'm driving. It's driving fine down the street or on the highway and then all of a sudden I feel a total lost of power and it dies. I try giving it gas but there is no reaction from the motor so I just let it coast till it comes to a stop. Once it stopped I crank it and sometime it start right away and other times I have to let it sit for a while till it starts again. I changed the CPS and it ran good for a couple of days never stoped but then last week it started dying again. I am going to change the O2 sensor maybe that will do something. If anyone has any advice or have a idea what it might be please let me know.

Could be any number of things.
1. Do a search for "RENIX files" lotsa good stuff there.
2. Check fuel pressure at the fuel rail. Should be around 30-40 psi mine is 35. Your fuel pump may be dying, your fuel pump relay may be dying, your fuel filter may be clogged. ALSO check the ballast resistor-- a square white rectangle looking thing mounted on driver fender toward front of vehicle, has two wires attached. Voltage from fuel pump relay feeds through this to power fuel pump. You can bridge this out and see if your problem goes away.